Choose a pair that correctly associates the mechanism for osmoregulation or nitrogen removal with the appropriate animal.

Choose a pair that correctly associates the mechanism for osmoregulation or nitrogen removal with the appropriate animal.

A) exchange across the body surfaceNmarine invertebrate
B) Malpighian tubuleNfrog
C) flame bulbNsnake
D) kidneyNinsect
E) metanephridium flatworm



Answer: A

Among vertebrate animals, urea

Among vertebrate animals, urea 

A) is made in the pancreas and added to the intestinal contents, along with bile salts, for excretion.
B) is rarely the nitrogenous waste of choice.
C) is added to the air in the lungs to be exhaled, along with carbon dioxide.
D) is made in the liver by combining two ammonia molecules with one carbon dioxide.
E) is made in the kidneys and immediately excreted.



Answer: D

Excretory organs known as Malpighian tubules are present in

Excretory organs known as Malpighian tubules are present in 

A) flatworms.
B) insects.
C) jellyfish.
D) sea stars.
E) earthworms.


Answer: B

If you gently twist your earlobe, it does not remain distorted because it contains

If you gently twist your earlobe, it does not remain distorted because it contains 

A) collagenous fibers.
B) elastic fibers.
C) reticular fibers.
D) loose connective tissue.
E) adipose tissue.



Answer: B

After drinking alcoholic beverages, increased urine excretion is the result of

After drinking alcoholic beverages, increased urine excretion is the result of 

A) the osmoregulator cells of the brain increasing their activity.
B) increased aldosterone production.
C) inhibited secretion of antidiuretic hormone (ADH).
D) increased reabsorption of water in the proximal tubule.
E) increased blood pressure.



Answer: C

The temperature-regulating center of vertebrate animals is located in the

The temperature-regulating center of vertebrate animals is located in the 

A) medulla oblongata.
B) hypothalamus.
C) thyroid gland.
D) liver.
E) subcutaneous layer of the skin.



Answer: B

Different body cells can respond differently to the same peptide hormones because

Different body cells can respond differently to the same peptide hormones because 

A) each cell converts that hormone to a different metabolite.
B) a target cell's response is determined by the components of its signal transduction pathways.
C) the circulatory system regulates responses to hormones by routing the hormones to specific targets.
D) different target cells have different sets of genes.
E) the hormone is chemically altered in different ways as it travels through the circulatory system.



Answer: B

All skeletal muscle fibers are both

All skeletal muscle fibers are both 

A) striated and electrically coupled to neighboring fibers.
B) smooth and operate independently of other skeletal muscle fibers.
C) smooth and under voluntary control.
D) smooth and under involuntary control.
E) striated and under voluntary control.


Answer: E

Which of the following is an accurate statement about thermoregulation?

Which of the following is an accurate statement about thermoregulation? 

A) Endotherms are warm-blooded and ectotherms are cold-blooded.
B) Endotherms maintain a constant body temperature and ectotherms do not.
C) Endothermy has a lower energy cost than ectothermy.
D) Endotherms and ectotherms differ in their primary source of heat for thermoregulation.
E) Endotherms are regulators and ectotherms are conformers.



Answer: D

A necropsy (postmortem analysis) of a marine sea star that died after it was mistakenly placed in fresh water would likely show that it died because

A necropsy (postmortem analysis) of a marine sea star that died after it was mistakenly placed in fresh water would likely show that it died because

A) its contractile vacuoles ruptured.
B) the sea star's kidneys could not handle the change in ionic content presented by the fresh water.
C) it was so hyperosmotic to the fresh water that it could not osmoregulate.
D) its cells dehydrated and lost the ability to metabolize.
E) it was stressed and needed more time to acclimate to the new conditions.



Answer: C

Organisms categorized as osmoconformers are most likely

Organisms categorized as osmoconformers are most likely 

A) found in terrestrial environments with adequate moisture.
B) found in freshwater lakes and streams.
C) marine.
D) amphibious.
E) found in arid terrestrial environments.



Answer: C

After blood flow is artificially reduced at one kidney, you would expect that kidney to secrete more of the hormone known as

After blood flow is artificially reduced at one kidney, you would expect that kidney to secrete more of the hormone known as

A) erythropoietin.
B) antidiuretic hormone.
C) angiotensinogen.
D) atrial natriuretic peptide.
E) renin.



Answer: E

When a steroid hormone and a peptide hormone exert similar effects on a population of target cells, then

When a steroid hormone and a peptide hormone exert similar effects on a population of target cells, then

A) the steroid hormones affect only the release of proteins from the target cell, whereas peptide hormones affect only the synthesis of proteins that remain in the target cell.
B) the steroid hormones affect the synthesis of effector proteins, whereas peptide hormones activate effector proteins already present in the cell.
C) the steroid hormones affect the activity of certain proteins within the cell, whereas peptide hormones directly affect the processing of mRNA.
D) the steroid and peptide hormones must bind to the same receptor protein.
E) the steroid and peptide hormones must use the same biochemical mechanisms.



Answer: B

In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, are

In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, are

A) prolactin and luteinizing hormone.
B) prolactin and calcitonin.
C) follicle-stimulating hormone and luteinizing hormone.
D) luteinizing hormone and oxytocin.
E) prolactin and oxytocin.


Answer: E

The autonomic nervous system includes an endocrine gland known as the

The autonomic nervous system includes an endocrine gland known as the 

A) adrenal medulla.
B) adrenal cortex.
C) thyroid.
D) testis.
E) ovary.



Answer: A

An exchange surface in direct contact with the external environment is found in the

An exchange surface in direct contact with the external environment is found in the 

A) liver.
B) brain.
C) heart.
D) skeletal muscles.
E) lungs.



Answer: E

Within a normally functioning kidney, blood can be found in

Within a normally functioning kidney, blood can be found in 

A) Bowman's capsule.
B) the loop of Henle.
C) the proximal tubule.
D) the vasa recta.
E) the collecting duct.



Answer: D

Panting by an overheated dog achieves cooling by

Panting by an overheated dog achieves cooling by 

A) torpor.
B) evaporation.
C) shivering thermogenesis.
D) acclimatization.
E) nonshivering thermogenesis.


Answer: B

Humans can lose, but cannot gain, heat through the process of

Humans can lose, but cannot gain, heat through the process of 

A) radiation.
B) conduction.
C) metabolism.
D) convection.
E) evaporation.



Answer: E

Most land-dwelling invertebrates and all of the amphibians

Most land-dwelling invertebrates and all of the amphibians 

A) alter their metabolic rates to maintain a constant body temperature of 37°C.
B) are ectothermic organisms with variable body temperatures.
C) have a net loss of heat across a moist body surface, even in direct sun.
D) become more active when environmental temperatures drop below 15°C.
E) are endotherms but become thermoconformers only when they are in water.



Answer: B

Urea is

Urea is 

A) more toxic to human cells than ammonia.
B) insoluble in water.
C) the primary nitrogenous waste product of humans.
D) the primary nitrogenous waste product of most aquatic invertebrates.
E) the primary nitrogenous waste product of most birds.



Answer: C

Which of the following would increase the rate of heat exchange between an animal and its environment?

Which of the following would increase the rate of heat exchange between an animal and its environment?

A) blubber or fat layer
B) vasoconstriction
C) feathers or fur
D) wind blowing across the body surface
E) countercurrent heat exchanger



Answer: D

Many marine and freshwater bony fish achieve osmoregulation via

Many marine and freshwater bony fish achieve osmoregulation via 

A) loss of water in the urine.
B) no drinking of water.
C) gain of salt through the gills.
D) gain of water through food.
E) loss of water through the gills.



Answer: D

The interrelationships between the endocrine and the nervous systems are especially apparent in

The interrelationships between the endocrine and the nervous systems are especially apparent in 

A) a neuron in the spinal cord.
B) a steroid-producing cell in the adrenal cortex.
C) a cell in the pancreas that produces digestive enzymes.
D) a brain cell in the cerebral cortex.
E) a neurosecretory cell in the hypothalamus.



Answer: E

Materials are returned to the blood from the filtrate by which of the following processes?

Materials are returned to the blood from the filtrate by which of the following processes? 

A) ultrafiltration
B) excretion
C) selective reabsorption
D) filtration
E) secretion



Answer: C

Which of the following pairs of organisms excrete nitrogenous wastes in the form of uric acid?

Which of the following pairs of organisms excrete nitrogenous wastes in the form of uric acid? 

A) insects and birds
B) lions and horses
C) mice and birds
D) fish and turtles
E) humans and frogs



Answer: A

The osmoregulatory/excretory system of an insect is based on the operation of

The osmoregulatory/excretory system of an insect is based on the operation of 

A) metanephridia.
B) ananephredia.
C) Malpighian tubules.
D) nephrons.
E) protonephridia.



Answer: C

An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the

An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the

A) protonephridia of rotifers.
B) flame bulb system of flatworms.
C) Malpighian tubules of insects.
D) kidneys of vertebrates.
E) metanephridia of earthworms.



Answer: D

Birds secrete uric acid as their nitrogenous waste because uric acid

Birds secrete uric acid as their nitrogenous waste because uric acid 

A) requires little water for nitrogenous waste disposal, thus reducing body mass.
B) is metabolically less expensive to synthesize than other excretory products.
C) excretion allows birds to live in desert environments.
D) is readily soluble in water.


Answer: A

Most of the exchange surfaces of multicellular animals are lined with

Most of the exchange surfaces of multicellular animals are lined with

A) adipose tissue.
B) connective tissue.
C) smooth muscle cells.
D) epithelial tissue.
E) neural tissue.


Answer: D

The transfer of fluid from the glomerulus to Bowman's capsule

The transfer of fluid from the glomerulus to Bowman's capsule 

A) transfers large molecules as easily as small ones.
B) usually includes the transfer of red blood cells into Bowman's capsule.
C) is mainly a consequence of blood pressure in the capillaries of the glomerulus.
D) results from active transport.
E) is very selective as to which sub protein-sized molecules are transferred.


Answer: C

Tissues are composed of cells, and tissues functioning together make up

Tissues are composed of cells, and tissues functioning together make up 

A) organelles.
B) organ systems.
C) membranes.
D) organs.
E) organisms.



Answer: D

An example of a connective tissue is the

An example of a connective tissue is the 

A) cuboidal epithelium.
B) skin.
C) blood.
D) smooth muscles.
E) nerves.


Answer: C

The filtrate in the proximal convoluted tubule of the human does not normally include

The filtrate in the proximal convoluted tubule of the human does not normally include 

A) plasma proteins.
B) amino acids.
C) glucose.
D) dissolved gasses.
E) ions.



Answer: A

ADH and RAAS work together in maintaining osmoregulatory homeostasis through which of the following ways?

ADH and RAAS work together in maintaining osmoregulatory homeostasis through which of the following ways?

A) ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and RAAS maintains the osmolarity of the blood by stimulating Na+ and water reabsorption.
B) both stimulate the adrenal gland to secrete aldosterone, which increases both blood volume and pressure via receptors in the urinary bladder.
C) ADH and RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and RAAS causes increased excretion of water when it is in excess in body fluids.
D) ADH regulates the osmolarity of the blood and RAAS regulates the volume of the blood.
E) by combining at the receptor sites of proximal tubule cells, where reabsorption of essential nutrients takes place.



Answer: A

Oxytocin and antidiuretic hormone are synthesized in the

Oxytocin and antidiuretic hormone are synthesized in the 

A) adrenal cortex.
B) adenohypophysis.
C) hypothalamus.
D) posterior pituitary.
E) anterior pituitary.


Answer: C

Melatonin is secreted by

Melatonin is secreted by 

A) the autonomic nervous system during the winter.
B) the thyroid gland during cold seasons.
C) the posterior pituitary gland during the day.
D) the pineal gland during the night.
E) the hypothalamus during the day.


Answer: C

An example of an ectothermic organism that has few or no behavioral options when it comes to its ability to adjust its body temperature is a

An example of an ectothermic organism that has few or no behavioral options when it comes to its ability to adjust its body temperature is a

A) terrestrial lizard.
B) honeybee in a hive.
C) sea star, a marine invertebrate.
D) bluefin tuna, a predatory fish.
E) hummingbird.



Answer: C

Penguins, seals, and tuna have body forms that permit rapid swimming, because

Penguins, seals, and tuna have body forms that permit rapid swimming, because 

A) all share a common ancestor at some point in the past.
B) this is the only shape that will allow them to maintain a constant body temperature in water.
C) flying, pregnancy, and gill-breathing all require similar adaptations in form.
D) the shape is a convergent evolutionary solution to the need to reduce drag while swimming.
E) all of their bodies have been compressed since birth by intensive underwater pressures.



Answer: D

The thermoregulatory response of an overheated dog in a very hot environment is impaired if the response causes

The thermoregulatory response of an overheated dog in a very hot environment is impaired if the response causes

A) body temperature to increase to match the environmental temperature.
B) evaporative heat loss to increase.
C) a behavioral response that takes the dog to a cooler location.
D) blood vessels near the skin to vasoconstrict.
E) metabolic heat production to decrease.



Answer: A

Homeostasis typically relies on negative feedback because positive feedback

Homeostasis typically relies on negative feedback because positive feedback 

A) requires a response but not a stimulus.
B) drives processes to completion rather than to a balance point.
C) involves one location rather than several across the body.
D) acts within, but not beyond, a normal range.
E) can decrease but not increase a variable.



Answer: B

The body fluids of an osmoconformer would be ________ with its ________ environment.

The body fluids of an osmoconformer would be ________ with its ________ environment. 

A) isotonic; freshwater
B) hypoosmotic; saltwater
C) hyperosmotic; saltwater
D) isoosmotic; saltwater
E) hyperosmotic; freshwater



Answer: D

The typical osmolarity of human blood is

The typical osmolarity of human blood is 

A) 500 mosm/L.
B) 100 mosm/L.
C) 30 mosm/L.
D) 300 mosm/L.
E) 200 mosm/L.


Answer: D

The increased contraction of the human uterus during labor and delivery is at least partially due to the actions of

The increased contraction of the human uterus during labor and delivery is at least partially due to the actions of

A) oxytocin.
B) ecdysteroid.
C) glucagon.
D) thyroxine.
E) growth hormone.



Answer: A

Osmoregulatory adjustment via the renin-angiotensin-aldosterone system can be triggered by

Osmoregulatory adjustment via the renin-angiotensin-aldosterone system can be triggered by 

A) drinking several glasses of water.
B) eating a pizza with olives and pepperoni.
C) severe sweating on a hot day.
D) eating a bag of potato chips.
E) sleeping for one hour.


Answer: C

Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species?

Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species?

A) a mouse species living in a desert
B) a mouse species living in a temperate broadleaf forest
C) a river otter
D) a beaver
E) a mouse species living in a tropical rain forest


Answer: A

Which nitrogenous waste has the greatest number of nitrogen atoms?

Which nitrogenous waste has the greatest number of nitrogen atoms? 

A) uric acid
B) ammonia
C) urea
D) ammonium ions



Answer: A

Which of the following has (have) both endocrine and exocrine activity?

Which of the following has (have) both endocrine and exocrine activity? 

A) adrenal glands
B) the pituitary gland
C) the pancreas
D) parathyroid glands
E) salivary glands


Answer: C

In a typical nerve cell, the nucleus is found in the

In a typical nerve cell, the nucleus is found in the 

A) dendritic region.
B) synaptic terminals.
C) cell body.
D) axonal region.
E) synapse.


Answer: C

The endocrine glands include the

The endocrine glands include the 

A) sebaceous glands.
B) parathyroid glands.
C) salivary glands.
D) sweat glands.
E) gallbladder.


Answer: B

When stimulated by aldosterone, the reabsorption of Na+ is increased along

When stimulated by aldosterone, the reabsorption of Na+ is increased along 

A) Bowman's capsule.
B) the loop of Henle.
C) the glomerulus.
D) the distal tubule.
E) the proximal tubule.

Answer: D