Deck 32: Homeostasis and Endocrine Signaling

Question 1

Blood is best classified as connective tissue because

A) its cells are separated from each other by an extracellular matrix.
B) it contains more than one type of cell.
C) it is contained in vessels that "connect" different parts of an organism's body.
D) its cells can move from place to place.
E) it is found within all the organs of the body.

Answer 1

A

Question 2

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) all of their bodies have been compressed since birth by intensive underwater pressures.
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) this is the only shape that will allow them to maintain a constant body temperature in water.

Answer 2

D

Question 3

Fibroblasts secrete

A) fats.
B) chondroitin sulfate.
C) interstitial fluids.
D) calcium phosphate for bone.
E) proteins for connective fibers.

Answer 3

E

Question 4

The absorptive epithelia in the gut are considered "polarized" because

A) thick and thin filaments are present.
B) they pump wastes into the lumen while pumping nutrients toward the blood.
C) the colors seen on the top and bottom of the cells are different.
D) they must fire action potentials to absorb most nutrients.
E) the structures on the apical surface are different than those on the basal surface.

Question 5

With its abundance of collagenous fibers, cartilage is an example of

A) connective tissue.
B) reproductive tissue.
C) nervous tissue.
D) epithelial tissue.
E) adipose tissue.

Question 6

Muscles are joined to bones by

A) ligaments.
B) tendons.
C) loose connective tissue.
D) Haversian systems.
E) spindle fibers.

Question 7

All types of muscle tissue have

A) intercalated disks that allow cells to communicate.
B) striated banding patterns seen under the microscope.
C) cells that lengthen when appropriately stimulated.
D) a response that can be consciously controlled.
E) interactions between actin and myosin.

Question 8

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

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

Question 9

An example of a connective tissue is the

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

Question 10

Food moves along the digestive tract as the result of contractions by

A) cardiac muscle.
B) smooth muscle.
C) voluntary muscle.
D) striated muscle.
E) skeletal muscle.

Question 11

Connective tissues typically have

A) many densely packed cells with direct connections between the membranes of adjacent cells.
B) a supporting material such as chondroitin sulfate.
C) the ability to shorten upon stimulation.
D) relatively few cells and a large amount of extracellular matrix.
E) the ability to transmit electrochemical impulses.

Question 12

The type of muscle tissue surrounding internal organs, other than the heart, is

A) skeletal muscle.
B) cardiac muscle.
C) striated muscle.
D) intercalated cells.
E) smooth muscle.

Question 13

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

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

Question 14

The nourishment, insulation, and support for neurons is the result of activity by the

A) smooth muscles.
B) adipose tissue.
C) endocrine system.
D) intercalated disks.
E) glial cells.

Question 15

The body's automatic tendency to maintain a constant and optimal internal environment is termed

A) balanced equilibrium.
B) physiological chance.
C) homeostasis.
D) static equilibrium.
E) estivation.

Question 16

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

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

Question 17

All skeletal muscle fibers are both

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

Question 18

Interstitial fluid is

A) the fluid inside the gastrovascular cavity of Hydra.
B) the internal environment inside animal cells.
C) identical to the composition of blood.
D) the route for the exchange of materials between blood and body cells.
E) found only in the lumen of the small intestine.

Question 19

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

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

Question 20

An example of a properly functioning homeostatic control system is seen when

A) the core body temperature of a runner rises gradually from 37°C to 45°C.
B) the kidneys excrete salt into the urine when dietary salt levels rise.
C) a blood cell shrinks when placed in a solution of salt and water.
D) the blood pressure increases in response to an increase in blood volume.
E) the level of glucose in the blood is abnormally high whether or not a meal has been eaten.

Question 21

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

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

Question 22

Panting by an overheated dog achieves cooling by

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

Question 23

Seasonal changes in snake activity are due to the fact that the snake

A) is less active in winter because the food supply is decreased.
B) is less active in winter because it does not need to avoid predators.
C) is more active in summer because that is the period for mating.
D) is more active in summer because it can gain body heat by conduction.
E) is more active in summer as a result of being disturbed by other animals.

Question 24

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

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

Question 25

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

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

Question 26

Positive feedback differs from negative feedback in that

A) positive feedback benefits the organism, whereas negative feedback is detrimental.
B) the positive feedback's effector responses are in the same direction as the initiating stimulus rather than opposite to it.
C) the effector's response increases some parameter (such as body temperature), whereas in negative feedback it can only decrease the parameter.
D) positive feedback systems have only effectors, whereas negative feedback systems have only receptors.
E) positive feedback systems have control centers that are lacking in negative feedback systems.

Question 27

An example of effectors' roles in homeostatic responses is observable when

A) an increase in body temperature results from involuntary shivering.
B) an increase in body temperature results from exercise.
C) the rising sun causes an increase in body temperature in a stationary animal.
D) an increase in body temperature results from fever.
E) a decrease in body temperature results from shock.

Question 28

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

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

Question 29

The panting responses that are observed in overheated birds and mammals dissipates excess heat by

A) countercurrent exchange.
B) acclimation.
C) vasoconstriction.
D) hibernation.
E) evaporation.

Question 30

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

Question 31

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

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

Question 32

Most land-dwelling invertebrates and all of the amphibians

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

Question 33

All hormones

A) are produced by endocrine glands.
B) are lipid-soluble molecules.
C) are carried to target cells in the blood.
D) are protein molecules.
E) elicit the same biological response from all of their target cells.

Question 34

The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that

A) only its target cells get exposed to aldosterone.
B) only its target cells contain aldosterone receptors.
C) it is unable to enter nontarget cells.
D) nontarget cells destroy aldosterone before it can produce any effect.
E) nontarget cells convert aldosterone to a hormone to which they do respond.

Question 35

Most types of communication between cells utilize

A) the exchange of cytosol between the cells.
B) a direct electrical connection between the cells.
C) the release of chemical signals by the cell sending the message.
D) the exchange of DNA between the cells.
E) the movement of the cells.

Question 36

In a survivably cold environment, an ectotherm is more likely to survive an extended period of food deprivation than would an equally sized endotherm because the ectotherm

A) maintains a higher basal metabolic rate.
B) expends more energy per kg of body mass than does the endotherm.
C) invests little energy in temperature regulation.
D) metabolizes its stored energy more readily than can the endotherm.
E) has greater insulation on its body surface.

Question 37

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

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

Question 38

A cell with membrane-bound proteins that selectively bind a specific hormone is called that hormone's

A) secretory cell.
B) plasma cell.
C) endocrine cell.
D) target cell.
E) regulatory cell.

Question 39

An example of an organism that has only behavioral controls over its body temperature is the

A) green frog.
B) penguin.
C) bluefin tuna.
D) house sparrow.
E) gray wolf.

Question 40

Coordinating body functions via chemical signals is accomplished by

A) the respiratory system.
B) the endocrine system.
C) the immune and lymphatic systems.
D) the integumentary system.
E) the excretory system.

Question 41

For hormones that homeostatically regulate cellular functions,

A) negative feedback typically regulates hormone secretion.
B) the circulating level of a hormone is held constant through a series of positive feedback loops.
C) both lipid-soluble hormones and water-soluble hormones bind to intracellular protein receptors.
D) endocrine organs release their contents into the bloodstream via specialized ducts.
E) it is impossible to also have neural regulation of that system.

Question 42

In a positive-feedback system where hormone A alters the amount of protein X,

A) an increase in A always produces an increase in X, which results in an increase in A.
B) an increase in X always produces a decrease in A, which results in a decrease in X.
C) a decrease in A always produces an increase in X, which results in an increase in A.
D) a decrease in X always causes a decrease in A, which causes an increase in X.
E) it is impossible to predict how A and X affect each other.

Question 43

During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of

A) a negative feedback system.
B) a hormone that acts in an antagonistic way with another hormone.
C) a hormone that is involved in a positive feedback loop.
D) signal transduction immediately changing gene expression in its target cells.
E) the key role of the anterior pituitary gland in regulating uterine contraction.

Question 44

The autonomic nervous system includes an endocrine gland known as the

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

Question 45

Iodine is added to table salt to help prevent deficiencies of an essential mineral needed for the proper function of the

A) parathyroid glands.
B) adrenal glands.
C) thyroid glands.
D) the endocrine pancreas.
E) the exocrine pancreas.

Question 46

The endocrine glands include the

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

Question 47

Hormones that promote homeostasis

A) are not found as members of antagonistic signaling mechanisms.
B) travel to target cells without passage in the plasma.
C) utilize receptors that bind any hormone.
D) initiate signal transduction in the target cell without binding to receptors.
E) usually operate as part of a negative feedback system.

Question 48

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

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

Question 49

Prolactin stimulates mammary gland growth and development in mammals and regulates salt and water balance in freshwater fish. Many scientists think that this wide range of functions indicates that prolactin

A) is a nonspecific hormone.
B) has a unique mechanism for eliciting its effects.
C) is an evolutionarily conserved hormone.
D) is derived from two separate sources.
E) interacts with many different receptor molecules.

Question 50

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

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

Question 51

Portal blood vessels connect two capillary beds found in the

A) hypothalamus and thalamus.
B) anterior pituitary and posterior pituitary.
C) hypothalamus and anterior pituitary.
D) posterior pituitary and thyroid gland.
E) anterior pituitary and adrenal gland.

Question 52

The body's reaction to PTH (parathyroid hormone), a reduction in plasma levels of calcium, can be opposed by

A) thyroxine.
B) epinephrine.
C) growth hormone.
D) calcitonin.
E) glucagon.

Question 53

Melatonin is secreted by

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

Question 54

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

Question 55

Fight-or-flight reactions include activation of

A) the parathyroid glands, leading to increased metabolic rate.
B) the thyroid gland, leading to an increase in the blood calcium concentration.
C) the anterior pituitary gland, leading to cessation of gonadal function.
D) the adrenal medulla, leading to increased secretion of epinephrine.
E) the pancreas, leading to a reduction in the blood sugar concentration.

Question 56

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 neurosecretory cell in the hypothalamus.
D) a brain cell in the cerebral cortex.
E) a cell in the pancreas that produces digestive enzymes.

Question 57

Abnormally reduced somatic growth (dwarfism) can be a consequence of decreased hormone secretion from the

A) kidneys.
B) pancreas.
C) adrenal gland.
D) posterior pituitary gland.
E) anterior pituitary gland.

Question 58

Oxytocin and antidiuretic hormone are synthesized in the

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

Question 59

The hypothalamus

A) functions only as an endocrine target, by having lots of receptors on its cells.
B) functions only in neuronal transmission.
C) does not have any hormone receptors on its cells.
D) secretes tropic hormones that act directly on the gonads.
E) includes neuronal cells that terminate in the posterior pituitary.

Question 60

Most of the exchange surfaces of multicellular animals are lined with

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

Question 61

The nitrogenous waste that requires the most energy to produce is

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

Question 62

Which nitrogenous waste requires hardly any water for its excretion?

A) amino acids
B) urea
C) uric acid
D) ammonia
E) nitrogen gas

Question 63

Ammonia

A) is soluble in water.
B) can be stored in the body as a precipitate.
C) has low toxicity relative to urea.
D) is metabolically more expensive to synthesize than urea.
E) is the major nitrogenous waste excreted by insects.

Question 64

Many marine and freshwater bony fish achieve osmoregulation via

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

Question 65

The fluid with the highest osmolarity is

A) distilled water.
B) plasma in birds.
C) plasma in mammals.
D) seawater in a tidal pool.
E) estuarine water.

Question 66

Which nitrogenous waste has the greatest number of nitrogen atoms?

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

Question 67

In animals, nitrogenous wastes are produced mostly from the catabolism of

A) starch and cellulose.
B) triglycerides and steroids.
C) proteins and nucleic acids.
D) phospholipids and glycolipids.
E) fatty acids and glycerol.

Question 68

Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to seawater, so they are considered by many to be osmoconformers. Nonetheless, these sharks osmoregulate at least partially by

A) using their gills and kidneys to rid themselves of sea salts.
B) monitoring dehydration at the cellular level with special gated aquaporins.
C) tolerating high urea concentrations that balance internal salt concentrations to seawater osmolarity.
D) synthesizing trimethylamine oxide, a chemical that binds and precipitates salts inside cells.
E) possessing a special adaptation that allows their cells to operate at an extraordinarily high salt concentration.

Question 69

The necropsy (postmortem analysis) of a freshwater fish that died after being placed accidentally in saltwater would likely show that

A) loss of water by osmosis from cells in vital organs resulted in cell death and organ failure.
B) high amounts of salt had diffused into the fish's cells, causing them to swell and lyse.
C) the kidneys were not able to keep up with the water removal necessary in this hyperosmotic environment, creating an irrevocable loss of homeostasis.
D) the gills became encrusted with salt, resulting in inadequate gas exchange and a resulting asphyxiation.
E) brain cells lysed as a result of increased osmotic pressure in this hyperosmotic environment, leading to death by loss of autonomic function.

Question 70

Organisms categorized as osmoconformers are most likely

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

Question 71

Urea is produced in the

A) liver from NH3 and CO2.
B) liver from glycogen.
C) kidneys from glucose.
D) kidneys from glycerol and fatty acids.
E) bladder from uric acid and H2O.

Question 72

Ammonia is likely to be the primary nitrogenous waste in living conditions that include

A) lots of fresh water flowing across the gills of a fish.
B) lots of seawater, such as a bird living in a marine environment.
C) lots of seawater, such as the environment of a marine mammal (e.g., a polar bear).
D) a terrestrial environment, such as that supporting crickets.
E) a moist system of burrows, such as those of naked mole rats.

Question 73

The advantage of excreting nitrogenous wastes as urea rather than as ammonia is that

A) urea can be exchanged for Na+.
B) urea is less toxic than ammonia.
C) urea requires more water for excretion than ammonia.
D) urea does not affect the osmolar gradient.
E) less nitrogen is removed from the body.

Question 74

Compared to the seawater around them, most marine invertebrates are

A) hyperosmotic.
B) hypoosmotic.
C) isoosmotic.
D) hyperosmotic and isoosmotic.
E) hypoosmotic and isoosmotic.

Question 75

The primary nitrogenous waste excreted by birds is

A) ammonia.
B) nitrate.
C) nitrite.
D) urea.
E) uric acid.

Question 76

Birds secrete uric acid as their nitrogenous waste because uric acid

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

Question 77

A human who has no access to fresh water but is forced to drink seawater instead

A) will thrive under such conditions, as long as he has lived at the ocean most of his life.
B) will excrete more water molecules than taken in, because of the high load of ion ingestion.
C) will develop structural changes in the kidneys to accommodate the salt overload.
D) will find that drinking saltwater satiates his thirst.
E) will risk becoming overhydrated within 12 hours.

Question 78

Urea is

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

Question 79

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

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

Question 80

Among vertebrate animals, urea

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