Youssefbou62/sciq_evals · Datasets at Hugging Face

question stringlengths 23 307	choices sequencelengths 4 4	answer stringclasses 4 values	rationale stringlengths 0 2.75k	split stringclasses 1 value	source_dataset stringclasses 1 value	subject null
Who proposed the theory of evolution by natural selection?	[ "darwin", "Scopes", "Linnaeus", "shaw" ]	A		validation	sciq	null
Each specific polypeptide has a unique linear sequence of which acids?	[ "hydrochloric", "lactic", "amino", "fatty" ]	C		validation	sciq	null
A frameshift mutation is a deletion or insertion of one or more of what that changes the reading frame of the base sequence?	[ "proteins", "nucleotides", "genes", "carotenoids" ]	B	A frameshift mutation is a deletion or insertion of one or more nucleotides that changes the reading frame of the base sequence. Deletions remove nucleotides, and insertions add nucleotides. Consider the following sequence of bases in RNA:.	validation	sciq	null
What is an area of land called that is wet for all or part of the year?	[ "wetland", "grassland", "plains", "tundra" ]	A	A wetland is an area that is wet for all or part of the year. Wetlands are home to certain types of plants.	validation	sciq	null
Surface waters are heated by the radiation from?	[ "the moon", "gamma rays", "decomposition", "the sun" ]	D		validation	sciq	null
What are arteries, veins, and capillaries examples of?	[ "muscles", "organs", "blood vessels", "tissue" ]	C	Blood vessels include arteries, veins, and capillaries.	validation	sciq	null
Biochemical reactions of metabolism include what two general categories?	[ "catabolic and anabolic", "innumerable and anabolic", "discrete and telltale", "telltale and anabolic" ]	A	Biochemical reactions of metabolism can be divided into two general categories: catabolic reactions and anabolic reactions. You can watch an animation showing how the two categories of reactions are related at this URL: http://classes. midlandstech. edu/carterp/courses/bio225/chap05/lecture1. htm.	validation	sciq	null
Compounds with aluminum and silicon are commonly found in the clay fractions of soils derived from what?	[ "mineral ash", "volcanic ash", "volatile ash", "ground ash" ]	B	Compounds with aluminum and silicon are commonly found in the clay fractions of soils derived from volcanic ash. One of these compounds is vermiculite, which is formed in reactions caused by exposure to weather. Vermiculite has the following formula: Ca0.7[Si6.6Al1.4]Al4O20(OH)4. (The content of calcium, silicon, and aluminum are not shown as integers because the relative amounts of these elements vary from sample to sample. ) What is the mass percent of each element in this sample of vermiculite?.	validation	sciq	null
What organ has four major regions: the cerebrum, the diencephalon, the stem, and the cerebellum?	[ "heart", "liver", "lungs", "brain" ]	D	13.2 \| The Central Nervous System By the end of this section, you will be able to: • Name the major regions of the adult brain • Describe the connections between the cerebrum and brain stem through the diencephalon, and from those regions into the spinal cord • Recognize the complex connections within the subcortical structures of the basal nuclei • Explain the arrangement of gray and white matter in the spinal cord The brain and the spinal cord are the central nervous system, and they represent the main organs of the nervous system. The spinal cord is a single structure, whereas the adult brain is described in terms of four major regions: the cerebrum, the diencephalon, the brain stem, and the cerebellum. A person’s conscious experiences are based on neural activity in the brain. The regulation of homeostasis is governed by a specialized region in the brain. The coordination of reflexes depends on the integration of sensory and motor pathways in the spinal cord.	validation	sciq	null
What can refer to a rope in a particular shape and a genetic structure involved in splicing?	[ "noose", "tourniquet", "braid", "lariat" ]	D	A lariat can refer to a rope in the form of a lasso. But it is also a genetic structure involved in splicing.	validation	sciq	null
What is the ratio of the mass of an object to its volume?	[ "diameter", "frequency", "median", "density" ]	D	Density is the ratio of the mass of an object to its volume.	validation	sciq	null
What is the most common type of anemia?	[ "vitamin d - def", "calcium - def", "vitamin k - def", "iron-def" ]	D	Anemia may not have any symptoms. Some people with anemia feel weak or tired in general or during exercise. They also may have poor concentration. People with more severe anemia often get short of breath during times of activity. Iron-deficiency anemia is the most common type of anemia. It occurs when the body does not receive enough iron. Since there is not enough iron, hemoglobin, which needs iron to bind oxygen, cannot function properly.	validation	sciq	null
What stimulates milk production in mammals?	[ "prolactin", "estrogen", "testosterone", "neurotoxin" ]	A		validation	sciq	null
During telophase , the chromosomes begin to uncoil and form what?	[ "nucleus", "mucosa", "chromatin", "mitochondria" ]	C	During telophase , the chromosomes begin to uncoil and form chromatin. This prepares the genetic material for directing the metabolic activities of the new cells. The spindle also breaks down, and new nuclear membranes form.	validation	sciq	null
The science dealing with the study of the atmosphere is known as what?	[ "meteorology", "geology", "cosmology", "climatology" ]	A	Meteorologists don’t study meteors—they study the atmosphere! The atmosphere is a thin layer of gas that surrounds Earth. The word “meteor” refers to things in the air. Meteorology includes the study of weather patterns, clouds, hurricanes, and tornadoes. Meteorology is very important. Using radars and satellites, meteorologists work to predict, or forecast, the weather ( Figure below ). Meteorologists are getting better at predicting the weather all the time. Meteorologists wonder how to better predict weather. They wonder what the effects of rising water vapor in the atmosphere will be on weather.	validation	sciq	null
On what basis are the eras of the phanerozoic eon separated?	[ "sparse extinctions", "mass birthings", "low birth rates", "mass extinctions" ]	D	The eras of the Phanerozoic Eon are separated by mass extinctions . During these events, large numbers of organisms became extinct very rapidly. There have been several extinctions in the Phanerozoic. Two mass extinctions stand out more than the others. One took place at the end of the Paleozoic. The other took place at the end of the Mesozoic.	validation	sciq	null
What type of response is generated when a stimulus is received by the nervous system?	[ "a action potential", "a motor response", "a sensory response", "a neural response" ]	B		validation	sciq	null
Fluid in the pseudocoelom serves as a hydrostatic what?	[ "vacuum", "shower", "skeleton", "cell membrane" ]	C		validation	sciq	null
How will global warming eliminate some islands and reduce the area of others?	[ "raise sea levels", "unafect sea levels", "lower sea levels", "affect sea levels" ]	A		validation	sciq	null
What is the term for the secretion of saliva?	[ "perspiration", "excretion", "salivation", "craving" ]	C	Regulation of Salivation The autonomic nervous system regulates salivation (the secretion of saliva). In the absence of food, parasympathetic stimulation keeps saliva flowing at just the right level for comfort as you speak, swallow, sleep, and generally go about life. Over-salivation can occur, for example, if you are stimulated by the smell of food, but that food is not available for you to eat. Drooling is an extreme instance of the overproduction of saliva. During times of stress, such as before speaking in public, sympathetic stimulation takes over, reducing salivation and producing the symptom of dry mouth often associated with anxiety. When you are dehydrated, salivation is reduced, causing the mouth to feel dry and prompting you to take action to quench your thirst. Salivation can be stimulated by the sight, smell, and taste of food. It can even be stimulated by thinking about food. You might notice whether reading about food and salivation right now has had any effect on your production of saliva. How does the salivation process work while you are eating? Food contains chemicals that stimulate taste receptors on the tongue, which send impulses to the superior and inferior salivatory nuclei in the brain stem. These two nuclei then send back parasympathetic impulses through fibers in the glossopharyngeal and facial nerves, which stimulate salivation. Even after you swallow food, salivation is increased to cleanse the mouth and to water down and neutralize any irritating chemical remnants, such as that hot sauce in your burrito. Most saliva is swallowed along with food and is reabsorbed, so that fluid is not lost.	validation	sciq	null
What is the most common sti in the u.s.?	[ "herpes", "syphilis", "chlamydia", "genital warts" ]	C	Chlamydia is the most common STI in the U. S. As shown in the graph in Figure below , females are much more likely than males to develop chlamydia. Like most STIs, rates of chlamydia are highest in teens and young adults.	validation	sciq	null
What plant structures are the main avenues by which water evaporates from the sporophyte?	[ "chloroplasts", "stomata", "chlorophyll", "veins" ]	B		validation	sciq	null
Decomposers break down dead organisms into nutrients and what?	[ "gases", "soil", "fluids", "tissues" ]	A	Decomposers break down dead organisms into nutrients and gases so that they can be used by other organisms.	validation	sciq	null
What is the term for the use of technology to treat genetic disorders or change organisms so they are more useful to people?	[ "biotechnology", "nanotechnology", "biology", "physiology" ]	A	Biotechnology is the use of technology to treat genetic disorders or change organisms so they are more useful to people. Methods include gene cloning. Applications include gene therapy and genetically modified food crops.	validation	sciq	null
What science specialty, with a set of like-named scientific laws, refers to the study of energy and energy transfer involving physical matter?	[ "geology", "thermodynamics", "chemistry", "meteorology" ]	B	6.3 \| The Laws of Thermodynamics By the end of this section, you will be able to: • Discuss the concept of entropy • Explain the first and second laws of thermodynamics Thermodynamics refers to the study of energy and energy transfer involving physical matter. The matter and its environment relevant to a particular case of energy transfer are classified as a system, and everything outside of that system is called the surroundings. For instance, when heating a pot of water on the stove, the system includes the stove, the pot, and the water. Energy is transferred within the system (between the stove, pot, and water). There are two types of systems: open and closed. An open system is one in which energy can be transferred between the system and its surroundings. The stovetop system is open because heat can be lost into the air. A closed system is one that cannot transfer energy to its surroundings. Biological organisms are open systems. Energy is exchanged between them and their surroundings, as they consume energystoring molecules and release energy to the environment by doing work. Like all things in the physical world, energy is subject to the laws of physics. The laws of thermodynamics govern the transfer of energy in and among all systems in the universe.	validation	sciq	null
What type of tissue makes up the brain and the nerves that connect the brain to all parts of the body?	[ "benign tissue", "nervous tissue", "neurotransmitters", "peripheral tissue" ]	B	Nervous tissue is made up of neurons, or nerve cells, that carry electrical messages. Nervous tissue makes up the brain and the nerves that connect the brain to all parts of the body.	validation	sciq	null
Periodic refers to something that does what?	[ "fail", "dies", "falls", "repeat" ]	D	Mendeleev’s table of the elements is called a periodic table because of its repeating pattern. Anything that keeps repeating is referred to as periodic. Other examples of things that are periodic include the monthly phases of the moon and the daily cycle of night and day. The term period refers to the interval between repetitions. In a periodic table, the periods are the rows of the table. In Mendeleev’s table, each period contains eight elements, and then the pattern repeats in the next row.	validation	sciq	null
Blood is pumped from the heart, pushing open which valves?	[ "aortic and carotid", "pulmonary and respiratory", "pulmonary and aortic semilunar", "thoracic and aortic" ]	C	Ventricular Systole Ventricular systole (see Figure 19.27) follows the depolarization of the ventricles and is represented by the QRS complex in the ECG. It may be conveniently divided into two phases, lasting a total of 270 ms. At the end of atrial systole and just prior to atrial contraction, the ventricles contain approximately 130 mL blood in a resting adult in a standing position. This volume is known as the end diastolic volume (EDV) or preload. Initially, as the muscles in the ventricle contract, the pressure of the blood within the chamber rises, but it is not yet high enough to open the semilunar (pulmonary and aortic) valves and be ejected from the heart. However, blood pressure quickly rises above that of the atria that are now relaxed and in diastole. This increase in pressure causes blood to flow back toward the atria, closing the tricuspid and mitral valves. Since blood is not being ejected from the ventricles at this early stage, the volume of blood within the chamber remains constant. Consequently, this initial phase of ventricular systole is known as isovolumic contraction, also called isovolumetric contraction (see Figure 19.27). In the second phase of ventricular systole, the ventricular ejection phase, the contraction of the ventricular muscle has raised the pressure within the ventricle to the point that it is greater than the pressures in the pulmonary trunk and the aorta. Blood is pumped from the heart, pushing open the pulmonary and aortic semilunar valves. Pressure generated by the left ventricle will be appreciably greater than the pressure generated by the right ventricle, since the existing pressure in the aorta will be so much higher. Nevertheless, both ventricles pump the same amount of blood. This quantity is referred to as stroke volume. Stroke volume will normally be in the range of 70–80 mL. Since ventricular systole began with an EDV of approximately 130 mL of blood, this means that there is still 50–60 mL of blood remaining in the ventricle following contraction. This volume of blood is known as the end systolic volume (ESV).	validation	sciq	null
What term refers to a list of the elements that will replace the ones below them in single-replacement reactions?	[ "activity series", "growth series", "Up series", "probably series" ]	A	Chemical reactivity trends are easy to predict when replacing anions in simple ionic compounds—simply use their relative positions on the periodic table. However, when replacing the cations, the trends are not as straightforward. This is partly because there are so many elements that can form cations; an element in one column on the periodic table may replace another element nearby, or it may not. A list called the activity series does the same thing the periodic table does for halogens: it lists the elements that will replace elements below them in single-replacement reactions. A simple activity series is shown below.	validation	sciq	null
What cause many human diseases by killing host cells or disturbing their homeostasis?	[ "bacteria", "cancer", "parasites", "viruses" ]	D	Viruses cause many human diseases by killing host cells or disturbing their homeostasis. Viruses are not affected by antibiotics. Several viral diseases can be treated with antiviral drugs or prevented with vaccines.	validation	sciq	null
What two types of digestive systems do invertebrates have?	[ "slow or complete", "fast or slow", "incomplete or complete", "unstable or complete" ]	C	Invertebrates have one of two types of digestive system: an incomplete or complete digestive system. Both are shown in Figure below . An incomplete digestive system consists of a digestive cavity with one opening. The single opening serves as both mouth and anus. A complete digestive system consists of a digestive tract with two openings. One opening is the mouth. The other is the anus.	validation	sciq	null
What are ectothermic vertebrates that divide their time between freshwater and terrestrial habitats?	[ "amphibians", "arthropods", "mammals", "reptiles" ]	A	Amphibians are ectothermic vertebrates that divide their time between freshwater and terrestrial habitats.	validation	sciq	null
During exercise, the rate of blood returning to the heart does this?	[ "reduces", "remains stable", "increases", "changes randomly" ]	C	Correlation Between Heart Rates and Cardiac Output Initially, physiological conditions that cause HR to increase also trigger an increase in SV. During exercise, the rate of blood returning to the heart increases. However as the HR rises, there is less time spent in diastole and consequently less time for the ventricles to fill with blood. Even though there is less filling time, SV will initially remain high. However, as HR continues to increase, SV gradually decreases due to decreased filling time. CO will initially stabilize as the increasing HR compensates for the decreasing SV, but at very high rates, CO will eventually decrease as increasing rates are no longer able to compensate for the decreasing SV. Consider this phenomenon in a healthy young individual. Initially, as HR increases from resting to approximately 120 bpm, CO will rise. As HR increases from 120 to 160 bpm, CO remains stable, since the increase in rate is offset by decreasing ventricular filling time and, consequently, SV. As HR continues to rise above 160 bpm, CO actually decreases as SV falls faster than HR increases. So although aerobic exercises are critical to maintain the health of the heart, individuals are cautioned to monitor their HR to ensure they stay within the target heart rate range of between 120 and 160 bpm, so CO is maintained. The target HR is loosely defined as the range in which both the heart and lungs receive the maximum benefit from the aerobic workout and is dependent upon age.	validation	sciq	null
What is the pattern of spacing among individuals within the boundaries of the population?	[ "equilibrium", "dispersion", "diffusion", "frequency" ]	B		validation	sciq	null
What level is a feeding position in a food chain or web?	[ "singular", "trophic", "neural", "differentiation" ]	B	Each food chain or food web has organisms at different trophic levels. A trophic level is a feeding position in a food chain or web. The trophic levels are identified in the food web in Figure above . All food chains and webs have at least two or three trophic levels, but they rarely have more than four trophic levels. The trophic levels are:.	validation	sciq	null
What do most of the noble gas elements have in common?	[ "zero valence electrons", "eight valence electrons", "four valence electrons", "two valence electrons" ]	B	Atoms can join together by forming a chemical bond, which is a very strong attraction between two atoms. Chemical bonds are formed when electrons in different atoms interact with each other to make an arrangement that is more stable than when the atoms are apart. What causes atoms to make a chemical bond with other atoms, rather than remaining as individual atoms? A clue comes by considering the noble gas elements, the rightmost column of the periodic table. These elements—helium, neon, argon, krypton, xenon, and radon—do not form compounds very easily, which suggests that they are especially stable as lone atoms. What else do the noble gas elements have in common? Except for helium, they all have eight valence electrons. Chemists have concluded that atoms are especially stable if they have eight electrons in their outermost shell. This useful rule of thumb is called the octet rule, and it is a key to understanding why compounds form.	validation	sciq	null
What are the organisms that live in extreme conditions known as?	[ "fibroblasts", "extremophiles", "naturophiles", "carotenoids" ]	B	Many archaeans are extremophiles. Extremophiles are organisms that live in extreme conditions. For example, some archaeans live around hydrothermal vents. A hydrothermal vent is a crack on the ocean floor. You can see one in Figure below . Boiling hot, highly acidic water pours out of the vent. These extreme conditions don't deter archaeans. They have evolved adaptations for coping with them. These conditions are like those on ancient Earth. This suggests that archaeans may have evolved very early in Earth's history.	validation	sciq	null
Collision frequency is greater for what category of catalysts, which also tend to be more sensitive to temperature and more 'expensive'?	[ "analogous", "homogeneous", "heterogeneous", "contiguous" ]	B	Heterogeneous catalysts are easier to recover. Collision frequency is greater for homogeneous catalysts. Homogeneous catalysts are often more sensitive to temperature. Homogeneous catalysts are often more expensive. Saylor URL: http://www. saylor. org/books.	validation	sciq	null
What does the pull of the moon's gravity on earth cause?	[ "earthquakes", "storms", "tides", "waves" ]	C	Figure below shows why tides occur. The main cause of tides is the pull of the Moon’s gravity on Earth. The pull is greatest on whatever is closest to the Moon. Although the gravity pulls the land, only the water can move. As a result:.	validation	sciq	null
A water molecule forms when oxygen (o) and _______ atoms react and are held together by covalent bonds?	[ "nitrogen", "hydrogen (h)", "carbon", "steam" ]	B	An example of a chemical compound is water. A water molecule forms when oxygen (O) and hydrogen (H) atoms react and are held together by covalent bonds. Like other compounds, water always has the same chemical composition: a 2:1 ratio of hydrogen atoms to oxygen atoms. This is expressed in the chemical formula H 2 O. A model of a water molecule is shown in Figure below .	validation	sciq	null
What force makes objects seem lighter in water?	[ "buoyant", "resilient", "surface tension", "gravity" ]	A	Because of buoyant force, objects seem lighter in water. You may have noticed this when you went swimming and could easily pick up a friend or sibling under the water. Some of the person’s weight was countered by the buoyant force of the water.	validation	sciq	null
What is the process by which the nucleus of a eukaryotic cell divides?	[ "meiosis", "cytokinesis", "mitosis", "angiogenesis" ]	C	Mitosis is the process by which the nucleus of a eukaryotic cell divides. It happens in four phases: prophase, metaphase, anaphase, and telophase.	validation	sciq	null
Iceland is made up of a series of?	[ "glaciers", "volcanoes", "outcrops", "earthquakes" ]	B	A fissure eruption on a volcano in Iceland. The lava flows downhill and turns snow into steam. Iceland is made of a set of volcanoes that are the result of a hotspot that lies on a mid-ocean ridge. The island is the only location where the mid-ocean ridge can be seen above sea level. Icelandic volcanoes have made the news lately since some have shut down air traffic in parts of Europe.	validation	sciq	null
What type of organism does not need oxygen for growth and dies in its presence?	[ "aerobic", "symbiotic", "anaerobic", "acidic" ]	C	An anaerobic organism is any organism that does not need oxygen for growth and even dies in its presence. Obligate anaerobes will die when exposed to atmospheric levels of oxygen. Clostridium perfringens bacteria, which are commonly found in soil around the world, are obligate anaerobes. Infection of a wound by C. perfringens bacteria causes the disease gas gangrene. Obligate anaerobes use molecules other than oxygen as terminal electron acceptors.	validation	sciq	null
What is the name of specialized organs that filter the lymph by percolation through a maze of connective tissue filled with white blood cells?	[ "cochlea", "alveoli", "lymph nodes", "edema glands" ]	C	eventually diffuses back into the capillaries near the venules. The remaining 15% of blood plasma drains out from the interstitial fluid into nearby lymphatic vessels (Figure 40.18). The fluid in the lymph is similar in composition to the interstitial fluid. The lymph fluid passes through lymph nodes before it returns to the heart via the vena cava. Lymph nodes are specialized organs that filter the lymph by percolation through a maze of connective tissue filled with white blood cells. The white blood cells remove infectious agents, such as bacteria and viruses, to clean the lymph before it returns to the bloodstream. After it is cleaned, the lymph returns to the heart by the action of smooth muscle pumping, skeletal muscle action, and one-way valves joining the returning blood near the junction of the venae cavae entering the right atrium of the heart.	validation	sciq	null
What are hydrocarbons most important use?	[ "lightsource", "fuel", "electricity", "food" ]	B	Hydrocarbons have a wide variety of important uses, but their most important use is as fuels.	validation	sciq	null
What protects tissues of the central nervous system from changes in ph?	[ "sucrose ions", "bicarbonate ions", "fatty ions", "cerebrum" ]	B	Bicarbonate ions play an important role in neutralizing acids throughout the body. Bicarbonate ions are especially important for protecting tissues of the central nervous system from changes in pH. The central nervous system includes the brain, which is the body’s control center. If pH deviates too far from normal, the central nervous system cannot function properly. This can have a drastic effect on the rest of the body.	validation	sciq	null
The air pressure is about 80% that of ________ pressure at sea level.	[ "adverse atmospheric", "standard atmospheric", "internal atmospheric", "specific atmospheric" ]	B	The air pressure is about 80% that of standard atmospheric pressure at sea level. For significant figure purposes, the standard pressure of 760 mmHg has three significant figures.	validation	sciq	null
Vertebrates - including fish, amphibians, reptiles, birds, and mammals - belong to what phylum?	[ "nematota", "chordata", "animalia", "angulata" ]	B	Vertebrates are animals in Phylum Chordata. Modern vertebrates include fish, amphibians, reptiles, birds, and mammals. You can see examples of all these groups of vertebrates in Figure below .	validation	sciq	null
In our wildflower population, the pool of what remains constant from one generation to the next?	[ "genes", "genomes", "DNA", "eggs" ]	A		validation	sciq	null
When a membrane uses energy to move a substance across it, what kind of transport is this?	[ "fast", "inactive", "active", "slow" ]	C	x rms = 2Dt, where D is the diffusion constant, representative values of which are found in Table 12.2. • Osmosis is the transport of water through a semipermeable membrane from a region of high concentration to a region of low concentration. • Dialysis is the transport of any other molecule through a semipermeable membrane due to its concentration difference. • Both processes can be reversed by back pressure. • Active transport is a process in which a living membrane expends energy to move substances across it.	validation	sciq	null
An electrostatic attraction between two ions that have exchanged what?	[ "neutrons", "electrons", "quasars", "protons" ]	B	An electrostatic attraction between two ions that have exchanged electrons.	validation	sciq	null
During what part of a person's development are they generally at their physical peak?	[ "senility", "early adulthood", "late adulthood", "infancy" ]	B	Early adulthood starts at age 18 or 21. It continues until the mid-30s. During early adulthood, people are at their physical peak. They are also usually in good health. The ability to have children is greatest during early adulthood, as well. This is the stage of life when most people complete their education. They are likely to begin a career or take a full-time job. Many people also marry and start a family during early adulthood.	validation	sciq	null
What type of movement involves sluggish segmentation, primarily in the transverse and descending colons?	[ "haustral contraction", "gasutral contraction", "photoreactive contraction", "accompanying contraction" ]	A	Mechanical Digestion In the large intestine, mechanical digestion begins when chyme moves from the ileum into the cecum, an activity regulated by the ileocecal sphincter. Right after you eat, peristalsis in the ileum forces chyme into the cecum. When the cecum is distended with chyme, contractions of the ileocecal sphincter strengthen. Once chyme enters the cecum, colon movements begin. Mechanical digestion in the large intestine includes a combination of three types of movements. The presence of food residues in the colon stimulates a slow-moving haustral contraction. This type of movement involves sluggish segmentation, primarily in the transverse and descending colons. When a haustrum is distended with chyme, its muscle contracts, pushing the residue into the next haustrum. These contractions occur about every 30 minutes, and each last about 1 minute. These movements also mix the food residue, which helps the large intestine absorb water. The second type of movement is peristalsis, which, in the large intestine, is slower than in the more proximal portions of the alimentary canal. The third type is a mass movement. These strong waves start midway through the transverse colon and quickly force the contents toward the rectum. Mass movements usually occur three or four times per day, either while you eat or immediately afterward. Distension in the stomach and the breakdown products of digestion in the small intestine provoke the gastrocolic reflex, which increases motility, including mass movements, in the colon. Fiber in the diet both softens the stool and increases the power of colonic contractions, optimizing the activities of the colon.	validation	sciq	null
Vertebrates evolved from primitive forms of which creature?	[ "cephalopods", "gastropods", "chordates", "eukaryotes" ]	C	Vertebrates evolved from primitive chordates. This occurred about 550 million years ago. The earliest vertebrates may have been jawless fish, like the hagfish in Figure below . Vertebrates evolved a backbone to replace the notochord after the embryo stage. They also evolved a cranium, or bony skull, to enclose and protect the brain.	validation	sciq	null
What does the aqueous fluid between the chloroplast membrane and the grana known as?	[ "plasma", "water", "blood", "stroma" ]	D	Both chloroplasts and photosynthetic bacteria contain grana, neat stacks of flattened sac-shaped membrane compartments called thylakoids . Thylakoids can be considered a sub-organelle within the chloroplast. Between the chloroplast membrane and the grana is an aqueous fluid known as stroma . Thylakoids, especially the thylakoid membrane, organize patterns of proteins and other molecules which conduct photosynthesis, as shown in Figure below . In addition to enzymes, two basic types of molecules - pigments and electron carriers – are significant in this process. You can take a video tour of a chloroplast at Encyclopedia Britannica: Chloroplast : http://www. britannica. com/EBchecked/media/16440/Chloroplasts-circulate-within-plant-cells .	validation	sciq	null
When a hypothesis is repeatedly confirmed, what can it then become?	[ "study", "evolution", "theory", "Thesis" ]	C	When a hypothesis is confirmed repeatedly, it eventually becomes a theory – a general principle that is offered to explain natural phenomena. Note a key word – explanation. The theory offers a description of why something happens. A law, on the other hand, is a statement that is always true, but does not explain why. The law of gravity says a rock will fall when dropped, but does not explain why (gravitational theory is very complex and incomplete at present). The kinetic-molecular theory of gases, on the other hand, tells what happens when a gas is heated in a closed container (the pressure increases), but also explains why (the motions of the gas molecules are increased due to the change in temperature). Theories do not get “promoted” to laws because laws do not answer the “why” question.	validation	sciq	null
Using a hammer to remove a nail changes both the direction and strength of the what?	[ "applied force", "static energy", "gravity", "kinetic energy" ]	A	Using a hammer to remove a nail changes both the direction and strength of the applied force. Where is the fulcrum of the hammer when it is used in this way?.	validation	sciq	null
Through which process are plants able to make their own food?	[ "metabolism", "cell division", "glycolysis", "photosynthesis" ]	D		validation	sciq	null
What kind of waves are sound waves?	[ "spinning", "mechanical", "internal", "External" ]	B	A: It wouldn’t unless the vibrations were carried by another medium. Sound waves are mechanical waves, so they can travel only though matter and not through empty space.	validation	sciq	null
The protein without the prosthetic group is known as the what?	[ "spicule", "monoprotein", "xerophyte", "apoprotein" ]	D	As we will return to later, proteins are functional entities, composed of polypeptides and prosthetic group. The prosthetic group is essential for normal protein function. The protein without the prosthetic group is known as the apoprotein. biofundamentals – coreBIO.	validation	sciq	null
What connections allow heterocysts to transport fixed nitrogen to neighboring cells and to receive carbohydrates?	[ "neurons", "peptide", "heterogeneity", "intercellular" ]	D		validation	sciq	null
The classes anthozoa, scyphozoa, cubozoa, and hydrozoa make up what phylum?	[ "cnidaria", "mollusca", "crinoids", "poriferia" ]	A	differentiated cell types in each tissue layer, such as nerve cells, enzyme-secreting cells, and nutrient-absorbing cells, as well as intercellular connections between the cells. However, organs and organ systems are not present in this phylum. The nervous system is primitive, with nerve cells scattered across the body in a network. The function of the nerve cells is to carry signals from sensory cells and to contractile cells. Groups of cells in the nerve net form nerve cords that may be essential for more rapid transmission. Cnidarians perform extracellular digestion, with digestion completed by intracellular digestive processes. Food is taken into the gastrovascular cavity, enzymes are secreted into the cavity, and the cells lining the cavity absorb the nutrient products of the extracellular digestive process. The gastrovascular cavity has only one opening that serves as both a mouth and an anus (an incomplete digestive system). Like the sponges, Cnidarian cells exchange oxygen, carbon dioxide, and nitrogenous wastes by diffusion between cells in the epidermis and gastrodermis with water. Cnidarian Diversity The phylum Cnidaria contains about 10,000 described species divided into four classes: Anthozoa, Scyphozoa, Cubozoa, and Hydrozoa. The class Anthozoa includes all cnidarians that exhibit a sessile polyp body plan only; in other words, there is no medusa stage within their life cycle. Examples include sea anemones, sea pens, and corals, with an estimated number of 6,100 described species. Sea anemones are usually brightly colored and can attain a size of 1.8 to 10 cm in diameter. These animals are usually cylindrical in shape and are attached to a substrate. A mouth opening is surrounded by tentacles bearing cnidocytes (Figure 15.12).	validation	sciq	null
Where does waste enter the large intestine from?	[ "the small intestine", "kidneys", "the small tissue", "liver" ]	A	The large intestine is a wide tube that connects the small intestine with the anus. In adults, it is about five feet long. Waste enters the large intestine from the small intestine in a liquid state. As the waste moves through the large intestine, excess water is absorbed from it. After the excess water is absorbed, the remaining solid waste is called feces.	validation	sciq	null
What do different soil horizons show different amounts of?	[ "evolution", "alteration", "distortion", "secretion" ]	B	Soil horizons are layers within a soil. Different soil horizons show different amounts of alteration.	validation	sciq	null
What is the main source of energy for your body?	[ "vitamins", "proteins", "carbohydrates", "fats" ]	C	Carbohydrates, proteins, and lipids are categories of organic compounds. They give your body energy, though carbohydrates are the main source of energy. Proteins provide building materials, such as amino acids to build your own proteins. Proteins, vitamins, and minerals also help control body processes. Carbohydrates include sugars such as the glucose made by photosynthesis. Often glucose is stored in large molecules such as starch. Proteins are found in foods like meats and nuts. Lipids includes fats and oils. Though you should stay away from many types of fats, others are needed by your body. Important vitamins include vitamins A, B (multiple types) C, D, and E. Important minerals include calcium and potassium. What should you drink to get calcium? Milk is a good source.	validation	sciq	null
What are thin, very small tail-like projections that extend outward from the cell body that allow protists to move?	[ "cilia", "notochords", "fins", "antennae" ]	A	The ciliates are protists that move by using cilia. Cilia are thin, very small tail-like projections that extend outward from the cell body. Cilia beat back and forth, moving the protist along. Paramecium has cilia that propel it.	validation	sciq	null
Earthquakes, which may occur on california’s abundant faults, can also trigger what?	[ "Waves", "landslides", "avalanches", "floods" ]	B	Some communities have developed landslide warning systems. Around San Francisco Bay, the National Weather Service and the U. S. Geological Survey use rain gauges to monitor soil moisture. If soil becomes saturated, the weather service issues a warning. Earthquakes, which may occur on California’s abundant faults, can also trigger landslides.	validation	sciq	null
In which way do particles of water move in deep water?	[ "parabolas", "currents", "circles", "ellipses" ]	C	In deep water, particles of water just move in circles. They don’t actually move closer to shore with the energy of the waves. However, near the shore where the water is shallow, the waves behave differently. They start to drag on the bottom, creating friction (see Figure below ). The friction slows down the bottoms of the waves, while the tops of the waves keep moving at the same speed. This causes the waves to get steeper until they topple over and crash on the shore. The crashing waves carry water onto the shore as surf.	validation	sciq	null
What is the name of the study of heat engines?	[ "Chemical dynamics", "chemistry", "biology", "thermodynamics" ]	D	Thermodynamics is the study of heat engines. Any engine or power plant obeys the laws of thermodynamics. The first law of thermodynamics is a statement of conservation of energy. Total energy, including heat, is conserved in any process and in the complete cycle of a heat engine. The second law of thermodynamics as it applies to heat engines gives an absolute limit on the efficiency of any heat engine that goes through repetitious cycles.	validation	sciq	null
Mechanical waves can only trave through what?	[ "air", "light", "matter", "water" ]	C	The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium ( plural , media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid.	validation	sciq	null
If you examine eyeglasses for nearsighted people, you will find the lenses are thinnest in the center and of what shape?	[ "convex", "asymmetrical", "square", "concave" ]	D	Discussion The negative power indicates a diverging (or concave) lens, as expected. The spectacle produces a case 3 image closer to the eye, where the person can see it. If you examine eyeglasses for nearsighted people, you will find the lenses are thinnest in the center. Additionally, if you examine a prescription for eyeglasses for nearsighted people, you will find that the prescribed power is negative and given in units of diopters.	validation	sciq	null
What do you call air flowing over earth’s surface?	[ "gas", "air pressure", "steam", "wind" ]	D	Air always flows from an area of higher pressure to an area of lower pressure. Air flowing over Earth’s surface is called wind . The greater the difference in pressure, the stronger the wind blows.	validation	sciq	null
What three particles make up most atoms?	[ "protons, electrons and nucleus", "micrometres , electrons and neutrons", "neutrons, protons and radii", "protons, electrons and neutrons" ]	D	A neutron is one of three main particles that make up the atom. The other two particles are the proton and electron. Atoms of all elements—except for most atoms of hydrogen—have neutrons in their nucleus. The nucleus is the small, dense region at the center of an atom where protons are also found. Atoms generally have about the same number of neutrons as protons. For example, all carbon atoms have six protons and most also have six neutrons. A model of a carbon atom is shown in the Figure below . For an excellent video explaining the structure of atoms, including neutrons, go to this URL:.	validation	sciq	null
How can one dimensional vectors be added?	[ "exponentially", "incrementally", "sequentially", "arithmetically" ]	D	Vectors that are in one dimension can be added arithmetically.	validation	sciq	null
What is caused by the reaction of nonmetal oxides with water in the atmosphere?	[ "yellow rain", "acid rain", "ozone rain", "carbon rain" ]	B	Acid rain is caused by the reaction of nonmetal oxides with water in the atmosphere. One such reaction involves nitrogen dioxide (NO2) and produces nitric acid (HNO3): 3NO2 + H2O → 2HNO3 + NO If 1.82 × 1013 g of NO2 enter the atmosphere every year due to human activities, potentially how many grams of HNO3 can be produced annually?.	validation	sciq	null
Into how many basic regions can the aquatic biome be broken down?	[ "six", "two", "five", "One" ]	B		validation	sciq	null
The top of the saturated rock layer is called what?	[ "sand layer", "water table", "calcified layer", "compressed layer" ]	B	The top of the saturated rock layer above ( Figure above ) is called the water table . The water table isn’t like a real table. It doesn’t remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain, and it is lower when the weather is dry.	validation	sciq	null
Which field studies how to tailor medical treatments to our genetic profiles?	[ "metagenomics", "immunology", "pharmacogenomics", "proteomics" ]	C	We know that, thanks to our DNA, each of us is a little bit different. Some of those differences are obvious, like eye and hair color. Others are not so obvious, like how our bodies react to medication. Researchers are beginning to look at how to tailor medical treatments to our genetic profiles, in a relatively new field called pharmacogenomics . Some of the biggest breakthroughs have been in cancer treatment. For additional information on this “personalized medicine,” listen to http://www. kqed. org/quest/radio/personalized-medicine and see http://www. kqed. org/quest/blog/2009/09/11/reporters-notes-personalized-medicine/ .	validation	sciq	null
Research that focuses on understanding basic properties and processes without concern for the usefulness of this understanding is known as what kind of research?	[ "applied research", "pure research", "disconnected research", "focused research" ]	B	Pure research focuses on understanding basic properties and processes.	validation	sciq	null
Cells of what category of organisms can be organized at the level of cells, tissues, organs, and organ systems?	[ "multicellular", "biomolecular", "intricate", "complex" ]	A	Cells can exist independently as single-celled organisms or with other cells as multicellular organisms. Cells of a multicellular organism can be organized at the level of cells, tissues, organs, and organ systems.	validation	sciq	null
What property of materials describes the ease in which they can be molded into thin sheets?	[ "rigidity", "malleability", "plasticity", "permeability" ]	B	A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Silver is a shiny metal that conducts electricity very well. It can be molded into thin sheets, a property called malleability. Salt is dull and brittle and conducts electricity when it has been dissolved into water, which it does quite easily. Physical properties of matter include color, hardness, malleability, solubility, electrical conductivity, density, melting points , and boiling points .	validation	sciq	null
What do you call materials that have low resistance to electric current?	[ "electric conductors", "electromagnets", "poor conductors", "good insulator" ]	A	Materials that have low resistance to electric current are called electric conductors . Many metals—including copper, aluminum, and steel—are good conductors of electricity. The outer electrons of metal atoms are loosely bound and free to move, allowing electric current to flow. Water that has even a tiny amount of impurities is an electric conductor as well.	validation	sciq	null
What is the term for the transfer of heat by a current?	[ "radiation", "diffusion", "convection", "conduction" ]	C	Convection is the transfer of heat by a current. Convection happens in a liquid or a gas. Air near the ground is warmed by heat radiating from Earth's surface. The warm air is less dense, so it rises. As it rises, it cools. The cool air is dense, so it sinks to the surface. This creates a convection current ( Figure below ). Convection is the most important way that heat travels in the atmosphere.	validation	sciq	null
Arterioles receive blood from arteries, which are vessels with a much larger lumen. as their own lumen averages just 30 micrometers or less, arterioles are critical in slowing down—or resisting—blood flow. the arterioles can also constrict or dilate, which varies their what?	[ "resistance", "osmosis", "advantage", "gravity" ]	A	Chapter 20 1 Water. 3 A 5 C 7 C 9 A 11 D 13 B 15 A 17 C 19 A 21 C 23 D 25 D 27 C 28 Arterioles receive blood from arteries, which are vessels with a much larger lumen. As their own lumen averages just 30 micrometers or less, arterioles are critical in slowing down—or resisting—blood flow. The arterioles can also constrict or dilate, which varies their resistance, to help distribute blood flow to the tissues. 30 This is a venule. 32 People who stand upright all day and are inactive overall have very little skeletal muscle activity in the legs. Pooling of blood in the legs and feet is common. Venous return to the heart is reduced, a condition that in turn reduces cardiac output and therefore oxygenation of tissues throughout the body. This could at least partially account for the patient’s fatigue and shortness of breath, as well as her “spaced out” feeling, which commonly reflects reduced oxygen to the brain. 34 False. The plasma proteins suspended in blood cannot cross the semipermeable capillary cell membrane, and so they remain in the plasma within the vessel, where they account for the blood colloid osmotic pressure. 36 Nitric oxide is a very powerful local vasodilator that is important in the autoregulation of tissue perfusion. If it were not broken down very quickly after its release, blood flow to the region could exceed metabolic needs. 38 The gonadal veins drain the testes in males and the ovaries in females. 40 Angiogenesis inhibitors are drugs that inhibit the growth of new blood vessels. They can impede the growth of tumors by limiting their blood supply and therefore their access to gas and nutrient exchange.	validation	sciq	null
What is the circular center of a hurricane better known as?	[ "the nose", "the eye", "the epicenter", "the focus" ]	B	At the center of a hurricane is a small area where the air is calm and clear. This is called the eye of the hurricane ( Figure below ). The eye forms at the low-pressure center of the hurricane. Air in the eye rises upward.	validation	sciq	null
Are most glaciers currently growing or shrinking?	[ "growing", "shrinking", "freezing", "no change" ]	B	Glaciers are not static; they grow, they move and they shrink. Currently, most glaciers are shrinking.	validation	sciq	null
What kind of model - which includes producers, consumers and decomposers - shows the interactions between organisms across trophic levels?	[ "interdepence web", "organic web", "food web", "fuel web" ]	C	Figure 20.6 This food web shows the interactions between organisms across trophic levels. Arrows point from an organism that is consumed to the organism that consumes it. All the producers and consumers eventually become nourishment for the decomposers (fungi, mold, earthworms, and bacteria in the soil). (credit "fox": modification of work by Kevin Bacher, NPS; credit "owl": modification of work by John and Karen Hollingsworth, USFWS; credit "snake": modification of work by Steve Jurvetson; credit "robin": modification of work by Alan Vernon; credit "frog": modification of work by Alessandro Catenazzi; credit "spider": modification of work by "Sanba38"/Wikimedia Commons; credit "centipede": modification of work by “Bauerph”/Wikimedia Commons; credit "squirrel": modification of work by Dawn Huczek; credit "mouse": modification of work by NIGMS, NIH; credit "sparrow": modification of work by David Friel; credit "beetle": modification of work by Scott Bauer, USDA Agricultural Research Service; credit "mushrooms": modification of work by Chris Wee; credit "mold": modification of work by Dr. Lucille Georg, CDC; credit "earthworm": modification of work by Rob Hille; credit "bacteria": modification of work by Don Stalons, CDC).	validation	sciq	null
The multifidus muscle of the lumbar region helps extend and laterally flex this?	[ "vertebal column", "knee", "forearm", "pelvic muscle" ]	A	are associated. The semispinalis muscles include the semispinalis capitis, the semispinalis cervicis, and the semispinalis thoracis. The multifidus muscle of the lumbar region helps extend and laterally flex the vertebral column. Important in the stabilization of the vertebral column is the segmental muscle group, which includes the interspinales and intertransversarii muscles. These muscles bring together the spinous and transverse processes of each consecutive vertebra. Finally, the scalene muscles work together to flex, laterally flex, and rotate the head. They also contribute to deep inhalation. The scalene muscles include the anterior scalene muscle (anterior to the middle scalene), the middle scalene muscle (the longest, intermediate between the anterior and posterior scalenes), and the posterior scalene muscle (the smallest, posterior to the middle scalene).	validation	sciq	null
What does k stand for on the periodic table?	[ "magnesium", "aluminum", "potassium", "calcium" ]	C	Q: The table shown in the Figure above is called the periodic table of the elements. Each symbol stands for a different element. What do you think the symbol K stands for?.	validation	sciq	null
Beta decay occurs when a nucleus has too few of what relative to protons?	[ "protons", "nuclei", "electrons", "neutrons" ]	D	Beta decay occurs when a nucleus is unstable because it has too many or too few neutrons relative to protons. The nucleus emits a beta particle and energy. A beta particle is either an electron (beta-minus decay) or a positron (beta-plus decay).	validation	sciq	null
Trees have woody stems covered with what?	[ "larvae", "shells", "rust", "bark" ]	D	Trees have woody stems covered with bark.	validation	sciq	null
What prevents an object from moving in a straight line at a constant speed?	[ "friction", "force", "matter", "weight" ]	B	Newton’s first law implies that an object oscillating back and forth is experiencing forces. Without force, the object would move in a straight line at a constant speed rather than oscillate. Consider, for example, plucking a plastic ruler to the left as shown in Figure 16.2. The deformation of the ruler creates a force in the opposite direction, known as a restoring force. Once released, the restoring force causes the ruler to move back toward its stable equilibrium position, where the net force on it is zero. However, by the time the ruler gets there, it gains momentum and continues to move to the right, producing the opposite deformation. It is then forced to the left, back through equilibrium, and the process is repeated until dissipative forces dampen the motion. These forces remove mechanical energy from the system, gradually reducing the motion until the ruler comes to rest. The simplest oscillations occur when the restoring force is directly proportional to displacement. When stress and strain were covered in Newton’s Third Law of Motion, the name was given to this relationship between force and displacement was Hooke’s law:.	validation	sciq	null
The effect of acetylcholine in heart muscle is inhibitory rather than what?	[ "olfactory", "excitatory", "neurotransmitter", "exofactory" ]	B		validation	sciq	null
What is the division of the cytoplasm in eukaryotic cells?	[ "cytokinesis", "metamorphosis", "andronisis", "electrolysis" ]	A	The second major step is cytokinesis . As in prokaryotic cells, the cytoplasm must divide. Cytokinesis is the division of the cytoplasm in eukaryotic cells, resulting in two genetically identical daughter cells.	validation	sciq	null
The white of an egg becomes opaque when cooked because what are insoluble and solidify?	[ "fatty acids", "calcium molecules", "acetic proteins", "denatured proteins" ]	D		validation	sciq	null
What kind of plants lack xylem or phloem to transport nutrients, water, and food?	[ "trichina", "nonvascular", "single-celled", "spicule" ]	B	Nonvascular plants evolved first. They are distinct from the algae because they keep the embryo inside of the reproductive structure after fertilization. These plants do not have vascular tissue, xylem or phloem, to transport nutrients, water, and food. Examples include mosses, liverworts, and hornworts. Without vascular tissue, these plants do not grow very tall.	validation	sciq	null
Exemplified by baring teeth, what type of displays are common in the animal kingdom, and sometimes serve as a 'bluff'?	[ "aggressive", "passive", "defensive", "sexual" ]	A	incorrectly or a proper response is not given, the mating ritual is abandoned and the mating attempt will be unsuccessful. The mating display of the common stork is shown in Figure 45.37. Aggressive displays are also common in the animal kingdom. An example is when a dog bares its teeth when it wants another dog to back down. Presumably, these displays communicate not only the willingness of the animal to fight, but also its fighting ability. Although these displays do signal aggression on the part of the sender, it is thought that these displays are actually a mechanism to reduce the amount of actual fighting that occurs between members of the same species: they allow individuals to assess the fighting ability of their opponent and thus decide whether it is “worth the fight. ” The testing of certain hypotheses using game theory has led to the conclusion that some of these displays may overstate an animal’s actual fighting ability and are used to “bluff” the opponent. This type of interaction, even if “dishonest,” would be favored by natural selection if it is successful more times than not.	validation	sciq	null
The preferred phase a substance adopts can change with temperature. at low temperatures, most substances are solids (only helium is predicted to be a liquid at absolute zero). as the temperature increases, those substances with very weak intermolecular forces become gases directly in a process called this?	[ "sublimation", "vaporization", "Freezing Point", "speciation" ]	A	The preferred phase a substance adopts can change with temperature. At low temperatures, most substances are solids (only helium is predicted to be a liquid at absolute zero). As the temperature increases, those substances with very weak intermolecular forces become gases directly (in a process called sublimation, which will be discussed in Section 10.2 "Phase Transitions: Melting, Boiling, and Subliming"). Substances with weak interactions can become liquids as the temperature increases. As the temperature increases even more, the individual particles will have so much energy that the intermolecular forces are overcome, so the particles separate from each other, and the substance becomes a gas (assuming that their chemical bonds are not so weak that the compound decomposes from the high temperature). Although is it difficult to predict the temperature ranges for which solid, liquid, or gas is the preferred phase for any random substance, all substances progress from solid to liquid to gas in that order as temperature increases.	validation	sciq	null
What pigment do slow fibers contain?	[ "melolin", "myoglobin", "hemoglobin", "iron" ]	B	Which of the following statements is true? a. Fast fibers have a small diameter. Fast fibers contain loosely packed myofibrils. Fast fibers have large glycogen reserves. Fast fibers have many mitochondria. Which of the following statements is false? a. Slow fibers have a small network of capillaries. Slow fibers contain the pigment myoglobin. Slow fibers contain a large number of mitochondria. Slow fibers contract for extended periods. Cardiac muscles differ from skeletal muscles in that they ________. are striated b. utilize aerobic metabolism.	validation	sciq	null

Who proposed the theory of evolution by natural selection?

[ "darwin", "Scopes", "Linnaeus", "shaw" ]

A

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Each specific polypeptide has a unique linear sequence of which acids?

[ "hydrochloric", "lactic", "amino", "fatty" ]

C

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A frameshift mutation is a deletion or insertion of one or more of what that changes the reading frame of the base sequence?

[ "proteins", "nucleotides", "genes", "carotenoids" ]

B

A frameshift mutation is a deletion or insertion of one or more nucleotides that changes the reading frame of the base sequence. Deletions remove nucleotides, and insertions add nucleotides. Consider the following sequence of bases in RNA:.

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What is an area of land called that is wet for all or part of the year?

[ "wetland", "grassland", "plains", "tundra" ]

A

A wetland is an area that is wet for all or part of the year. Wetlands are home to certain types of plants.

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Surface waters are heated by the radiation from?

[ "the moon", "gamma rays", "decomposition", "the sun" ]

D

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What are arteries, veins, and capillaries examples of?

[ "muscles", "organs", "blood vessels", "tissue" ]

C

Blood vessels include arteries, veins, and capillaries.

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Biochemical reactions of metabolism include what two general categories?

[ "catabolic and anabolic", "innumerable and anabolic", "discrete and telltale", "telltale and anabolic" ]

A

Biochemical reactions of metabolism can be divided into two general categories: catabolic reactions and anabolic reactions. You can watch an animation showing how the two categories of reactions are related at this URL: http://classes. midlandstech. edu/carterp/courses/bio225/chap05/lecture1. htm.

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Compounds with aluminum and silicon are commonly found in the clay fractions of soils derived from what?

[ "mineral ash", "volcanic ash", "volatile ash", "ground ash" ]

B

Compounds with aluminum and silicon are commonly found in the clay fractions of soils derived from volcanic ash. One of these compounds is vermiculite, which is formed in reactions caused by exposure to weather. Vermiculite has the following formula: Ca0.7[Si6.6Al1.4]Al4O20(OH)4. (The content of calcium, silicon, and aluminum are not shown as integers because the relative amounts of these elements vary from sample to sample. ) What is the mass percent of each element in this sample of vermiculite?.

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What organ has four major regions: the cerebrum, the diencephalon, the stem, and the cerebellum?

[ "heart", "liver", "lungs", "brain" ]

D

13.2 | The Central Nervous System By the end of this section, you will be able to: • Name the major regions of the adult brain • Describe the connections between the cerebrum and brain stem through the diencephalon, and from those regions into the spinal cord • Recognize the complex connections within the subcortical structures of the basal nuclei • Explain the arrangement of gray and white matter in the spinal cord The brain and the spinal cord are the central nervous system, and they represent the main organs of the nervous system. The spinal cord is a single structure, whereas the adult brain is described in terms of four major regions: the cerebrum, the diencephalon, the brain stem, and the cerebellum. A person’s conscious experiences are based on neural activity in the brain. The regulation of homeostasis is governed by a specialized region in the brain. The coordination of reflexes depends on the integration of sensory and motor pathways in the spinal cord.

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What can refer to a rope in a particular shape and a genetic structure involved in splicing?

[ "noose", "tourniquet", "braid", "lariat" ]

D

A lariat can refer to a rope in the form of a lasso. But it is also a genetic structure involved in splicing.

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What is the ratio of the mass of an object to its volume?

[ "diameter", "frequency", "median", "density" ]

D

Density is the ratio of the mass of an object to its volume.

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What is the most common type of anemia?

[ "vitamin d - def", "calcium - def", "vitamin k - def", "iron-def" ]

D

Anemia may not have any symptoms. Some people with anemia feel weak or tired in general or during exercise. They also may have poor concentration. People with more severe anemia often get short of breath during times of activity. Iron-deficiency anemia is the most common type of anemia. It occurs when the body does not receive enough iron. Since there is not enough iron, hemoglobin, which needs iron to bind oxygen, cannot function properly.

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What stimulates milk production in mammals?

[ "prolactin", "estrogen", "testosterone", "neurotoxin" ]

A

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During telophase , the chromosomes begin to uncoil and form what?

[ "nucleus", "mucosa", "chromatin", "mitochondria" ]

C

During telophase , the chromosomes begin to uncoil and form chromatin. This prepares the genetic material for directing the metabolic activities of the new cells. The spindle also breaks down, and new nuclear membranes form.

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The science dealing with the study of the atmosphere is known as what?

[ "meteorology", "geology", "cosmology", "climatology" ]

A

Meteorologists don’t study meteors—they study the atmosphere! The atmosphere is a thin layer of gas that surrounds Earth. The word “meteor” refers to things in the air. Meteorology includes the study of weather patterns, clouds, hurricanes, and tornadoes. Meteorology is very important. Using radars and satellites, meteorologists work to predict, or forecast, the weather ( Figure below ). Meteorologists are getting better at predicting the weather all the time. Meteorologists wonder how to better predict weather. They wonder what the effects of rising water vapor in the atmosphere will be on weather.

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On what basis are the eras of the phanerozoic eon separated?

[ "sparse extinctions", "mass birthings", "low birth rates", "mass extinctions" ]

D

The eras of the Phanerozoic Eon are separated by mass extinctions . During these events, large numbers of organisms became extinct very rapidly. There have been several extinctions in the Phanerozoic. Two mass extinctions stand out more than the others. One took place at the end of the Paleozoic. The other took place at the end of the Mesozoic.

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What type of response is generated when a stimulus is received by the nervous system?

[ "a action potential", "a motor response", "a sensory response", "a neural response" ]

B

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Fluid in the pseudocoelom serves as a hydrostatic what?

[ "vacuum", "shower", "skeleton", "cell membrane" ]

C

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How will global warming eliminate some islands and reduce the area of others?

[ "raise sea levels", "unafect sea levels", "lower sea levels", "affect sea levels" ]

A

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What is the term for the secretion of saliva?

[ "perspiration", "excretion", "salivation", "craving" ]

C

Regulation of Salivation The autonomic nervous system regulates salivation (the secretion of saliva). In the absence of food, parasympathetic stimulation keeps saliva flowing at just the right level for comfort as you speak, swallow, sleep, and generally go about life. Over-salivation can occur, for example, if you are stimulated by the smell of food, but that food is not available for you to eat. Drooling is an extreme instance of the overproduction of saliva. During times of stress, such as before speaking in public, sympathetic stimulation takes over, reducing salivation and producing the symptom of dry mouth often associated with anxiety. When you are dehydrated, salivation is reduced, causing the mouth to feel dry and prompting you to take action to quench your thirst. Salivation can be stimulated by the sight, smell, and taste of food. It can even be stimulated by thinking about food. You might notice whether reading about food and salivation right now has had any effect on your production of saliva. How does the salivation process work while you are eating? Food contains chemicals that stimulate taste receptors on the tongue, which send impulses to the superior and inferior salivatory nuclei in the brain stem. These two nuclei then send back parasympathetic impulses through fibers in the glossopharyngeal and facial nerves, which stimulate salivation. Even after you swallow food, salivation is increased to cleanse the mouth and to water down and neutralize any irritating chemical remnants, such as that hot sauce in your burrito. Most saliva is swallowed along with food and is reabsorbed, so that fluid is not lost.

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What is the most common sti in the u.s.?

[ "herpes", "syphilis", "chlamydia", "genital warts" ]

C

Chlamydia is the most common STI in the U. S. As shown in the graph in Figure below , females are much more likely than males to develop chlamydia. Like most STIs, rates of chlamydia are highest in teens and young adults.

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What plant structures are the main avenues by which water evaporates from the sporophyte?

[ "chloroplasts", "stomata", "chlorophyll", "veins" ]

B

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Decomposers break down dead organisms into nutrients and what?

[ "gases", "soil", "fluids", "tissues" ]

A

Decomposers break down dead organisms into nutrients and gases so that they can be used by other organisms.

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What is the term for the use of technology to treat genetic disorders or change organisms so they are more useful to people?

[ "biotechnology", "nanotechnology", "biology", "physiology" ]

A

Biotechnology is the use of technology to treat genetic disorders or change organisms so they are more useful to people. Methods include gene cloning. Applications include gene therapy and genetically modified food crops.

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What science specialty, with a set of like-named scientific laws, refers to the study of energy and energy transfer involving physical matter?

[ "geology", "thermodynamics", "chemistry", "meteorology" ]

B

6.3 | The Laws of Thermodynamics By the end of this section, you will be able to: • Discuss the concept of entropy • Explain the first and second laws of thermodynamics Thermodynamics refers to the study of energy and energy transfer involving physical matter. The matter and its environment relevant to a particular case of energy transfer are classified as a system, and everything outside of that system is called the surroundings. For instance, when heating a pot of water on the stove, the system includes the stove, the pot, and the water. Energy is transferred within the system (between the stove, pot, and water). There are two types of systems: open and closed. An open system is one in which energy can be transferred between the system and its surroundings. The stovetop system is open because heat can be lost into the air. A closed system is one that cannot transfer energy to its surroundings. Biological organisms are open systems. Energy is exchanged between them and their surroundings, as they consume energystoring molecules and release energy to the environment by doing work. Like all things in the physical world, energy is subject to the laws of physics. The laws of thermodynamics govern the transfer of energy in and among all systems in the universe.

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What type of tissue makes up the brain and the nerves that connect the brain to all parts of the body?

[ "benign tissue", "nervous tissue", "neurotransmitters", "peripheral tissue" ]

B

Nervous tissue is made up of neurons, or nerve cells, that carry electrical messages. Nervous tissue makes up the brain and the nerves that connect the brain to all parts of the body.

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Periodic refers to something that does what?

[ "fail", "dies", "falls", "repeat" ]

D

Mendeleev’s table of the elements is called a periodic table because of its repeating pattern. Anything that keeps repeating is referred to as periodic. Other examples of things that are periodic include the monthly phases of the moon and the daily cycle of night and day. The term period refers to the interval between repetitions. In a periodic table, the periods are the rows of the table. In Mendeleev’s table, each period contains eight elements, and then the pattern repeats in the next row.

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Blood is pumped from the heart, pushing open which valves?

[ "aortic and carotid", "pulmonary and respiratory", "pulmonary and aortic semilunar", "thoracic and aortic" ]

C

Ventricular Systole Ventricular systole (see Figure 19.27) follows the depolarization of the ventricles and is represented by the QRS complex in the ECG. It may be conveniently divided into two phases, lasting a total of 270 ms. At the end of atrial systole and just prior to atrial contraction, the ventricles contain approximately 130 mL blood in a resting adult in a standing position. This volume is known as the end diastolic volume (EDV) or preload. Initially, as the muscles in the ventricle contract, the pressure of the blood within the chamber rises, but it is not yet high enough to open the semilunar (pulmonary and aortic) valves and be ejected from the heart. However, blood pressure quickly rises above that of the atria that are now relaxed and in diastole. This increase in pressure causes blood to flow back toward the atria, closing the tricuspid and mitral valves. Since blood is not being ejected from the ventricles at this early stage, the volume of blood within the chamber remains constant. Consequently, this initial phase of ventricular systole is known as isovolumic contraction, also called isovolumetric contraction (see Figure 19.27). In the second phase of ventricular systole, the ventricular ejection phase, the contraction of the ventricular muscle has raised the pressure within the ventricle to the point that it is greater than the pressures in the pulmonary trunk and the aorta. Blood is pumped from the heart, pushing open the pulmonary and aortic semilunar valves. Pressure generated by the left ventricle will be appreciably greater than the pressure generated by the right ventricle, since the existing pressure in the aorta will be so much higher. Nevertheless, both ventricles pump the same amount of blood. This quantity is referred to as stroke volume. Stroke volume will normally be in the range of 70–80 mL. Since ventricular systole began with an EDV of approximately 130 mL of blood, this means that there is still 50–60 mL of blood remaining in the ventricle following contraction. This volume of blood is known as the end systolic volume (ESV).

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What term refers to a list of the elements that will replace the ones below them in single-replacement reactions?

[ "activity series", "growth series", "Up series", "probably series" ]

A

Chemical reactivity trends are easy to predict when replacing anions in simple ionic compounds—simply use their relative positions on the periodic table. However, when replacing the cations, the trends are not as straightforward. This is partly because there are so many elements that can form cations; an element in one column on the periodic table may replace another element nearby, or it may not. A list called the activity series does the same thing the periodic table does for halogens: it lists the elements that will replace elements below them in single-replacement reactions. A simple activity series is shown below.

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What cause many human diseases by killing host cells or disturbing their homeostasis?

[ "bacteria", "cancer", "parasites", "viruses" ]

D

Viruses cause many human diseases by killing host cells or disturbing their homeostasis. Viruses are not affected by antibiotics. Several viral diseases can be treated with antiviral drugs or prevented with vaccines.

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What two types of digestive systems do invertebrates have?

[ "slow or complete", "fast or slow", "incomplete or complete", "unstable or complete" ]

C

Invertebrates have one of two types of digestive system: an incomplete or complete digestive system. Both are shown in Figure below . An incomplete digestive system consists of a digestive cavity with one opening. The single opening serves as both mouth and anus. A complete digestive system consists of a digestive tract with two openings. One opening is the mouth. The other is the anus.

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What are ectothermic vertebrates that divide their time between freshwater and terrestrial habitats?

[ "amphibians", "arthropods", "mammals", "reptiles" ]

A

Amphibians are ectothermic vertebrates that divide their time between freshwater and terrestrial habitats.

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During exercise, the rate of blood returning to the heart does this?

[ "reduces", "remains stable", "increases", "changes randomly" ]

C

Correlation Between Heart Rates and Cardiac Output Initially, physiological conditions that cause HR to increase also trigger an increase in SV. During exercise, the rate of blood returning to the heart increases. However as the HR rises, there is less time spent in diastole and consequently less time for the ventricles to fill with blood. Even though there is less filling time, SV will initially remain high. However, as HR continues to increase, SV gradually decreases due to decreased filling time. CO will initially stabilize as the increasing HR compensates for the decreasing SV, but at very high rates, CO will eventually decrease as increasing rates are no longer able to compensate for the decreasing SV. Consider this phenomenon in a healthy young individual. Initially, as HR increases from resting to approximately 120 bpm, CO will rise. As HR increases from 120 to 160 bpm, CO remains stable, since the increase in rate is offset by decreasing ventricular filling time and, consequently, SV. As HR continues to rise above 160 bpm, CO actually decreases as SV falls faster than HR increases. So although aerobic exercises are critical to maintain the health of the heart, individuals are cautioned to monitor their HR to ensure they stay within the target heart rate range of between 120 and 160 bpm, so CO is maintained. The target HR is loosely defined as the range in which both the heart and lungs receive the maximum benefit from the aerobic workout and is dependent upon age.

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What is the pattern of spacing among individuals within the boundaries of the population?

[ "equilibrium", "dispersion", "diffusion", "frequency" ]

B

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What level is a feeding position in a food chain or web?

[ "singular", "trophic", "neural", "differentiation" ]

B

Each food chain or food web has organisms at different trophic levels. A trophic level is a feeding position in a food chain or web. The trophic levels are identified in the food web in Figure above . All food chains and webs have at least two or three trophic levels, but they rarely have more than four trophic levels. The trophic levels are:.

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What do most of the noble gas elements have in common?

[ "zero valence electrons", "eight valence electrons", "four valence electrons", "two valence electrons" ]

B

Atoms can join together by forming a chemical bond, which is a very strong attraction between two atoms. Chemical bonds are formed when electrons in different atoms interact with each other to make an arrangement that is more stable than when the atoms are apart. What causes atoms to make a chemical bond with other atoms, rather than remaining as individual atoms? A clue comes by considering the noble gas elements, the rightmost column of the periodic table. These elements—helium, neon, argon, krypton, xenon, and radon—do not form compounds very easily, which suggests that they are especially stable as lone atoms. What else do the noble gas elements have in common? Except for helium, they all have eight valence electrons. Chemists have concluded that atoms are especially stable if they have eight electrons in their outermost shell. This useful rule of thumb is called the octet rule, and it is a key to understanding why compounds form.

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What are the organisms that live in extreme conditions known as?

[ "fibroblasts", "extremophiles", "naturophiles", "carotenoids" ]

B

Many archaeans are extremophiles. Extremophiles are organisms that live in extreme conditions. For example, some archaeans live around hydrothermal vents. A hydrothermal vent is a crack on the ocean floor. You can see one in Figure below . Boiling hot, highly acidic water pours out of the vent. These extreme conditions don't deter archaeans. They have evolved adaptations for coping with them. These conditions are like those on ancient Earth. This suggests that archaeans may have evolved very early in Earth's history.

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Collision frequency is greater for what category of catalysts, which also tend to be more sensitive to temperature and more 'expensive'?

[ "analogous", "homogeneous", "heterogeneous", "contiguous" ]

B

Heterogeneous catalysts are easier to recover. Collision frequency is greater for homogeneous catalysts. Homogeneous catalysts are often more sensitive to temperature. Homogeneous catalysts are often more expensive. Saylor URL: http://www. saylor. org/books.

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What does the pull of the moon's gravity on earth cause?

[ "earthquakes", "storms", "tides", "waves" ]

C

Figure below shows why tides occur. The main cause of tides is the pull of the Moon’s gravity on Earth. The pull is greatest on whatever is closest to the Moon. Although the gravity pulls the land, only the water can move. As a result:.

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A water molecule forms when oxygen (o) and _______ atoms react and are held together by covalent bonds?

[ "nitrogen", "hydrogen (h)", "carbon", "steam" ]

B

An example of a chemical compound is water. A water molecule forms when oxygen (O) and hydrogen (H) atoms react and are held together by covalent bonds. Like other compounds, water always has the same chemical composition: a 2:1 ratio of hydrogen atoms to oxygen atoms. This is expressed in the chemical formula H 2 O. A model of a water molecule is shown in Figure below .

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What force makes objects seem lighter in water?

[ "buoyant", "resilient", "surface tension", "gravity" ]

A

Because of buoyant force, objects seem lighter in water. You may have noticed this when you went swimming and could easily pick up a friend or sibling under the water. Some of the person’s weight was countered by the buoyant force of the water.

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What is the process by which the nucleus of a eukaryotic cell divides?

[ "meiosis", "cytokinesis", "mitosis", "angiogenesis" ]

C

Mitosis is the process by which the nucleus of a eukaryotic cell divides. It happens in four phases: prophase, metaphase, anaphase, and telophase.

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Iceland is made up of a series of?

[ "glaciers", "volcanoes", "outcrops", "earthquakes" ]

B

A fissure eruption on a volcano in Iceland. The lava flows downhill and turns snow into steam. Iceland is made of a set of volcanoes that are the result of a hotspot that lies on a mid-ocean ridge. The island is the only location where the mid-ocean ridge can be seen above sea level. Icelandic volcanoes have made the news lately since some have shut down air traffic in parts of Europe.

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What type of organism does not need oxygen for growth and dies in its presence?

[ "aerobic", "symbiotic", "anaerobic", "acidic" ]

C

An anaerobic organism is any organism that does not need oxygen for growth and even dies in its presence. Obligate anaerobes will die when exposed to atmospheric levels of oxygen. Clostridium perfringens bacteria, which are commonly found in soil around the world, are obligate anaerobes. Infection of a wound by C. perfringens bacteria causes the disease gas gangrene. Obligate anaerobes use molecules other than oxygen as terminal electron acceptors.

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What is the name of specialized organs that filter the lymph by percolation through a maze of connective tissue filled with white blood cells?

[ "cochlea", "alveoli", "lymph nodes", "edema glands" ]

C

eventually diffuses back into the capillaries near the venules. The remaining 15% of blood plasma drains out from the interstitial fluid into nearby lymphatic vessels (Figure 40.18). The fluid in the lymph is similar in composition to the interstitial fluid. The lymph fluid passes through lymph nodes before it returns to the heart via the vena cava. Lymph nodes are specialized organs that filter the lymph by percolation through a maze of connective tissue filled with white blood cells. The white blood cells remove infectious agents, such as bacteria and viruses, to clean the lymph before it returns to the bloodstream. After it is cleaned, the lymph returns to the heart by the action of smooth muscle pumping, skeletal muscle action, and one-way valves joining the returning blood near the junction of the venae cavae entering the right atrium of the heart.

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What are hydrocarbons most important use?

[ "lightsource", "fuel", "electricity", "food" ]

B

Hydrocarbons have a wide variety of important uses, but their most important use is as fuels.

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What protects tissues of the central nervous system from changes in ph?

[ "sucrose ions", "bicarbonate ions", "fatty ions", "cerebrum" ]

B

Bicarbonate ions play an important role in neutralizing acids throughout the body. Bicarbonate ions are especially important for protecting tissues of the central nervous system from changes in pH. The central nervous system includes the brain, which is the body’s control center. If pH deviates too far from normal, the central nervous system cannot function properly. This can have a drastic effect on the rest of the body.

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The air pressure is about 80% that of ________ pressure at sea level.

[ "adverse atmospheric", "standard atmospheric", "internal atmospheric", "specific atmospheric" ]

B

The air pressure is about 80% that of standard atmospheric pressure at sea level. For significant figure purposes, the standard pressure of 760 mmHg has three significant figures.

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Vertebrates - including fish, amphibians, reptiles, birds, and mammals - belong to what phylum?

[ "nematota", "chordata", "animalia", "angulata" ]

B

Vertebrates are animals in Phylum Chordata. Modern vertebrates include fish, amphibians, reptiles, birds, and mammals. You can see examples of all these groups of vertebrates in Figure below .

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In our wildflower population, the pool of what remains constant from one generation to the next?

[ "genes", "genomes", "DNA", "eggs" ]

A

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When a membrane uses energy to move a substance across it, what kind of transport is this?

[ "fast", "inactive", "active", "slow" ]

C

x rms = 2Dt, where D is the diffusion constant, representative values of which are found in Table 12.2. • Osmosis is the transport of water through a semipermeable membrane from a region of high concentration to a region of low concentration. • Dialysis is the transport of any other molecule through a semipermeable membrane due to its concentration difference. • Both processes can be reversed by back pressure. • Active transport is a process in which a living membrane expends energy to move substances across it.

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An electrostatic attraction between two ions that have exchanged what?

[ "neutrons", "electrons", "quasars", "protons" ]

B

An electrostatic attraction between two ions that have exchanged electrons.

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During what part of a person's development are they generally at their physical peak?

[ "senility", "early adulthood", "late adulthood", "infancy" ]

B

Early adulthood starts at age 18 or 21. It continues until the mid-30s. During early adulthood, people are at their physical peak. They are also usually in good health. The ability to have children is greatest during early adulthood, as well. This is the stage of life when most people complete their education. They are likely to begin a career or take a full-time job. Many people also marry and start a family during early adulthood.

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What type of movement involves sluggish segmentation, primarily in the transverse and descending colons?

[ "haustral contraction", "gasutral contraction", "photoreactive contraction", "accompanying contraction" ]

A

Mechanical Digestion In the large intestine, mechanical digestion begins when chyme moves from the ileum into the cecum, an activity regulated by the ileocecal sphincter. Right after you eat, peristalsis in the ileum forces chyme into the cecum. When the cecum is distended with chyme, contractions of the ileocecal sphincter strengthen. Once chyme enters the cecum, colon movements begin. Mechanical digestion in the large intestine includes a combination of three types of movements. The presence of food residues in the colon stimulates a slow-moving haustral contraction. This type of movement involves sluggish segmentation, primarily in the transverse and descending colons. When a haustrum is distended with chyme, its muscle contracts, pushing the residue into the next haustrum. These contractions occur about every 30 minutes, and each last about 1 minute. These movements also mix the food residue, which helps the large intestine absorb water. The second type of movement is peristalsis, which, in the large intestine, is slower than in the more proximal portions of the alimentary canal. The third type is a mass movement. These strong waves start midway through the transverse colon and quickly force the contents toward the rectum. Mass movements usually occur three or four times per day, either while you eat or immediately afterward. Distension in the stomach and the breakdown products of digestion in the small intestine provoke the gastrocolic reflex, which increases motility, including mass movements, in the colon. Fiber in the diet both softens the stool and increases the power of colonic contractions, optimizing the activities of the colon.

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Vertebrates evolved from primitive forms of which creature?

[ "cephalopods", "gastropods", "chordates", "eukaryotes" ]

C

Vertebrates evolved from primitive chordates. This occurred about 550 million years ago. The earliest vertebrates may have been jawless fish, like the hagfish in Figure below . Vertebrates evolved a backbone to replace the notochord after the embryo stage. They also evolved a cranium, or bony skull, to enclose and protect the brain.

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What does the aqueous fluid between the chloroplast membrane and the grana known as?

[ "plasma", "water", "blood", "stroma" ]

D

Both chloroplasts and photosynthetic bacteria contain grana, neat stacks of flattened sac-shaped membrane compartments called thylakoids . Thylakoids can be considered a sub-organelle within the chloroplast. Between the chloroplast membrane and the grana is an aqueous fluid known as stroma . Thylakoids, especially the thylakoid membrane, organize patterns of proteins and other molecules which conduct photosynthesis, as shown in Figure below . In addition to enzymes, two basic types of molecules - pigments and electron carriers – are significant in this process. You can take a video tour of a chloroplast at Encyclopedia Britannica: Chloroplast : http://www. britannica. com/EBchecked/media/16440/Chloroplasts-circulate-within-plant-cells .

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When a hypothesis is repeatedly confirmed, what can it then become?

[ "study", "evolution", "theory", "Thesis" ]

C

When a hypothesis is confirmed repeatedly, it eventually becomes a theory – a general principle that is offered to explain natural phenomena. Note a key word – explanation. The theory offers a description of why something happens. A law, on the other hand, is a statement that is always true, but does not explain why. The law of gravity says a rock will fall when dropped, but does not explain why (gravitational theory is very complex and incomplete at present). The kinetic-molecular theory of gases, on the other hand, tells what happens when a gas is heated in a closed container (the pressure increases), but also explains why (the motions of the gas molecules are increased due to the change in temperature). Theories do not get “promoted” to laws because laws do not answer the “why” question.

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Using a hammer to remove a nail changes both the direction and strength of the what?

[ "applied force", "static energy", "gravity", "kinetic energy" ]

A

Using a hammer to remove a nail changes both the direction and strength of the applied force. Where is the fulcrum of the hammer when it is used in this way?.

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Through which process are plants able to make their own food?

[ "metabolism", "cell division", "glycolysis", "photosynthesis" ]

D

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What kind of waves are sound waves?

[ "spinning", "mechanical", "internal", "External" ]

B

A: It wouldn’t unless the vibrations were carried by another medium. Sound waves are mechanical waves, so they can travel only though matter and not through empty space.

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The protein without the prosthetic group is known as the what?

[ "spicule", "monoprotein", "xerophyte", "apoprotein" ]

D

As we will return to later, proteins are functional entities, composed of polypeptides and prosthetic group. The prosthetic group is essential for normal protein function. The protein without the prosthetic group is known as the apoprotein. biofundamentals – coreBIO.

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What connections allow heterocysts to transport fixed nitrogen to neighboring cells and to receive carbohydrates?

[ "neurons", "peptide", "heterogeneity", "intercellular" ]

D

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The classes anthozoa, scyphozoa, cubozoa, and hydrozoa make up what phylum?

[ "cnidaria", "mollusca", "crinoids", "poriferia" ]

A

differentiated cell types in each tissue layer, such as nerve cells, enzyme-secreting cells, and nutrient-absorbing cells, as well as intercellular connections between the cells. However, organs and organ systems are not present in this phylum. The nervous system is primitive, with nerve cells scattered across the body in a network. The function of the nerve cells is to carry signals from sensory cells and to contractile cells. Groups of cells in the nerve net form nerve cords that may be essential for more rapid transmission. Cnidarians perform extracellular digestion, with digestion completed by intracellular digestive processes. Food is taken into the gastrovascular cavity, enzymes are secreted into the cavity, and the cells lining the cavity absorb the nutrient products of the extracellular digestive process. The gastrovascular cavity has only one opening that serves as both a mouth and an anus (an incomplete digestive system). Like the sponges, Cnidarian cells exchange oxygen, carbon dioxide, and nitrogenous wastes by diffusion between cells in the epidermis and gastrodermis with water. Cnidarian Diversity The phylum Cnidaria contains about 10,000 described species divided into four classes: Anthozoa, Scyphozoa, Cubozoa, and Hydrozoa. The class Anthozoa includes all cnidarians that exhibit a sessile polyp body plan only; in other words, there is no medusa stage within their life cycle. Examples include sea anemones, sea pens, and corals, with an estimated number of 6,100 described species. Sea anemones are usually brightly colored and can attain a size of 1.8 to 10 cm in diameter. These animals are usually cylindrical in shape and are attached to a substrate. A mouth opening is surrounded by tentacles bearing cnidocytes (Figure 15.12).

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Where does waste enter the large intestine from?

[ "the small intestine", "kidneys", "the small tissue", "liver" ]

A

The large intestine is a wide tube that connects the small intestine with the anus. In adults, it is about five feet long. Waste enters the large intestine from the small intestine in a liquid state. As the waste moves through the large intestine, excess water is absorbed from it. After the excess water is absorbed, the remaining solid waste is called feces.

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What do different soil horizons show different amounts of?

[ "evolution", "alteration", "distortion", "secretion" ]

B

Soil horizons are layers within a soil. Different soil horizons show different amounts of alteration.

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What is the main source of energy for your body?

[ "vitamins", "proteins", "carbohydrates", "fats" ]

C

Carbohydrates, proteins, and lipids are categories of organic compounds. They give your body energy, though carbohydrates are the main source of energy. Proteins provide building materials, such as amino acids to build your own proteins. Proteins, vitamins, and minerals also help control body processes. Carbohydrates include sugars such as the glucose made by photosynthesis. Often glucose is stored in large molecules such as starch. Proteins are found in foods like meats and nuts. Lipids includes fats and oils. Though you should stay away from many types of fats, others are needed by your body. Important vitamins include vitamins A, B (multiple types) C, D, and E. Important minerals include calcium and potassium. What should you drink to get calcium? Milk is a good source.

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What are thin, very small tail-like projections that extend outward from the cell body that allow protists to move?

[ "cilia", "notochords", "fins", "antennae" ]

A

The ciliates are protists that move by using cilia. Cilia are thin, very small tail-like projections that extend outward from the cell body. Cilia beat back and forth, moving the protist along. Paramecium has cilia that propel it.

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Earthquakes, which may occur on california’s abundant faults, can also trigger what?

[ "Waves", "landslides", "avalanches", "floods" ]

B

Some communities have developed landslide warning systems. Around San Francisco Bay, the National Weather Service and the U. S. Geological Survey use rain gauges to monitor soil moisture. If soil becomes saturated, the weather service issues a warning. Earthquakes, which may occur on California’s abundant faults, can also trigger landslides.

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In which way do particles of water move in deep water?

[ "parabolas", "currents", "circles", "ellipses" ]

C

In deep water, particles of water just move in circles. They don’t actually move closer to shore with the energy of the waves. However, near the shore where the water is shallow, the waves behave differently. They start to drag on the bottom, creating friction (see Figure below ). The friction slows down the bottoms of the waves, while the tops of the waves keep moving at the same speed. This causes the waves to get steeper until they topple over and crash on the shore. The crashing waves carry water onto the shore as surf.

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What is the name of the study of heat engines?

[ "Chemical dynamics", "chemistry", "biology", "thermodynamics" ]

D

Thermodynamics is the study of heat engines. Any engine or power plant obeys the laws of thermodynamics. The first law of thermodynamics is a statement of conservation of energy. Total energy, including heat, is conserved in any process and in the complete cycle of a heat engine. The second law of thermodynamics as it applies to heat engines gives an absolute limit on the efficiency of any heat engine that goes through repetitious cycles.

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Mechanical waves can only trave through what?

[ "air", "light", "matter", "water" ]

C

The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium ( plural , media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid.

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If you examine eyeglasses for nearsighted people, you will find the lenses are thinnest in the center and of what shape?

[ "convex", "asymmetrical", "square", "concave" ]

D

Discussion The negative power indicates a diverging (or concave) lens, as expected. The spectacle produces a case 3 image closer to the eye, where the person can see it. If you examine eyeglasses for nearsighted people, you will find the lenses are thinnest in the center. Additionally, if you examine a prescription for eyeglasses for nearsighted people, you will find that the prescribed power is negative and given in units of diopters.

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What do you call air flowing over earth’s surface?

[ "gas", "air pressure", "steam", "wind" ]

D

Air always flows from an area of higher pressure to an area of lower pressure. Air flowing over Earth’s surface is called wind . The greater the difference in pressure, the stronger the wind blows.

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What three particles make up most atoms?

[ "protons, electrons and nucleus", "micrometres , electrons and neutrons", "neutrons, protons and radii", "protons, electrons and neutrons" ]

D

A neutron is one of three main particles that make up the atom. The other two particles are the proton and electron. Atoms of all elements—except for most atoms of hydrogen—have neutrons in their nucleus. The nucleus is the small, dense region at the center of an atom where protons are also found. Atoms generally have about the same number of neutrons as protons. For example, all carbon atoms have six protons and most also have six neutrons. A model of a carbon atom is shown in the Figure below . For an excellent video explaining the structure of atoms, including neutrons, go to this URL:.

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How can one dimensional vectors be added?

[ "exponentially", "incrementally", "sequentially", "arithmetically" ]

D

Vectors that are in one dimension can be added arithmetically.

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What is caused by the reaction of nonmetal oxides with water in the atmosphere?

[ "yellow rain", "acid rain", "ozone rain", "carbon rain" ]

B

Acid rain is caused by the reaction of nonmetal oxides with water in the atmosphere. One such reaction involves nitrogen dioxide (NO2) and produces nitric acid (HNO3): 3NO2 + H2O → 2HNO3 + NO If 1.82 × 1013 g of NO2 enter the atmosphere every year due to human activities, potentially how many grams of HNO3 can be produced annually?.

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Into how many basic regions can the aquatic biome be broken down?

[ "six", "two", "five", "One" ]

B

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The top of the saturated rock layer is called what?

[ "sand layer", "water table", "calcified layer", "compressed layer" ]

B

The top of the saturated rock layer above ( Figure above ) is called the water table . The water table isn’t like a real table. It doesn’t remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain, and it is lower when the weather is dry.

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Which field studies how to tailor medical treatments to our genetic profiles?

[ "metagenomics", "immunology", "pharmacogenomics", "proteomics" ]

C

We know that, thanks to our DNA, each of us is a little bit different. Some of those differences are obvious, like eye and hair color. Others are not so obvious, like how our bodies react to medication. Researchers are beginning to look at how to tailor medical treatments to our genetic profiles, in a relatively new field called pharmacogenomics . Some of the biggest breakthroughs have been in cancer treatment. For additional information on this “personalized medicine,” listen to http://www. kqed. org/quest/radio/personalized-medicine and see http://www. kqed. org/quest/blog/2009/09/11/reporters-notes-personalized-medicine/ .

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Research that focuses on understanding basic properties and processes without concern for the usefulness of this understanding is known as what kind of research?

[ "applied research", "pure research", "disconnected research", "focused research" ]

B

Pure research focuses on understanding basic properties and processes.

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Cells of what category of organisms can be organized at the level of cells, tissues, organs, and organ systems?

[ "multicellular", "biomolecular", "intricate", "complex" ]

A

Cells can exist independently as single-celled organisms or with other cells as multicellular organisms. Cells of a multicellular organism can be organized at the level of cells, tissues, organs, and organ systems.

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What property of materials describes the ease in which they can be molded into thin sheets?

[ "rigidity", "malleability", "plasticity", "permeability" ]

B

A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Silver is a shiny metal that conducts electricity very well. It can be molded into thin sheets, a property called malleability. Salt is dull and brittle and conducts electricity when it has been dissolved into water, which it does quite easily. Physical properties of matter include color, hardness, malleability, solubility, electrical conductivity, density, melting points , and boiling points .

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What do you call materials that have low resistance to electric current?

[ "electric conductors", "electromagnets", "poor conductors", "good insulator" ]

A

Materials that have low resistance to electric current are called electric conductors . Many metals—including copper, aluminum, and steel—are good conductors of electricity. The outer electrons of metal atoms are loosely bound and free to move, allowing electric current to flow. Water that has even a tiny amount of impurities is an electric conductor as well.

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What is the term for the transfer of heat by a current?

[ "radiation", "diffusion", "convection", "conduction" ]

C

Convection is the transfer of heat by a current. Convection happens in a liquid or a gas. Air near the ground is warmed by heat radiating from Earth's surface. The warm air is less dense, so it rises. As it rises, it cools. The cool air is dense, so it sinks to the surface. This creates a convection current ( Figure below ). Convection is the most important way that heat travels in the atmosphere.

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Arterioles receive blood from arteries, which are vessels with a much larger lumen. as their own lumen averages just 30 micrometers or less, arterioles are critical in slowing down—or resisting—blood flow. the arterioles can also constrict or dilate, which varies their what?

[ "resistance", "osmosis", "advantage", "gravity" ]

A

Chapter 20 1 Water. 3 A 5 C 7 C 9 A 11 D 13 B 15 A 17 C 19 A 21 C 23 D 25 D 27 C 28 Arterioles receive blood from arteries, which are vessels with a much larger lumen. As their own lumen averages just 30 micrometers or less, arterioles are critical in slowing down—or resisting—blood flow. The arterioles can also constrict or dilate, which varies their resistance, to help distribute blood flow to the tissues. 30 This is a venule. 32 People who stand upright all day and are inactive overall have very little skeletal muscle activity in the legs. Pooling of blood in the legs and feet is common. Venous return to the heart is reduced, a condition that in turn reduces cardiac output and therefore oxygenation of tissues throughout the body. This could at least partially account for the patient’s fatigue and shortness of breath, as well as her “spaced out” feeling, which commonly reflects reduced oxygen to the brain. 34 False. The plasma proteins suspended in blood cannot cross the semipermeable capillary cell membrane, and so they remain in the plasma within the vessel, where they account for the blood colloid osmotic pressure. 36 Nitric oxide is a very powerful local vasodilator that is important in the autoregulation of tissue perfusion. If it were not broken down very quickly after its release, blood flow to the region could exceed metabolic needs. 38 The gonadal veins drain the testes in males and the ovaries in females. 40 Angiogenesis inhibitors are drugs that inhibit the growth of new blood vessels. They can impede the growth of tumors by limiting their blood supply and therefore their access to gas and nutrient exchange.

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What is the circular center of a hurricane better known as?

[ "the nose", "the eye", "the epicenter", "the focus" ]

B

At the center of a hurricane is a small area where the air is calm and clear. This is called the eye of the hurricane ( Figure below ). The eye forms at the low-pressure center of the hurricane. Air in the eye rises upward.

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Are most glaciers currently growing or shrinking?

[ "growing", "shrinking", "freezing", "no change" ]

B

Glaciers are not static; they grow, they move and they shrink. Currently, most glaciers are shrinking.

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What kind of model - which includes producers, consumers and decomposers - shows the interactions between organisms across trophic levels?

[ "interdepence web", "organic web", "food web", "fuel web" ]

C

Figure 20.6 This food web shows the interactions between organisms across trophic levels. Arrows point from an organism that is consumed to the organism that consumes it. All the producers and consumers eventually become nourishment for the decomposers (fungi, mold, earthworms, and bacteria in the soil). (credit "fox": modification of work by Kevin Bacher, NPS; credit "owl": modification of work by John and Karen Hollingsworth, USFWS; credit "snake": modification of work by Steve Jurvetson; credit "robin": modification of work by Alan Vernon; credit "frog": modification of work by Alessandro Catenazzi; credit "spider": modification of work by "Sanba38"/Wikimedia Commons; credit "centipede": modification of work by “Bauerph”/Wikimedia Commons; credit "squirrel": modification of work by Dawn Huczek; credit "mouse": modification of work by NIGMS, NIH; credit "sparrow": modification of work by David Friel; credit "beetle": modification of work by Scott Bauer, USDA Agricultural Research Service; credit "mushrooms": modification of work by Chris Wee; credit "mold": modification of work by Dr. Lucille Georg, CDC; credit "earthworm": modification of work by Rob Hille; credit "bacteria": modification of work by Don Stalons, CDC).

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The multifidus muscle of the lumbar region helps extend and laterally flex this?

[ "vertebal column", "knee", "forearm", "pelvic muscle" ]

A

are associated. The semispinalis muscles include the semispinalis capitis, the semispinalis cervicis, and the semispinalis thoracis. The multifidus muscle of the lumbar region helps extend and laterally flex the vertebral column. Important in the stabilization of the vertebral column is the segmental muscle group, which includes the interspinales and intertransversarii muscles. These muscles bring together the spinous and transverse processes of each consecutive vertebra. Finally, the scalene muscles work together to flex, laterally flex, and rotate the head. They also contribute to deep inhalation. The scalene muscles include the anterior scalene muscle (anterior to the middle scalene), the middle scalene muscle (the longest, intermediate between the anterior and posterior scalenes), and the posterior scalene muscle (the smallest, posterior to the middle scalene).

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What does k stand for on the periodic table?

[ "magnesium", "aluminum", "potassium", "calcium" ]

C

Q: The table shown in the Figure above is called the periodic table of the elements. Each symbol stands for a different element. What do you think the symbol K stands for?.

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Beta decay occurs when a nucleus has too few of what relative to protons?

[ "protons", "nuclei", "electrons", "neutrons" ]

D

Beta decay occurs when a nucleus is unstable because it has too many or too few neutrons relative to protons. The nucleus emits a beta particle and energy. A beta particle is either an electron (beta-minus decay) or a positron (beta-plus decay).

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Trees have woody stems covered with what?

[ "larvae", "shells", "rust", "bark" ]

D

Trees have woody stems covered with bark.

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What prevents an object from moving in a straight line at a constant speed?

[ "friction", "force", "matter", "weight" ]

B

Newton’s first law implies that an object oscillating back and forth is experiencing forces. Without force, the object would move in a straight line at a constant speed rather than oscillate. Consider, for example, plucking a plastic ruler to the left as shown in Figure 16.2. The deformation of the ruler creates a force in the opposite direction, known as a restoring force. Once released, the restoring force causes the ruler to move back toward its stable equilibrium position, where the net force on it is zero. However, by the time the ruler gets there, it gains momentum and continues to move to the right, producing the opposite deformation. It is then forced to the left, back through equilibrium, and the process is repeated until dissipative forces dampen the motion. These forces remove mechanical energy from the system, gradually reducing the motion until the ruler comes to rest. The simplest oscillations occur when the restoring force is directly proportional to displacement. When stress and strain were covered in Newton’s Third Law of Motion, the name was given to this relationship between force and displacement was Hooke’s law:.

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The effect of acetylcholine in heart muscle is inhibitory rather than what?

[ "olfactory", "excitatory", "neurotransmitter", "exofactory" ]

B

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What is the division of the cytoplasm in eukaryotic cells?

[ "cytokinesis", "metamorphosis", "andronisis", "electrolysis" ]

A

The second major step is cytokinesis . As in prokaryotic cells, the cytoplasm must divide. Cytokinesis is the division of the cytoplasm in eukaryotic cells, resulting in two genetically identical daughter cells.

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The white of an egg becomes opaque when cooked because what are insoluble and solidify?

[ "fatty acids", "calcium molecules", "acetic proteins", "denatured proteins" ]

D

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What kind of plants lack xylem or phloem to transport nutrients, water, and food?

[ "trichina", "nonvascular", "single-celled", "spicule" ]

B

Nonvascular plants evolved first. They are distinct from the algae because they keep the embryo inside of the reproductive structure after fertilization. These plants do not have vascular tissue, xylem or phloem, to transport nutrients, water, and food. Examples include mosses, liverworts, and hornworts. Without vascular tissue, these plants do not grow very tall.

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Exemplified by baring teeth, what type of displays are common in the animal kingdom, and sometimes serve as a 'bluff'?

[ "aggressive", "passive", "defensive", "sexual" ]

A

incorrectly or a proper response is not given, the mating ritual is abandoned and the mating attempt will be unsuccessful. The mating display of the common stork is shown in Figure 45.37. Aggressive displays are also common in the animal kingdom. An example is when a dog bares its teeth when it wants another dog to back down. Presumably, these displays communicate not only the willingness of the animal to fight, but also its fighting ability. Although these displays do signal aggression on the part of the sender, it is thought that these displays are actually a mechanism to reduce the amount of actual fighting that occurs between members of the same species: they allow individuals to assess the fighting ability of their opponent and thus decide whether it is “worth the fight. ” The testing of certain hypotheses using game theory has led to the conclusion that some of these displays may overstate an animal’s actual fighting ability and are used to “bluff” the opponent. This type of interaction, even if “dishonest,” would be favored by natural selection if it is successful more times than not.

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The preferred phase a substance adopts can change with temperature. at low temperatures, most substances are solids (only helium is predicted to be a liquid at absolute zero). as the temperature increases, those substances with very weak intermolecular forces become gases directly in a process called this?

[ "sublimation", "vaporization", "Freezing Point", "speciation" ]

A

The preferred phase a substance adopts can change with temperature. At low temperatures, most substances are solids (only helium is predicted to be a liquid at absolute zero). As the temperature increases, those substances with very weak intermolecular forces become gases directly (in a process called sublimation, which will be discussed in Section 10.2 "Phase Transitions: Melting, Boiling, and Subliming"). Substances with weak interactions can become liquids as the temperature increases. As the temperature increases even more, the individual particles will have so much energy that the intermolecular forces are overcome, so the particles separate from each other, and the substance becomes a gas (assuming that their chemical bonds are not so weak that the compound decomposes from the high temperature). Although is it difficult to predict the temperature ranges for which solid, liquid, or gas is the preferred phase for any random substance, all substances progress from solid to liquid to gas in that order as temperature increases.

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What pigment do slow fibers contain?

[ "melolin", "myoglobin", "hemoglobin", "iron" ]

B

Which of the following statements is true? a. Fast fibers have a small diameter. Fast fibers contain loosely packed myofibrils. Fast fibers have large glycogen reserves. Fast fibers have many mitochondria. Which of the following statements is false? a. Slow fibers have a small network of capillaries. Slow fibers contain the pigment myoglobin. Slow fibers contain a large number of mitochondria. Slow fibers contract for extended periods. Cardiac muscles differ from skeletal muscles in that they ________. are striated b. utilize aerobic metabolism.

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