Which of the following best describes double fertilization in flowering plants?two sperms are needed to fertilize the eggflowers must be pollinated twice to yield both fruits and seedsone sperm fertilizes the egg, and a second sperm fertilizes both polar nucleithe egg of the embryo sac is diploid

one sperm fertilizes the egg, and a second sperm fertilizes both polar nuclei

Part completeEcdysozoans, which includes pirapulids (worm-like worms), tardigrades (water bears), onycophorans (velvet worms), and arthropods (crustaceans, insects, and arachnids), share which defining characteristic?trochophore larval stageciliated mouth partslobed finsregular molting of skin

regular molting of skin

Which of the following is necessary for a generative cell in a pollen grain to produce two sperm cells?a single mitotic divisiona single meiotic divisiontwo mitotic divisionstwo meiotic divisions

a single mitotic division

Part completeWe evolved from which clade of fish?chondrichthyans, cartilaginous fishcyclostomes, hagfish and lampreyactinopterygians, ray-finned fishsarcopterygians, lobe-finned fish

sarcopterygians, lobe-finned fish

Following meiosis in a typical dicot ovule, a single surviving megaspore divides how many times and how many nuclei are ultimately produced?3 divisions; 12 nuclei2 divisions; 6 nuclei4 divisions; 16 nuclei3 divisions; 8 nuclei

3 divisions; 8 nuclei

What tissue lines most exchange surfaces of multicellular animals?connective tissuesmooth muscleepithelial tissueneural tissue

epithelial tissue

Which type of muscle directly helps move food along the digestive tract?skeletal musclestriated musclecardiac musclesmooth muscle

smooth muscle

Which of the following is a triploblastic organism that contians a mesodermal tissue layer during development?coraljellyfishseastarsea anenome

seastar

Which of these provides the best advantage for an animal that conforms to a changing environmental condition, such as temperature?The animal's internal temperature changes opposite to the change in the external temperature.The animal spends less energy regulating its internal temperature.The animal is more likely to sleep during the day.The animal spends more time looking for food.

The animal spends less energy regulating its internal temperature

Use the model of circulation in the leg of a Canada goose to answer the following question.

Which of the following is the best interpretation of the model?that arterial blood is always cooler in the abdomen, compared to the temperature of the venous blood in the feet of the goosethat warmer arterial blood can bypass the legs as needed, when the legs are too cold to function wellthat warmer arterial blood transfers heat to the cooler venous bloodthat warmer venous blood transfers heat to the cooler arterial blood

that warmer arterial blood transfers heat to the cooler venous blood

The panting responses observed in overheated birds and mammals dissipate heat loss by what process?evaporationvasoconstrictionacclimationcountercurrent exchange

evaporation

Which of the following animals uses the largest percentage of its energy budget for homeostatic regulation?marine jelly (an invertebrate)desert insectsnake in a temperate forestdesert bird

desert bird

A researcher is setting up an experiment to measure basal metabolic rate in prairie voles (Microtus ochrogaster–a small rodent). Which of the following would be the best set of conditions for the voles immediately before and during the measurement?

OptionHousing ConditionMeasurement ConditionAa cage with plenty of food and water to avoid stressa warmer room than the room where housedBa cage with plenty of food and water to avoid stressa room the same temperature as the room where housedCa cage with no food for a few hours before measurementa colder room than the room where housedDa cage with no food for a few hours before measurementa room the same temperature as the room where housed

D

Consider the energy budgets for a human, an elephant, a penguin, a mouse, and a snake. The __________ would have the highest total annual energy expenditure, and the __________ would have the highest energy expenditure per unit mass.mouse; snakeelephant; humanpenguin; mouseelephant; mouse

lephant; mouse

t is important for pregnant women to consume folic acid supplements because ________.folic acid deprivation is a cause of heart abnormalities in a newbornthe fetus stores folic acid in high quantitiesfolic acid deprivation is associated with neural tube defects in a fetusthe fetus is not able to acquire oxygen by breathing on its own

folic acid deprivation is associated with neural tube defects in a fetus

The essential nutrients for proper human nutrition include __________.cellulosecalcium, sodium, potassium, and other mineralsglucoseall of the amino acidsactive enzymes from plants and⁄or animals

calcium, sodium, potassium, and other minerals

An example of a filter feeder would be a:fiddler crabbaleen whalegreat white sharkseastar

baleen whale

A ___________, such as a fig wasp, may live its entire life on it's own food source.bulk feederfilter feedersubstrate feedersuction feeder

substrate feeder

Which of the following organisms is most likely to have the highest total annual energy expenditure per unit mass?horseelephantmousehuman

mouse

Why do elephants most likely explore caves?in search of salt, an essential mineral nutrientin search of essential amino acids found in bat guanoin search of the haunted cave gourd, which contains essential fatty acids found no where elsebecause it is spooky

in search of salt, an essential mineral nutrient

Which animal taxon practices intracellular digestion of food that is ingested through the process of phagocytosis?anenomeslobstersspongescoral

sponges

If a person travels to a time zone that was several hours ahead of their own, they may experience tiredness known as jet lag. Jet lag is due to a disruption of ________.circadian rhythmnerve impulseshomeostasisbody temperature

circadian rhythm

You are studying a large tropical reptile that has a high and relatively stable body temperature. Which of the following observations is best for determining if the animal is an endotherm or an ectotherm?You know that it is an ectotherm because it is not a bird or mammal.You know from its high and stable body temperature that it must be an endotherm.You subject this reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with the ambient temperature. You conclude that it is an ectotherm.You note that its environment has a high and stable temperature. Because its body temperature matches the environmental temperature, you conclude that it is an ectotherm.

You subject this reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with the ambient temperature. You conclude that it is an ectotherm.

Why do vampire bats, which are primarily fluid feeders, practice reciprocal altruism with their roost mates, sharing blood meals with other bats without any immediate benefits?Because fluid is a necessarily messy meal, some bats accidentally spilled their blood meals into other bats mouths in their roosts. This lead to other vampire bats ravenously consuming each other, cannablistically. As a compromise, evolutionarily speaking, this species as evolved deliberate blood sharing to placate these killer tendencies.Bats are small mammals, thus have exceptionally low metabolic rates. This means that bats rarely have the energy to forage, and thus primarily rely on blood meal sharing between roost mates in order to survive. Reciprocal sharing leads to mutual benefits for all bats that participate, evolutionarily speaking. Bats are small mammals, thus have exceptionally high metabolic rates, particularly during flight. Because fluid is limited calorically and blood meals are hard to come by, these bats can only survive if they have roost-mates willing to share blood regularly. Reciprocal sharing leads to mutual benefits for all bats that participate, evolutionarily speaking. Bats are small mammals, thus have exceptionally low metabolic rates. Once they feed, they are satiated for months. Thus, bats usually have excess blood in their stomach, making it easier to share blood with other bats that haven't foraged recently. As vampires, they are immortal, and are not subject to evolution, negating the paradox of reciprocal altruism with selfish natural selection.

Bats are small mammals, thus have exceptionally high metabolic rates, particularly during flight. Because fluid is limited calorically and blood meals are hard to come by, these bats can only survive if they have roost-mates willing to share blood regularly. Reciprocal sharing leads to mutual benefits for all bats that participate, evolutionarily speaking.

Bats and hummingbirds are examples of __________.endotherms that are also poikilothermsendotherms that are also ectothermsectotherms that are also poikilothermsectotherms that are also homeothermsendotherms that are also homeotherms

endotherms that are also poikilotherms

In a cool environment, an ectotherm is more likely to survive an extended period of food deprivation than would an equally sized endotherm because the ectotherm ________.expends more energy per kilogram of body mass than does the endotherminvests little energy in temperature regulationhas greater insulation on its body surfacemaintains a higher basal metabolic rate

invests little energy in temperature regulation

Which of the following organisms is most likely to have the highest total annual energy expenditure?horseelephantmousehuman

elephant

Lysine is an essential amino acid for animals. An animal that lacked lysine in its diet ________.would be very healthywould make lysine from other amino acidscould not synthesize phospholipidscould not make many necessary proteins

could not make many necessary proteins

Elephants can often be observed using their trunks to spray water over their bodies, which cools them. What type of heat exchange does this process promote?radiationconvectionevaporationconduction

evaporation

The velocity of blood flow lowest in capillaries because ________.the systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventriclethe total cross-sectional area is greater in the capillaries than in any other part of the circulatory systemthe capillaries have internal valves that slow the flow of bloodthe diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate

the total cross-sectional area is greater in the capillaries than in any other part of the circulatory system

Suppose an organism had a mutation in the thrombin gene such that the thrombin protein was nonfunctional. Which of the following is the most likely impact that the mutation would have on this organism?The organism would not be able to produce new erythrocytes.The organism's blood would not clot effectively.The organism would not be able to exchange gases as well.The organism's immune system would be weakened.

The organism's blood would not clot effectively.

Which of the following happens to the production of insulin and glucagon in a healthy person after eating a carbohydrate-rich meal?insulin levels decrease and glucagon levels increaseinsulin levels increase and glucagon levels decreaseinsulin levels decrease and glucagon levels decreaseinsulin levels increase and glucagon levels increase

insulin levels increase and glucagon levels decrease

Atrial systole ________.occurs at the same time as ventricular diastolepumps blood to the aortaonly occurs in the left heart chambersrefers to the relaxation of the cardiac muscle

occurs at the same time as ventricular diastole

Which group of animals are characterized by having a relatively long cecum?omnivorescarnivoresherbivoresautotrophs

herbivores

Damage to the SA node in humans is most likely to result in a ________.negative effect on peripheral resistancedisruption on the rate and timing of cardiac muscle contractionsdirect effect on blood pressure monitors in the aortablockage of conductance between the bundle branches and the Purkinje fibers

disruption on the rate and timing of cardiac muscle contractions

Which of the following statements correctly describes peristalsis?It triggers voluntary control of the urethral sphincters regulating urination.It is a process of fat emulsification in the small intestine.It results from smooth muscle contractions that move food along the esophagus.It causes the transport of nutrients to the liver through the hepatic portal vessel.

It results from smooth muscle contractions that move food along the esophagus.

After surgical removal of the gallbladder, a person might need to limit his or her dietary intake ofstarch.sugar.fat.protein.

fat.

Which of the following would be the consequence if the direction of water flow over the gills of a fish was reversed, moving water inward past the operculum, past the gills, then out the mouth?the efficiency of gas exchange would increasethe thickness of the blood would decreasethe efficiency of gas exchange would be reducedthe thickness of the blood would increase

the efficiency of gas exchange would be reduced

Which statement best describes why cells of the digestive system secrete proteolytic enzymes, such as pepsin, in their inactive forms?By secreting inactive enzymes, the catalytic activity of the enzymes is maintained for a longer time.The stomach is too acidic to maintain these enzymes in their active form.Inactive pepsin and trypsin are more easily transported across the cell membraneThese proteolytic enzymes, in active form, would digest the very tissues that synthesize them.

These proteolytic enzymes, in active form, would digest the very tissues that synthesize them.

Which of the following are the only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart?mammalsreptilesamphibiansfishes

fishes

In which digestive system organ does nearly all nutrient absorption occur?large intestinepancreassmall intestinestomach

small intestine

Which statement best explains how the absorption of fats differ from that of carbohydrates?fat absorption primarily occurs in the stomach, whereas carbohydrates are absorbed from the small intestinemost absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the bloodcarbohydrates need to be emulsified before they can be digested, whereas fats do notfats, but not carbohydrates, are digested by bacteria before absorption

most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood

Which of the following is the correct sequence of blood flow in birds and mammals?left ventricle →→ aorta →→ lungs →→ systemic circulationvena cava →→ right atrium →→ right ventricle →→ pulmonary veinpulmonary vein →→ left atrium →→ left ventricle →→ pulmonary circuitvena cava →→ right atrium →→ right ventricle →→ pulmonary artery

vena cava →→ right atrium →→ right ventricle →→ pulmonary artery

In which organ does almost all enzymatic digestion of food occur?pancreasstomachsmall intestinelarge intestine

small intestine

Which of the following results in the greatest blood pressure in the mammalian aorta?diastole of the right atriumdiastole of the right ventriclesystole of the left ventriclesystole of the left atrium

systole of the left ventricle

Which of the following statements is true regarding the digestive system in mammals?the epiglottis prevents swallowed food from entering the tracheaall types of foods begin their enzymatic digestion in the esophagusafter leaving the oral cavity, the bolus enters the larynxthe trachea leads to the esophagus and then to the stomach

the epiglottis prevents swallowed food from entering the trachea

Birds acheive unidirectional flow through their lungs by:forcing air into the lungs through positive pressure, then expelling air from the sides of the body wall through spiracles attached to a tracheal systempulling air into posterior air sacs, forcing air through the lungs, and then allowing the air to expell out of the anuspulling air into anterior air sacs, then forcing that air through the lungs and into posterior air sacs, which then expell air back through the trachea and out of the mouthpulling air into posterior air sacs, then forcing that air through the lungs and into anterior air sacs, which then expell air back through the trachea and out of the mouth

pulling air into posterior air sacs, then forcing that air through the lungs and into anterior air sacs, which then expell air back through the trachea and out of the mouth

Which process does the large surface area in the intestine make more efficient?secretionfiltrationtemperature regulationabsorption

absorption

If there is a strong genetic link for type II diabetes mellitus in your family, which option might you take to minimize your risk of developing the disorder?monitor your blood glucose levels dailymaintain a healthy weight, eat a balanced diet, and exercisetake oral insulin dailyeat complex carbohydrates like starch instead of sweets

maintain a healthy weight, eat a balanced diet, and exercise

Which of the following would an organism need to adjust blood pressure independently in the blood vessels of the gas-exchange surface and in the blood vessels of the general body circulation?open circulatory systemfour-chambered hearthemocoeltwo-chambered heart

four-chambered heart

Which type of circulatory system is most likely present in organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells?an open circulatory systema gastrovascular cavitya closed circulatory systembranched tracheae

a closed circulatory system

Part completeAnimals cannot produce enzymes to digest cellulose, yet many termite species consume cellulose from plant material as a main part of their diet. How do termites access the nutrients contained in cellulose?Termites have specialized mouthparts to mechanically break down the cellulose.Cellulose is digested intracellularly in the termite hindgut.The ingested plant material also contains enzymes for cellulose digestion.Mutualistic bacteria in the hindgut of the termite digest the cellulose into sugars.

Mutualistic bacteria in the hindgut of the termite digest the cellulose into sugars.

Which of the following statements correctly compares respiration in fish and in mammals?The respiratory medium for fish carries more oxygen than the respiratory medium of mammals.The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.A countercurrent exchange mechanism between the respiratory medium and blood flow is seen in mammals but not in fish.In blood, oxygen is primarily transported by plasma in fish, but by red blood cells in mammals.

The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.

Which of the following are molecules on mammalian cells that recognize macromolecules that are present in or on certain groups of pathogens?interferonstoll-like receptorscomplement proteinscytokines

toll-like receptors

Which of the following cells and signaling molecules are involved in the initial stages of the inflammatory response?phagocytes and cytokinesdendritic cells and interferonsmast cells and histamineslymphocytes and interferons

mast cells and histamines

Which statement is true about innate immunity?The extent of an innate immunity response depends on an infected animal's previous exposure to a pathogenInnate immunity is the first, and most general, mechanism of protection against pathogens.Only vertebrates use innate immunityInnate immunity is based on recognition of antigens that are specific to a pathogen

Innate immunity is the first, and most general, mechanism of protection against pathogens.

Which of the following are similarities between B cells and T cells?
I) Both recognize antigens using immunoglobulin receptors.
II) Both undergo clonal selection after encountering an antigen.
III) Both maintain an immunological memory of previously encountered antigens.
II and IIIonly IIonly IIII and II

II and III

Which answer describes an advantage of having a system of adaptive immunity?It enables a rapid defense against an antigen that has been previously encountered.It enables an animal to counter most pathogens almost instantly the first time they are encountered.It results in effector cells with specificity for a large number of antigens.It allows for the production of only a single type of antibody.

It enables a rapid defense against an antigen that has been previously encountered.

Vaccination offers protection against future exposure to pathogens because it ________.stimulates the complement systemtriggers clonal expansion of lymphocytespromotes inflammationenhances the activity of macrophages

triggers clonal expansion of lymphocytes

Which of the following best explains the death of a freshwater fish that had been placed accidentally in saltwater?loss of water by osmosis from cells in vital organs resulted in cell death and organ failurethe gills became encrusted with salt, resulting in inadequate gas exchange and a resulting asphyxiationhigh amounts of salt had diffused into the fish's cells, causing them to swell and lysethe kidneys were not able to keep up with the water removal necessary in this hyperosmotic environment, creating an irrevocable loss of homeostasis

loss of water by osmosis from cells in vital organs resulted in cell death and organ failure

Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to seawater, so they are considered by many to be osmoconformers. Nonetheless, sharks osmoregulate at least partially by ________.monitoring dehydration at the cellular level with special gated aquaporinssynthesizing uric acid, a chemical that binds and precipitates salts inside cellsusing their gills and kidneys to rid themselves of sea saltstolerating high urea concentrations that are balanced with internal salt concentrations to seawater osmolarity

tolerating high urea concentrations that are balanced with internal salt concentrations to seawater osmolarity

In animals, the catabolism of which molecules contributes most to the production of nitrogenous wastes?phospholipids and glycolipidsstarch and celluloseproteins and nucleic acidstriglycerides and steroids

proteins and nucleic acids

Ammonia is likely to be the primary nitrogenous waste from organisms that evolved in which of the following habitats?a freshwater environment that supports fisha marine environment that supports sea birdsa terrestrial environment that supports cricketsa moist system of burrows that supports naked mole rats

a freshwater environment that supports fish

Excretory organs known as Malpighian tubules are present in which of the following organisms?insectsjellyfishsea starsflatworms

insects

conversion of toxic ammonia to less toxic ureamaintenance of homeostasis of pH in body fluidsreabsorption of urea to maintain osmotic balanceregulation of the speed of blood flow through the nephrons

maintenance of homeostasis of pH in body fluids

Use the following figure to answer the question.

Which labeled structure identifies where passive water reabsorption takes place in the kidney?in structures W, X, and Zonly in structure Wonly in structures W and Yin structures V and Z

in structures W, X, and Z

Which of these is absent from insect immunity?antibacterial digestive enzymesproduction of antimicrobial peptidesphagocytosis by hemocytesimmunological memory

immunological memory

B-lymphocytes help develop immunological memory through the production of antibodies that recognize antigens from past infections. B-lymphocytes have the potential to produce millions of different unique antibodies, each potentially binding selectively to unique antigen substrates. This is possible because the genes for B-lymphocyte antigen-binding receptors...contain many unique introns for the variable portions of the light and heavy chains of the molecule that are randomly combined in every possible way prior to antigen recognition. Through these alternative splicing "experiments," the B-lymphocytes create millions of unique antigen-binding receptors. These B-lymphocytes, regardless of whether they recognize a foreign antigen, will always produce millions of unique antibodies.contain millions of unique exons capable of being translated through alternative splicing into millions of unique antigen-binding receptors and thus antibodieshave the highest mutation rate in the genome, orders of magnitude higher than the base mutation rate, thus constantly producing new varieties of protein products despite a limited supply of exons availablecontain many unique exons for the variable portions of the light and heavy chains of the molecule that are randomly combined in every possible way prior to antigen recognition. Through these alternative splicing "experiments," the B-lymphocytes create millions of unique antigen-binding receptors that can be selected upon once one of those varieties successfully binds to an unknown antigen. Once this occurs, that particular B-lymphocyte cell lineage will fix the alternative splicing pattern and remove the other possible exons available, from there on producing only daughter cell lineages capable of making one particular antibody.

contain many unique exons for the variable portions of the light and heavy chains of the molecule that are randomly combined in every possible way prior to antigen recognition. Through these alternative splicing "experiments," the B-lymphocytes create millions of unique antigen-binding receptors that can be selected upon once one of those varieties successfully binds to an unknown antigen. Once this occurs, that particular B-lymphocyte cell lineage will fix the alternative splicing pattern and remove the other possible exons available, from there on producing only daughter cell lineages capable of making one particular antibody.

The body fluids of an osmoconformer would be ________ with its ________ environment.hyperosmotic; freshwaterisoosmotic; seawaterhyperosmotic; seawaterhypoosmotic; seawater

isoosmotic; seawater

Use the following figure to answer the question.

Which labeled structure identifies where filtration take place in the kidney?structure Xstructure Vstructure Wstructure Z

structure V

Salmon eggs hatch in fresh water. The fish then migrate to the ocean (a hyperosmotic solution) and, after several years of feeding and growing, return to fresh water to breed. Which statement best explains how these organisms make the transition from fresh water to ocean water and back to fresh water?Their metabolism changes in salt water to degrade electrolytes.The rectal gland functions in the ocean water, and chloride cells function in fresh water.The salt transport mechanisms of the gill epithelia change during migration.Salmon in fresh water excrete concentrated urine, and salmon in salt water secrete dilute urine.

The salt transport mechanisms of the gill epithelia change during migration.

Which of the following is an advantage of excreting nitrogenous wastes as urea rather than as ammonia?urea can be removed as a semi-solid pasteless nitrogen is removed from the bodyurea does not affect the osmotic gradienturea is less toxic than ammonia

urea is less toxic than ammonia

Which of the following animals generally has the lowest volume of urine production?salmon in fresh watervampire batfreshwater flatwormmarine bony fish

marine bony fish

Part completeA certain cell type has existed in the blood and tissue of its vertebrate host's immune system for over 20 years. One day, it recognizes a newly arrived antigen and binds to it, subsequently initiating a secondary immune response in the body. Which of the following cell types most accurately describes this cell?thyroid cellmacrophageplasma cellmemory cell

memory cell

Many of the current COVID-19 vaccines use an mRNA strand that codes for COVID-19's spike protein, which the COVID-19 virus uses to enter human cells. By what process will an mRNA COVID-19 vaccine lead to immunity to the COVID-19 virus?The mRNA of the COVID-19 vaccine will enter human cells and begin to be translated by the host ribsomes to produce spike proteins identical to those of the COVID-19 virus. These spike proteins will be recognized as foreign by neutrophils and eosinophils once bound to their antigen-binding receptors. Neutrophils will internalize these receptors and begin to manufacture interferons in mass. Once the individual becomes infected with COVID-19, they will now likely have ample immununological memory to fight the infection before the disease state can set in.The mRNA of the COVID-19 vaccine will enter human cells and will be reverse transcribed into the host's genome. From here, the spike protein gene be expressed alongside random genes. These spike protein products will be wielded by macrophages in order to enter the COVID-19 viral particles upon infection, kill the virus from the inside out. The mRNA of the COVID-19 vaccine will enter human cells and begin to be translated by the host ribsomes to produce spike proteins identical to those of the COVID-19 virus. These spike proteins will be recognized as foreign by B and T lymphocytes once bound to their antigen-binding receptors. B cells will internalize these receptors and begin to manufacture antibodies in mass using the same variable regions that recognized the spike protein. Once the individual becomes infected with COVID-19, they will now likely have ample immununological memory to fight the infection before the disease state can set in.The mRNA of the COVID-19 vaccine will enter human cells and begin to be translated by the host ribsomes to produce spike proteins identical to those of the COVID-19 virus. These spike proteins will induce septic shock in the individual, driving the immune system into a ravenous feeding frenzy and thus immunizing the host from any potential infection from all pathogens simlutaneously.

The mRNA of the COVID-19 vaccine will enter human cells and begin to be translated by the host ribsomes to produce spike proteins identical to those of the COVID-19 virus. These spike proteins will be recognized as foreign by B and T lymphocytes once bound to their antigen-binding receptors. B cells will internalize these receptors and begin to manufacture antibodies in mass using the same variable regions that recognized the spike protein. Once the individual becomes infected with COVID-19, they will now likely have ample immununological memory to fight the infection before the disease state can set in.

Lymphocytes mature in the ________.
I) spleen
II) thymus
III) bone marrowonly I and IIIonly I and IIonly II and IIII, II, and III

only II and III

In the human kidney, as filtrate passes down the descending loop of Henle, it becomes _____________. As the filtrate rises up the ascending loop of Henle, it becomes ____________. The final osmolarity of the filtrate will be determined in the ___________.less concentrated; more concentrated; glomerulusmore concentrated; even more concentrated; collecting ductmore concentrated; less concentrated; collecting ductless concentrated; more concentrated; proximal tubule

more concentrated; less concentrated; collecting duct

Which of the following substances does the kidney actively reabsorb from the filtrate?H+K+NaClNH₃+

NaCl

Which of the following is a gas that functions as a local regulator and a neurotransmitter in humans?nitric oxidecarbon dioxideepinephrinecortisol

nitric oxide

Which of the following are the two main systems for communication and control in most animals?digestive system and circulatory systemendocrine system and circulatory systemnervous system and endocrine systemcirculatory system and nervous system

nervous system and endocrine system

Which of the following are properties of steroid hormones?Steroid hormones only act locally, on cells close to where the steroid hormone was secreted.Steroid hormones usually exert their effects on target cells through membrane receptor proteins.Steroid hormones regulate gene transcription by binding to intracellular receptor proteins.Steroid hormones are water-soluble and travel freely in the bloodstream.

Steroid hormones regulate gene transcription by binding to intracellular receptor proteins.

Which of the following is the most likely cause of a goiter?low levels of growth hormonehigh levels of calcium in the dietoverproduction of thyroid hormonelow levels of iodine in the diet

low levels of iodine in the diet

Which two hormones, in a lactating mammal, promote milk synthesis and milk release, respectively?prolactin and calcitoninfollicle-stimulating hormone and luteinizing hormoneluteinizing hormone and oxytocinprolactin and oxytocin

prolactin and oxytocin

Which of the following pairs correctly describes an example of antagonistic hormones that regulate homeostasis?progestins and estrogens control sexual differentiationthyroxine and parathyroid hormones regulate calcium balanceepinephrine and norepinephrine regulate the fight-or-flight responsesinsulin and glucagon regulate blood glucose levels

insulin and glucagon regulate blood glucose levels

Which of the following is a steroid hormone that coordinates molting in arthropods?glucagonecdysteroidgrowth hormonethyroxine

ecdysteroid

Which of the following contributes to poor health when people experience chronic stress?high levels of parathyroid hormones make blood sugar regulation difficulthigh levels of glucocorticoids suppress the immune responsemelatonin levels remain elevatedsuppression of growth hormone allows pathogens to proliferate

high levels of glucocorticoids suppress the immune response

Under which of the following conditions will asexual reproduction be more likely to result in greater reproductive success than sexual reproduction?when there is some potential for rapid overpopulationwhen a species is in a stable and favorable environmentwhen a species is expanding into diverse geographic settingswhen pathogens are rapidly diversifying

when a species is in a stable and favorable environment

A female lizard is kept isolated in a zoo for five years. Then, to everyone's surprise, she lays four viable eggs that hatch to produce offspring that are genetically identical to her. What type of reproduction most likely occurred?parthenogenesissexualbuddingfission

parthenogenesis

Animals that use external fertilization are most likely to reproduce in which of the following areas?polar ice sheettallgrass prairieshallow lakesand dune

shallow lake

Females of many insect species, including honeybee queens, can store sperm in which of the following structures?abdominal tractuterusnestsspermatheca

spermatheca

Where are human sperm produced?prostate glandvas deferensepididymisseminiferous tubules

seminiferous tubules

Among humans, which of the following male and female genital structures consist mostly of erectile tissue?prostate and ovariesvas deferens and oviductpenis and clitoristestes and ovaries

penis and clitoris

Which statement correctly describes the primary function of the corpus luteum?to stimulate the development of the mammary glandsto nourish and protect the egg cellto maintain progesterone and estradiol synthesis after ovulation has occurredto support pregnancy in the second and third trimesters

to maintain progesterone and estradiol synthesis after ovulation has occurred