bio 122 exam 3
Muscles that contract slowly and use less ATP to generate their force contain primarily: small motor units. fast twitch fibers slow twitch fibers obtain their energy primarily through anaerobic glycolytic processes.
slow twitch fibers
True or false: In muscle tissue, protein consumed in the diet but not immediately used is stored as adipose tissue.
false
. Bile, which aids in the digestion of fat, is stored in the _____ .
gall bladder
Which of the following graphs best depicts the relationship between the amount of force (Y axis) produced by a muscle fiber and sarcomere length (X axis)? graph A graph B graph C graph D graph E
graph D
One of the most extensive animal radiations is that of terrestrial arthropods (includes insects). They excrete uric acid as their form of nitrogenous waste. Why does this allow them to conserve more water than a mammal with extensive kidney tubules for water reabsorption? The high solubility of uric acid allows the excretory system to reabsorb water. Uric acid levels stay high in the blood maintaining a strong osmotic gradient, which allows water to be reabsorbed. After precipitation, uric acid no longer influences osmolarity; water returns to the hypertonic tissues. After precipitation, uric acid no longer influences osmolarity; water leaves the hypertonic tissues.
After precipitation, uric acid no longer influences osmolarity; water returns to the hypertonic tissues.
True or false: A gram of elephant tissue has a higher resting metabolic rate than a gram of mouse tissue.
False
True or false: Marine fish have impermeable renal tubules, allowing them to reabsorb scarce electrolytes without also reabsorbing water they are trying to eliminate.
False
True or false: The loop of Henle represents a countercurrent exchanger because it creates a concentration gradient rather than simply maintaining it.
False
Freshwater fish are in a hypotonic environment. What keeps the cells in their body from lysing? Freshwater fish have chloride channels that actively move chloride out of the gills into the surrounding water, allowing water to move into the gills. Freshwater fish have chloride channels that actively move chloride out of the gills into the surrounding water, allowing water to move out of the gills. Freshwater fish have chloride channels that actively move chloride into the gills, allowing water to move into the gills. Freshwater fish have chloride channels that actively move chloride into the gills, allowing water to move out of the gills.
Freshwater fish have chloride channels that actively move chloride into the gills, allowing water to move into the gills.
A woman's husband is a Type I diabetic. He gives her a pen and tells her to inject him with its contents if he ever passes out due to low blood sugar. What hormone does this pen likely contain? Insulin Oxytocin Glucagon Glycogen
Glucagon
What is the significance of the fact that the loop of Henle extends into the medulla of the kidney with sections that run antiparallel to one another? It maintains the concentration gradient in the kidney. It generates the concentration gradient in the kidney. It contains more aquaporins. It is permeable to urea on one side, but not the other.
It generates the concentration gradient in the kidney.
Which of the following best describes the characteristics of the descending arm of the loop of Henle? (Select all that apply.) It is permeable to water. It actively transports electrolytes. It is impermeable to water. Its filtrate is mainly urea. Its filtrate becomes more and more concentrated.
It is permeable to water. Its filtrate becomes more and more concentrated.
You discover a new type of marine organism that has the kidneys of a fish but no gills. What affect would the absence of gills have on excretion of nitrogenous waste? No affect. Fish kidneys excrete all nitrogenous waste. Nitrogenous excretion decreases because no nitrogen uptake is occurring at the gills. Nitrogenous excretion increases at the kidneys because it cannot be lost at the gills. No affect. Nitrogenous wastes diffuse across the skin.
Nitrogenous excretion increases at the kidneys because it cannot be lost at the gills.
In the heart of a fish, where would you expect to find oxygenated blood? Choose all that apply. in the right atrium in the left atrium in the ventricle in a single atrium (fish only have one) Nowhere; oxygenated blood does not pass through a fish's heart.
Nowhere; oxygenated blood does not pass through a fish's heart.
_____________ hormones (like thyroid-stimulating hormone or TSH) signal organs of the endocrine system to secrete new, additional hormones.
Tropic
Depending on their environments, animals may lose electrolytes (select all that apply): across the gills. in sweat. in urine. in feces. across the skin.
across the gills. in sweat. in urine. in feces. across the skin.
Cross-bridges form between the contractile proteins of the muscle cell. The movement of cross-bridges shortens the muscle fiber. What two proteins participate in cross-bridge formation? actin and myosin troponin and titin titin and myosin titin and actin
actin and myosin
The organization of the vasa recta around the loop of Henle: allows urea to be concentrated in the distal convoluted tubule. allows water to be maximally reabsorbed from the distal convoluted tubule. allows the concentration gradient established by the loop of Henle to be maintained. allows urea to be concentrated in the distal convoluted tubule and allows the concentration gradient established by the loop of Henle to be maintained. allows water to be maximally reabsorbed from the distal convoluted tubule and allows the concentration gradient established by the loop of Henle to be maintained.
allows the concentration gradient established by the loop of Henle to be maintained.
Because ammonia is very toxic, it is kept at low levels in the body by (select all that apply): being eliminated. being converted to urea. being stored away from body tissues. being converted to uric acid. being converted to amino acids.
being eliminated. being converted to urea. being converted to uric acid.
Which of the following types of blood vessels would have the greatest resistance to flow? veins capillaries venules arteries arterioles
capillaries
In the glomerulus, blood is filtered under pressure through a filtration barrier made up of (select all that apply): capillary endothelial cells. a basal lamina. a layer of podocytes. renal corpuscles. loops of Henle.
capillary endothelial cells. a basal lamina. a layer of podocytes.
To counter the ingestion of excess salts, marine teleost fish have specialized cells in their gills that pump _____ ions into the surrounding seawater. As these ions leave the fishes' bodies, they create an electrical gradient that is balanced when _____ ions leave their bodies as well. chloride; sodium potassium; magnesium calcium; sodium sodium; chloride magnesium; potassium
chloride; sodium
What event results from the hydrolysis of ATP to ADP by the myosin head? cross-bridge formation shortening of the muscle fiber cocking of myosin head to its high-energy position the power stroke
cocking of myosin head to its high-energy position
In unicellular organisms and simple multicellular organisms, waste compounds are isolated in a cellular compartment called a _____ and are eliminated by exocytosis.
contractile vacuole
Calmodulin is involved in the regulation of: skeletal muscle contraction. propagation of a nerve impulse across a synapse. contraction of smooth muscle. propagation of heart muscle contraction to the entire myocardium.
contraction of smooth muscle.
Multicellular animals with pressurized circulatory systems use a three-step process to isolate and eliminate wastes. Arrange these steps in order from earliest to latest. filtration; reabsorption; secretion secretion; filtration; reabsorption filtration; secretion; reabsorption reabsorption; filtration, secretion secretion; reabsorption; filtration
filtration; reabsorption; secretion
Marine fish will (select all that apply): lose electrolytes across the skin and gills. gain water across the skin and gills. gain electrolytes across the skin and gills. gain electrolytes from drinking. lose water across the skin and gills.
gain electrolytes across the skin and gills. gain electrolytes from drinking. lose water across the skin and gills.
Uric acid produced by insect Malphigian tubules does not influence the movement of water from the hindgut because: it is eliminated by the tubules before water reaches the hindgut. it precipitates due to the low pH of the fluid in the rectum and therefore does not contribute to osmotic pressure. water moves only in response to the osmotic pressure created by proteins and sugars in the hindgut. uric acid is equally concentrated in the hindgut and in the body fluids. None of these choices are correct.
it precipitates due to the low pH of the fluid in the rectum and therefore does not contribute to osmotic pressure.
Most nutrient absorption takes place in the (select all correct choices): duodenum. jejunum. ileum. colon. appendix.
jejunum ileum.
In fish (select all that apply): nitrogenous waste excretion takes place through the gills. kidneys are primarily organs of water and electrolyte balance. kidneys are proportionally smaller than they are in mammals. kidneys are unsegmented. renal tubules are permeable to water regardless of the type of fish.
nitrogenous waste excretion takes place through the gills. kidneys are primarily organs of water and electrolyte balance.
Anaerobic metabolism (select all correct choices): occurs in the cytosol in the absence of oxygen. provides rapid, short-term energy. breaks glucose down into carbon dioxide. leads to the maximum possible yield of ATP in a cell. occurs in the mitochondria in the presence of oxygen.
occurs in the cytosol in the absence of oxygen. provides rapid, short-term energy.
ADH controls how diluted or concentrated urine is by controlling the: permeability of the collecting ducts to water. permeability of the collecting ducts to electrolytes. permeability of the collecting ducts to urea. permeability of the loops of Henle to water. permeability of the loops of Henle to electrolytes.
permeability of the collecting ducts to water.
The first part of the renal tubule is called the _____ and is specialized for _____. proximal convoluted tubule; reabsorption of electrolytes and other nutrients. loop of Henle; creation of a concentration gradient in the interstitial fluid distal convoluted tubule; secretion of additional wastes into the urine distal convoluted tubule; reabsorption of water collecting duct; reabsorption of water
proximal convoluted tubule; reabsorption of electrolytes and other nutrients.
. True or false: Kidneys are well-adapted for osmoregulation because they receive a large fraction of the blood leaving the heart at each heartbeat.
true
Increase the cross-sectional area of the flexor true false
true
Move the attachment point of the flexor on skeletal element #1 towards the load true false
true
Muscles can produce forces when shortening and when lengthening. true false
true
True or false: Despite being an osmoconformer, a shark still spends energy to regulate the concentrations of individual ions such as potassium, chloride, and sodium.
true
You measure levels of Ca2+ in various locations within a motor neuron and a skeletal muscle fiber when the motor neuron is not depolarized, and the muscle fiber is at rest. Where do you expect to find high levels of Ca2+ ? in vesicles within the motor neuron. in the cytosol of the motor neuron terminus. in the synaptic cleft binding to the receptors at the motor endplate of the muscle cell. Diffusing into the motor neuron through specialized channels in the plasma membrane. within the t-tubules. within the sarcoplasmic reticulum of the muscle fiber. h.bound to troponin bound to tropomyosin bound to myosin
within the sarcoplasmic reticulum of the muscle fiber.
Aldosterone is a hormone secreted by the adrenal cortex, and insulin is a peptide secreted by the pancreas. When aldosterone contacts a target cell, it binds to an intracellular receptor and migrates to the nucleus; insulin binds to extracellular receptors on the plasma membrane. What is the most likely reason for this difference? Aldosterone is hydrophilic and therefore must enter the aqueous environment of the cytoplasm to have an effect. Aldosterone is lipid-soluble and therefore easily crosses the phospholipid bilayer of the plasma membrane. Aldosterone is too small to bind extracellular receptors on the plasma membrane. Insulin is too large to interact with DNA.
Aldosterone is lipid-soluble and therefore easily crosses the phospholipid bilayer of the plasma membrane.
Which of the following statements is true regarding neurotransmitters and synaptic signaling? (Select all that apply.) All neurotransmitters are also hormones. All synaptic signaling is rapid. All synaptic signaling occurs between nerve cells. All neurotransmitters are released into the bloodstream.
All synaptic signaling is rapid.
The pit viper Bothrops jararaca makes a venom that was used as an arrowhead poison by indigenous tribes of Brazil. This venom inhibits the enzyme necessary to activate angiotensin. Angiotensin is a naturally-occurring peptide hormone that causes vasoconstriction and thirst. Why would a molecule that inhibits the activation of a natural vasoconstrictor be poisonous? An inhibitor of angiotensin may cause a fatal drop in blood pressure. An inhibitor of angiotensin may allow blood pressure to rise too high, causing stroke. An inhibitor of angiotensin may prevent adrenaline surges. An inhibitor of angiotensin may paralyze prey. An inhibitor of angiotensin may stimulate the parasympathetic nervous system.
An inhibitor of angiotensin may cause a fatal drop in blood pressure.
A lioness begins her nightly hunt after spending the day beneath a tree in the Serengeti. What happens to the blood vessels in her body as she goes from resting to hunting? Arterioles supplying her stomach and intestines contract. Arterioles supplying her stomach and intestines expand. Arterioles supplying her limb muscles contract. Arterioles supplying her limb muscles expand.
Arterioles supplying her stomach and intestines contract. Arterioles supplying her limb muscles expand.
We breathe more quickly and deeply when we exercise. Why does this make sense? (Select all the correct answer options.) Because when we exercise we consume more CO2 and must increase ventilation to supply the CO2. Because when we exercise, we use more ATP, and additional O2 is necessary to generate sufficient ATP. Because when we exercise, we hydrolyze more ATP to ADP and Pi, and O2 is necessary for the hydrolysis, so we increase our intake of oxygen. Because when we exercise, we produce more CO2 ¬ and increased ventilation is necessary to rid ourselves of CO2.
Because when we exercise, we use more ATP, and additional O2 is necessary to generate sufficient ATP. Because when we exercise, we produce more CO2 ¬ and increased ventilation is necessary to rid ourselves of CO2.
Which of the following accurately describe(s) ectotherms compared to endotherms of similar size at similar body temperatures? (Select all correct choices.) Ectotherm metabolic rates are about 25% those of endotherms. Ectotherms cannot sustain prolonged activity for as long as endotherms can. Ectotherms can survive much longer periods without food than can endotherms. Ectotherm metabolic rates decrease as body temperature increases. Ectotherms never reach activity levels of endotherms.
Ectotherm metabolic rates are about 25% those of endotherms. Ectotherms cannot sustain prolonged activity for as long as endotherms can. Ectotherms can survive much longer periods without food than can endotherms.
Given what you have learned about metabolic rates in endotherms and ectotherms, which of the following can you infer? Ectotherms can be active for much longer periods than endotherms. Endotherms have a higher density of mitochondria than ectotherms. Ectotherms have an overall higher metabolic rate than endotherms. An endotherm requires less food than an ectotherm of the same size.
Endotherms have a higher density of mitochondria than ectotherms.
A molecule of the fatty acid palmitic acid yields approximately 106 molecules of ATP. How is this possible if fatty acids are not substrates for glycolysis? Fatty acid oxidation produces the electron carriers FADH2 and NADH as well as molecules of acetyl CoA, all of which directly or indirectly provide substrates for the electron transport chain. Fatty acids directly donate their electrons to the electron transport chain. Palmitic acid is first converted to glucose in order to begin the sequence of steps necessary for oxidative phosphorylation. Palmitic acid produces ATP by substrate-level phosphorylation, and therefore does not need to go through the steps of glycolysis, acetyl-CoA synthesis, the citric acid cycle, or the electron transport chain.
Fatty acid oxidation produces the electron carriers FADH2 and NADH as well as molecules of acetyl CoA, all of which directly or indirectly provide substrates for the electron transport chain.
Copepods are a group of small invertebrates found in both marine and freshwater habitats. In 1963, Anraku and Omori published a paper on the relationship between the feeding habits of different species of copepods and the structure of their mouth-parts. Which of the following would be a logical expectation in such a study? Herbivorous copepods have mandibles (lower jaws) whose cutting edges are provided with very sharp teeth. Herbivorous copepods have mandibles (lower jaws) whose cutting edges are provided with grinding teeth. Herbivorous copepods have no need for jaws because they do not catch prey. Herbivorous copepods should have jaws with slender teeth to cut through vegetation.
Herbivorous copepods have mandibles (lower jaws) whose cutting edges are provided with grinding teeth.
Given the properties of myoglobin shown in the O2 saturation curve to the right, what advantage does myoglobin confer to contracting muscles? It pumps oxygen from hemoglobin in order to bind oxygen. It contributes to the dark color of flight muscle in birds. It increases the effectiveness of glycolytic muscles used in short bursts. It releases bound oxygen at lower pO2 conditions than hemoglobin does. It binds oxygen at pO2 values at which hemoglobin is releasing its bound O2.
It binds oxygen at pO2 values at which hemoglobin is releasing its bound O2.
Which of the following statements is true regarding the pituitary gland? (Select all that apply.) It is composed of two glands. It serves as a "control center" for the endocrine system. It produces hormones that can target the kidneys. It receives information from the hypothalamus. It could be considered part of the nervous system.
It is composed of two glands. It serves as a "control center" for the endocrine system. It produces hormones that can target the kidneys. It receives information from the hypothalamus. It could be considered part of the nervous system.
Sensors in the medullary respiratory center detect changes in blood pH. If the pH drops, the respiratory center increases the rate of ventilation. Why does this make sense? Actually it doesn't make sense. There is no relationship between pH and ventilation rate. It makes sense because CO2 is formed from O2, and therefore CO2 is a sign that oxygen is being consumed. It makes sense because tissues that are more actively working produce more CO2, and when CO2 mixes with water, it becomes an acid and lowers the pH. It makes sense because hemoglobin carries CO2 and therefore blocks oxygen binding to the heme site, creating an oxygen deficiency.
It makes sense because tissues that are more actively working produce more CO2, and when CO2 mixes with water, it becomes an acid and lowers the pH.
Honeybee workers spend their first few weeks as young adults tending the colony's brood, then later shift jobs to foraging for food outside the colony. When researchers fed the young bees candy spiked with the molecule ethyl oleate, the young bees continued to babysit and delayed the job shift to foraging. What would it require to demonstrate that ethyl oleate normally acts as a pheromone, not as an endocrine or paracrine signal? It would require demonstration that ethyl oleate binds to a receptor and initiates a series of responses. It would require demonstration that ethyl oleate is released by another individual of the same species. It would require demonstration that ethyl oleate is released by a predator and causes a behavioral change in the prey.
It would require demonstration that ethyl oleate is released by another individual of the same species.
If water passed over the gills of fish in the same direction as blood flow through the capillaries in lamellae, how would gas exchange be affected? Select all correct choices. More oxygen would diffuse from the water into the fish's bloodstream. Less oxygen would diffuse from the water into the fish's bloodstream. More carbon dioxide would diffuse out of the fish's bloodstream into the water. Less carbon dioxide would diffuse out of the fish's bloodstream into the water. Gas exchange would remain the same, regardless of the direction of water flow.
Less oxygen would diffuse from the water into the fish's bloodstream. Less carbon dioxide would diffuse out of the fish's bloodstream into the water.
Rattlesnakes contract their tail shaker muscles at frequencies up to 90 Hertz (90 times a second) to create their rattling sound; they move their body muscles much more slowly (about 5 Hertz) to slither around. Do you expect the tail shaker muscles to produce more, the same, or less force per unit cross-sectional area than the body muscles? Why? More, because there is a positive relationship between contraction speed and force production. The same, because there is no relationship between contraction speed and force production. Less, because there is a negative relationship between contraction speed and force production. Less, because there is a positive relationship between contraction speed and force production. More information is needed, because there is no generalized relationship between contraction speed and force production.
Less, because there is a negative relationship between contraction speed and force production.
The most common approach used to measure metabolic rate is to measure the rate of O2 consumption. Although there are small errors inherent in this method, it is easy, and provides a good estimate of metabolic rate. Why is the rate of oxygen consumption an appropriate measure of metabolic rate? Metabolic rate is the amount of energy used per unit time. The production of usable energy in the form of ATP depends largely on aerobic respiration. Metabolic rate is the amount of energy used per unit time. The hydrolysis of ATP to ADP and Pi is an aerobic process. Metabolic rate is the amount of energy released in anabolic processes, and anabolic processes are aerobic.
Metabolic rate is the amount of energy used per unit time. The production of usable energy in the form of ATP depends largely on aerobic respiration.
Which of the following statements is true regarding respiration in birds? Choose all that apply. Bird lungs inflate due to negative pressure in the chest cavity. Bird lungs deflate due to negative pressure in the chest cavity. Oxygen enters the bloodstream via crosscurrent exchange. Oxygen enters the bloodstream via countercurrent exchange. Respiration depends on the movement of air through air sacs. Respiration depends on the movement of air through spiracles.
Oxygen enters the bloodstream via crosscurrent exchange. Respiration depends on the movement of air through air sacs.
Rabbits produce two types of droppings: fecal pellets, which are waste products of digestion, and cecotropes, which they re-ingest. Ruminants do not re-ingest any feces. What is the difference between the two that requires re-ingestion by rabbits, not cows? Ruminants use microorganisms to digest cellulose, rabbits secrete cellulose-digesting enzymes. Rabbits use microorganisms to digest cellulose, ruminants secrete cellulose-digesting enzymes. Rabbits are hindgut fermenters, so nutrients would be lost if the products of fermentation in the cecum were not eaten; ruminants are foregut fermenters, and the products of digestion are absorbed in the small intestine. Rabbits consume a carnivorous diet and ruminants a cellulose-based diet, and their digestive systems are adaptations to these two dietary specializations.
Rabbits are hindgut fermenters, so nutrients would be lost if the products of fermentation in the cecum were not eaten; ruminants are foregut fermenters, and the products of digestion are absorbed in the small intestine.
Walking along a beach, you find a vertebra from a fish. Unlike whale vertebra, the mature bone of this fish species lacks osteocytes. In other words, the mature bone is acellular. This is true of many fish species. How do you think the lack of cells would affect bone function? The bone would probably not develop properly without cells. The bone would probably not be able to repair itself if injury occurred without the osteoblasts to secrete bone material. The bone would probably be much more heavily mineralized because the space that the cells normally occupy would be mineralized instead. The bone would probably be much more brittle because the presence of cells keeps bone flexible. The bone would probably be "floppy" because the presence of cells makes the bone stiff.
The bone would probably not be able to repair itself if injury occurred without the osteoblasts to secrete bone material.
A mammalian fetus possesses a mutation that causes it to only synthesize adult hemoglobin. How will this mutation affect the fetus? Select all correct choices. The fetus will derive more oxygen from its mother's bloodstream. The fetus will derive less oxygen from its mother's bloodstream. The fetus will derive the same amount of oxygen from its mother's bloodstream as if it produced fetal hemoglobin. The fetus will not derive oxygen from its mother's bloodstream, as oxygen is provided by the amniotic fluid. The fetus will not derive oxygen from its mother's bloodstream, as the blood of the fetus does not come into contact with maternal blood.
The fetus will derive less oxygen from its mother's bloodstream.
What would happen if you placed a trout (freshwater fish) into a saltwater tank at the aquarium and made some observations? The fish would take on water quickly and get bloated. The fish would lose water and look wrinkled. The fish would take on water initially, but could reverse the direction of Cl- ion movement to deal with excess water. The fish would lose water initially, but could reverse the direction of Cl- ion movement to deal with excess water.
The fish would take on water quickly and get bloated.
A researcher is studying several different Rhodnius mutants. One of her mutants only molts normally up until the second nymph stage. After that, insects continue to molt but keep demonstrating body plans of the second nymph stage. What is the likely effect of this mutation in Rhodnius? (Select all that apply.) The juvenile hormone is not expressed. The ecdysone hormone is not expressed. The prothoracicotropic hormone (PTTH) is not expressed. The juvenile hormone is overexpressed. The ecdysone hormone is overexpressed. The prothoracicotropic hormone (PTTH) is overexpressed.
The juvenile hormone is overexpressed.
Imagine that during her hunt, the same lioness wounds a gazelle. The gazelle is able to escape, but its blood pressure is rapidly decreasing as it loses blood. What can happen in the gazelle's body to increase blood pressure? The pituitary gland can secrete vasopressin. The peripheral nervous system can signal specific arterioles to contract. The peripheral nervous system can signal specific arterioles to expand. The pituitary gland can secrete thyroid stimulating hormone (TSH).
The pituitary gland can secrete vasopressin. The peripheral nervous system can signal specific arterioles to contract.
Curare is a poison that was used by South American Indians on their arrowheads. Curare blocks the action of the neurotransmitter acetylcholine. How did the action of curare make hunting easier for these Indians? Blocking acetylcholine shut down cellular respiration and killed organisms. The prey were paralyzed. The hunted animals bled to death. Curare interferes with the spontaneous depolarization of heart muscle cells.
The prey were paralyzed.
What happens when action potentials stimulate a muscle at a rate that does not allow relaxation between contractions? The strength of contraction decreases with subsequent stimuli. The strength of contraction increases with subsequent stimuli. The strength of contraction does not change. More motor units are recruited.
The strength of contraction increases with subsequent stimuli.
You reach down to pick up a bucket full of water. When you begin your arm is straight and once you have lifted the bucket your arm is bent (forearm touching your biceps). As you are picking up the bucket of water, you stop when your humerus and ulna are at a ninety-degree angle, thereby holding the bucket in the same place. At that point, which of the following statements are false? Select all answer options that are false. There is an increase in recruitment of motor units for contraction. Sarcomere length continues to shorten the longer you hold onto the bucket. Ca2+ is bound to troponin. The force generated by the muscle increases with time (i.e., the longer you hold the bucket the more force is generated). The force generated by the muscle stays the same. Your biceps is exerting a smaller force than your triceps.
There is an increase in recruitment of motor units for contraction. Sarcomere length continues to shorten the longer you hold onto the bucket. The force generated by the muscle increases with time (i.e., the longer you hold the bucket the more force is generated). Your biceps is exerting a smaller force than your triceps.
Pyrrhocoris apterus, or firebug, is native to Europe and China, and eats the seeds of lime trees and mallow trees. What is the most likely explanation for the fact that a native North American species, the fir tree, synthesizes a compound that disrupts development of this European insect? The fir tree benefits from this compound because its effect on the firebug decreases competition for resources in its natural environment. The fir tree benefits from this compound because its effect on the firebug increases the survival of fir tree offspring. The fir tree benefits from this compound because its effect on the firebug increases predation pressure on its competition. The fir tree benefits from this compound because its effect on the firebug increases the survival of other, related members of the same species. There is likely strong similarity in the hormone receptors of different insects so that a compound made by a tree native to North America has an effect on an insect native to Europe.
There is likely strong similarity in the hormone receptors of different insects so that a compound made by a tree native to North America has an effect on an insect native to Europe.
Which of the following represent limitations on a cheetah's ability to be an effective predator? (Select all correct choices.) They must rest for long periods between sprints. They cannot run when the temperature reaches around 105oF. They cannot successfully prey on goats, which can release excess heat as they run. They lose incredible amounts of heat during a sprint, causing their muscles to tighten after a short period of time. They have a top speed significantly lower than that of most of their desired prey.
They must rest for long periods between sprints. They cannot run when the temperature reaches around 105oF.
Walking along a beach, you find a section of an adult grey whale's vertebral column with three vertebra. Which of the following are characteristics of these huge bones? They were formed by intramembranous ossification; they contain osteoblasts when they are fully formed. They were formed by endochondral ossification; they do not contain osteoblasts when they are fully formed. They were formed by intramembranous ossification; they contain chondocytes when they are fully formed. They were formed by endochondral ossification; they do not contain chondrocytes when they are fully formed.
They were formed by endochondral ossification; they do not contain chondrocytes when they are fully formed.
When a skeletal muscle contracts, what is happening at the level of the muscle proteins? Thick filaments shorten. Thin filaments slide relative to thick filaments. Thin filaments depolymerize to shorten. Calcium ions bind to tropomyosin, which allows actin to bind to myosin. Tropomyosin binds to troponin, which allows calcium to bind to actin.
Thin filaments slide relative to thick filaments.
The term "empty calorie" is sometimes used in dietary terminology to denote food lacking in vitamins, minerals, dietary fiber, etc. This terminology makes sense because a calorie unaccompanied by vitamins is not useful as a source of energy. This terminology makes sense because a calorie may be empty or full depending on whether it comes from a carbohydrate, protein or fat. This terminology is misleading because a calorie is a measure of energy, and a calorie has a defined energy content. This terminology is misleading because a calorie is the amount of energy necessary to raise the temperature of 1 gram of water by 1° C, which is irrelevant to living things.
This terminology is misleading because a calorie is a measure of energy, and a calorie has a defined energy content.
2. What is the function of tropomyosin in muscle cells? a. Tropomyosin binds to actin molecules and brings about shortening of the muscles. b. Tropomyosin covers the myosin binding sites on the actin molecules, preventing contraction from occurring. c. Tropomyosin is the contractile unit of the muscle cell. d. Tropomyosin stores calcium.
Tropomyosin covers the myosin binding sites on the actin molecules, preventing contraction from occurring.
You reach down to pick up a bucket full of water. When you begin your arm is straight and once you have lifted the bucket your arm is bent (forearm touching your bicep). As you begin to pick up the bucket, which of the following have occurred? Select all correct answer options. Troponin is no longer bound to actin. Ca2+ increases in the sarcoplasmic reticulum. Acetylcholinesterase is active at the motor end plate. Myosin heads are attached to actin filaments. Ca2+ binds to myosin The distance between Z-lines stays the same The T-tubules are depolarized.
Troponin is no longer bound to actin. Ca2+ increases in the sarcoplasmic reticulum. Acetylcholinesterase is active at the motor end plate. Myosin heads are attached to actin filaments.
You compare the contraction frequency of rattlesnake tail muscles at 20oC and 35oC. Do you expect to see an effect of temperature on contraction frequency in this experiment? Why or why not? No, because protein structure is not affected by temperature. No, because neither of these temperatures are seen in the natural environment of a rattlesnake. Maybe, it would depend on whether the snakes are male or female. Yes, because muscle contraction is an enzymatic process, and thus will be temperature-dependent. Yes, because all biological structures show changes when the temperature changes from 20oC to 35oC.
Yes, because muscle contraction is an enzymatic process, and thus will be temperature-dependent.
At the doctor's office, you may have noticed that when you are asked to "breathe deeply," your chest rises and falls more dramatically than when you are breathing normally. Why? Your intercostal muscles are being used to expand your chest cavity. Your spiracles are being used to expand your chest cavity. Your air sacs are being used to expand your chest cavity. Your bronchioles are being used to expand your chest cavity.
Your intercostal muscles are being used to expand your chest cavity.
What factors cause oxygen to be released from hemoglobin? Select all correct choices. a change in the acidity or pH of blood an increase in CO2 in the bloodstream the formation of lactic acid by muscles an increase in aerobic respiration
a change in the acidity or pH of blood an increase in CO2 in the bloodstream the formation of lactic acid by muscles an increase in aerobic respiration
Which of the following is NOT a specialized function of one or more regions of the digestive tract? food storage aerobic metabolism chemical breakdown absorption of nutrients elimination of waste products
aerobic metabolism
You are literally running late to class. After your initial panic, though, you realized that you can make it on time at your regular jogging pace. You've been jogging for a few minutes and have a few minutes left before you arrive. At this point, how are your muscles providing themselves with energy? anaerobic glycolysis aerobic glycolysis lactic acid fermentation aerobic respiration oxidative fermentation
aerobic respiration
Muscle groups that produce similar motion, or work synergistically, are known as: agonists. antagonists. synergists. pro-agonists.
agonists.
An evolutionary advantage of the endoskeleton is that it (choose all correct answer options): allows growth of fairly large organisms. protects vital internal organs. provides a structure on which muscles can pull for an organism to move. makes the process of reproduction more efficient.
allows growth of fairly large organisms. protects vital internal organs. provides a structure on which muscles can pull for an organism to move.
Which of the following correctly lists the three forms of nitrogenous waste in order from least energetically expensive to produce to most energetically expensive to produce? uric acid, urea, ammonia uric acid, ammonia, urea urea, uric acid, ammonia ammonia, uric acid, urea ammonia, urea, uric acid
ammonia, urea, uric acid
Which of the following correctly lists the three forms of nitrogenous waste in order from the one that requires the most water to eliminate it to the one that requires the least water to eliminate it? uric acid, urea, ammonia uric acid, ammonia, urea urea, uric acid, ammonia ammonia, uric acid, urea ammonia, urea, uric acid
ammonia, urea, uric acid
Limbs like arms, legs, and the fins of whales are part of the: axial skeleton. appendicular skeleton. mobile skeleton. central skeleton.
appendicular skeleton.
During heavy exercise, the PO2 in muscle may drop to 20 mm Hg. Considering the oxygen-hemoglobin dissociation curve to the right, what is the approximate percent O2 saturation of hemoglobin in venous blood returning from skeletal muscles during heavy exercise? approximately100% approximately 75 % approximately 50 % approximately 20 % nearly 0 %
approximately 20 %
A new hormone is discovered that appears to play a role in bone development. The hormone is hydrophilic and composed of several amino acid chains. How should this hormone be classified? (Select all that apply.) as a steroid hormone as a peptide hormone as an amine hormone as a pheromone
as a peptide hormone
Much of the fluid that moves across capillary walls and into the tissues moves as a result of filtration, forced by blood pressure. O2 on the other hand travels from the capillaries into the tissues: because of a concentration gradient between O2 in the tissues and O2 in the blood. because of high CO2 concentration in the tissues, created as a by-product of cellular respiration. because osmotic pressure causes a net flow of O2 from the tissues into the blood. because it is pumped into the tissues where it is needed.
because of a concentration gradient between O2 in the tissues and O2 in the blood.
A beekeeper opens one of his hives. At first, only one bee gets under his suit and stings him. He is then swarmed by the rest of his bees, and ends up with several stings. Why did most of the hive attack him? Select all that apply. because the first bee produced alarm pheromones because the first bee produced trail pheromones because the first bee produced amine hormones because the first bee produced steroid hormones because the first bee produced paracrine signals
because the first bee produced alarm pheromones
None of the changes in the answer options will increase the load capacity of the flexor. true false
false
Kisspeptin is a protein that in humans has an important role in initiating secretion of the releasing factor gonadotropin-releasing hormone (GnRH). Endocrinologists are finding that the protein kisspeptin and its receptor are central to sexual maturation at puberty. Neurons that release kisspeptin carry estrogen receptors. If this is a negative feedback system, high levels of estrogen would be expected to: decrease kisspeptin synthesis. increase kisspeptin synthesis. neither increase nor decrease kisspeptin synthesis because steroid hormones do not affect protein synthesis.
decrease kisspeptin synthesis.
The red curve to the right shows O2 saturation in normal conditions and the blue curve to the right shows O2 saturation in someone with carbon monoxide poisoning. You can determine from this curve that carbon monoxide: decreases the amount of O2 in the air. decreases the amount of hemoglobin. decreases the binding of O2 to hemoglobin.
decreases the binding of O2 to hemoglobin.
One of the effects of the hormone secretin is to stimulate the release of bicarbonate ions into the duodenum, which neutralizes the acid that enters the duodenum with the chyme from the stomach. One consequence of neutralizing the pH in the intestine is that: carbohydrates are not as easily broken down in this neutral environment. enzymes that catalyze the hydrolysis of carbohydrates are denatured. enzymes that catalyze the hydrolysis of carbohydrates are active. the enzymatically catalyzed hydrolysis of carbohydrate that began in the stomach is halted in the duodenum.
enzymes that catalyze the hydrolysis of carbohydrates are active.
Essential amino acids must be supplied in the diet because: essential amino acids are the only ones that can be oxidized when necessary for ATP synthesis and cellular respiration. essential amino acids are necessary for protein biosynthesis, but we do not have the biochemical pathways to synthesize those amino acids. proteins cannot be synthesized without amino acids therefore all amino acids are essential.
essential amino acids are necessary for protein biosynthesis, but we do not have the biochemical pathways to synthesize those amino acids.
3. The contractile machinery of muscles is only found in the most recently diverged animal groups. A. true B. false
false
If a muscle contracts, all of the muscle fibers within that muscle must be contracting. true false
false
Increase the cross-sectional area of the extensor true false
false
Increase the thickness of skeletal element #1 true false
false
Increase the thickness of skeletal element #2 true false
false
Move the attachment point of the flexor on skeletal element #1 towards the joint true false
false
Move the attachment point of the flexor on skeletal element #2 towards the bottom of the element true false
false
Move the attachment point of the flexor on skeletal element #2 towards the top of the element true false
false
Muscles do not produce any force unless they are shortening or lengthening. true false
false
Because most herbivores do not produce cellulase, they have specialized compartments in their digestive tracts that (select all correct choices): provide appropriate temperature and pH for breaking down plant material. house large populations of bacteria and other single-celled symbionts that do produce cellulase. grind up the plant material using muscular gizzards or other structures. secrete alternative enzymes that carry out the same function as cellulase. ferment nutrients in the hindgut.
house large populations of bacteria and other single-celled symbionts that do produce cellulase.
In the heart of a reptile or amphibian, where would you expect to find oxygenated blood? Select all correct choices. in the right atrium in the left atrium mixed with de-oxygenated blood in a common ventricle mixed with de-oxygenated blood in the right ventricle Nowhere; oxygenated blood does not travel through the heart of these animals.
in the left atrium mixed with de-oxygenated blood in a common ventricle
Depending on their environments, animals may lose water (select all that apply): in urine and feces. through their lungs. by sweating. through their gills. during cellular respiration.
in urine and feces. through their lungs. by sweating. through their gills.
The midgut (select all correct choices): includes the small intestine. includes the large intestine. is where most nutrient absorption occurs. is where the highest concentration of amylase would be found. is where glucose is allowed to passively diffuse into cells.
includes the small intestine. is where most nutrient absorption occurs.
A woman visits a doctor. After hearing her symptoms and running some blood work, the doctor determines that she has an underactive pineal gland. What were her likely symptoms? insomnia (due to low melatonin levels) muscle soreness and inflammation (due to low cortisol levels) increased urination (due to high glucose levels) constipation (due to low gastrin levels)
insomnia (due to low melatonin levels)
Hydrostatic elements of vertebrates that have bony endoskeletons include: the cytoskeletal proteins present in individual cells. intervertebral disks. the ligaments that reinforce joints. the keratinized outer covering.
intervertebral disks.
Usain Bolt, a world champion sprinter, can run a 10 m split in 0.82 second. Say you obtain a quadriceps muscle sample from Usain Bolt and compare it to one from a 25 year old male of average physical fitness. What differences do you expect to observe between those two muscle samples? Select all correct answer options. more fast-twitch fibers in Usain Bolt's muscle more mitochondria in Usain Bolt's muscle red and white muscle fibers of larger cross-sectional area in Usain Bolt's muscle
more fast-twitch fibers in Usain Bolt's muscle more mitochondria in Usain Bolt's muscle red and white muscle fibers of larger cross-sectional area in Usain Bolt's muscle
The microvilli of the cells lining the small intestine secrete enzymes that break disaccharides (like lactose) into their subunits, which can be absorbed. Most adults in the world stop producing the enzyme lactase after early childhood and thus are "lactose intolerant". Those who do continue to digest lactose in adulthood are termed "lactose tolerant". Lactose tolerance originally arose by mutation, and is associated with one of several autosomal dominant alleles. It is likely that the mutations conferring lactose tolerance are: mutations in regulatory DNA of the lactase-coding gene. mutations within the protein coding sequence of the gene. gene duplications.
mutations in regulatory DNA of the lactase-coding gene.
Suction feeding (select all correct choices): is the most generalized form of prey capture among fish. involves the rapid expansion of the fish's oral cavity. allows its users to be "sit and wait" predators. is used by aquatic salamanders as well as fish. can be used by some insects and young mammals.
s the most generalized form of prey capture among fish. involves the rapid expansion of the fish's oral cavity. allows its users to be "sit and wait" predators. is used by aquatic salamanders as well as fish. can be used by some insects and young mammals.
A researcher is studying the function of a peptide hormone in rabbits and humans. She notices that this hormone has a different effect in these two mammals, despite the hormone receptor having the same sequence (and structure) in both animals. What accounts for this difference in hormone function? sequence differences in the peptide hormone itself sequence differences in components of the associated second messenger pathway sequence differences in the hormone's target genes sequence differences in cholesterol
sequence differences in components of the associated second messenger pathway sequence differences in the hormone's target genes
1. Striated muscles appear striated or banded under a microscope. Striated muscle fibers include (Choose all correct answer options): a. skeletal muscle b. muscles of cnidarians c. smooth muscle cells d. cardiac muscle cells
skeletal muscle cardiac muscle cells
Which layer of the digestive tract houses the blood and lymph vessels into which nutrients are transported? lumen mucosa submucosa longitudinal muscles serosa
submucosa
The shaft of a long bone is also known as: the diaphysis. the epiphysis. trabeculae. the long bone wall.
the diaphysis.
The fact that in certain populations (in northern Europe and east Africa) adults continue to digest lactose suggests that: the mutation that allowed continued production of lactase in adults conferred a selective advantage in cultures where domesticated animals supplied milk . when some individuals saw the others able to drink milk they realized the advantage and made the change also. drinking milk into adulthood causes a genetic change in a person's lactase gene. because the mutation conferring lactose tolerance is dominant, it is by definition the most common allele.
the mutation that allowed continued production of lactase in adults conferred a selective advantage in cultures where domesticated animals supplied milk .
Consider the positive feedback regulating mammalian childbirth. In this process, the pituitary gland is _________, oxytocin is __________, and a uterine contraction is __________. the sensor; the effector; both the stimulus and response the effector; the sensor; both the stimulus and response both the stimulus and response; the effector; the sensor both the stimulus and response; the sensor; the effector
the sensor; the effector; both the stimulus and response
Which of the following is the motor endplate? the terminal membrane of the motor neuron where neurotransmitter is released the portion of the membrane of the muscle cell that has receptors that respond to the neurotransmitter released by the motor neuron. the membrane of the sarcoplasmic reticulum where calcium is stored the Z disc where two sarcomeres adjoin
the terminal membrane of the motor neuron where neurotransmitter is released
Tendons function: to attach muscle to bone. to attach two separate bones. as the site of bone growth. as an organic component of bone.
to attach muscle to bone.
It takes very few molecules of a hormone to cause changes in a target cell. This may be explained by the fact that (select all that apply): transcriptional activation produces many copies of mRNA, each of which is translated many times. the mechanism of hormonal action involves the replication of the hormone within the target cell to quickly magnify the hormone's effect. hormones are large molecules that persist for years and can repeatedly stimulate the same cell. the mechanism of hormonal action may involve an enzyme cascade that amplifies the response to a hormone. the mechanism of hormonal action involves memory cells that have had prior contact with the hormone and immediately respond to its presence.
transcriptional activation produces many copies of mRNA, each of which is translated many times. the mechanism of hormonal action may involve an enzyme cascade that amplifies the response to a hormone.
E. coli resides in our small and large intestines and, in the process of nourishing itself by digesting the "leftovers" it finds in our digestive tracts, provides us with (select all correct choices): essential amino acids. vitamin K. essential fatty acids. minerals such as zinc and iron. vitamin D.
vitamin K.