Deck 20: Maintaining the Internal Environment

Question 1

In order to help circulate heat gained from the environment while basking, marine iguanas

A) reduce their heart rates.
B) increase the flow of blood to their skin.
C) reduce the flow of blood to their skin.
D) dive into cold waters.

Answer 1

B

Question 2

In order to maintain constant internal conditions, an animal

A) must produce more metabolic heat than it loses to its surroundings.
B) needs to take in more water than it loses to its surroundings.
C) needs to lose and gain equal amounts of heat and water but lose more solutes than it gains.
D) must gain and lose equal amounts of heat, solutes, and water.

Answer 2

D

Question 3

Individual cells that are deeply embedded in a large animal are surrounded by _________, which provides nutrients, delivers hormones, and carryies away wastes.

A) a plasma membrane
B) interstitial fluid
C) blood plasma
D) capillaries

Answer 3

B

Question 4

Which of the following statements about temperature regulation is false?

A) All organisms maintain the same core temperature.
B) Some organisms maintain a constant core temperature even when the external environment changes.
C) Some organisms' core temperatures vary when the external environment varies.
D) Different organisms may have different core temperatures at which they do well.

Question 5

The physical movement of heat that results from the movement of air or water is known as

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

Question 6

A breeze cools a hot, dry surface by

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

Question 7

After about an hour of basking in the sun, the body temperature of the marine iguana reaches 37°C and they dive into the water to feed. In the water, their body temperature rapidly drops and they must return to the rocks to warm up. This is an example of

A) endothermic behavior.
B) positive feedback.
C) ectothermic conduction.
D) negative feedback.

Question 8

A person whose hands are being warmed by holding a hot cup of tea is gaining heat by

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

Question 9

An organism that generates enough metabolic heat to contribute in an important way to its heat gain is known as a(n)

A) ectotherm.
B) endotherm.
C) mesotherm.
D) basker.

Question 10

Negative feedback

A) stops a process, before it reaches its set point.
B) determines what the set point of a process should be.
C) slows down or shuts off a process when a set point is reached.
D) prevents positive feedback.

Question 11

When a dog pants (breathes in and out rapidly through the mouth), evaporative cooling is enhanced by

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

Question 12

Why do animals that live in cold climates have thick fur coats?

A) Fur reduces convection and traps a layer of air heated by conduction close to the skin, keeping the animal's body warmer.
B) Thicker fur allows animals to better blend into the environment, providing protection from other animals.
C) Fur decreases the surface area-to-volume ratio of the animal so it does not lose as much heat.
D) Fur prevents the formation of ice crystals next to the skin of the animal, which prevents cells from freezing and being damaged by ice.

Question 13

Some species of fish that live in the cold waters of the Arctic Ocean have evolved an "antifreeze" protein. Why might this protein be important to homeostasis?

A) The protein might be involved in transporting water into fish cells during cold weather. The more water in the cell, the smaller the chance that ice crystals will form.
B) The protein might prevent ice crystals from forming inside cells, which would prevent damage to the plasma membrane when temperatures are low.
C) The protein might be involved in removing solutes from fish cells during cold weather. With fewer solutes in the cell, essential chemical reactions are more likely to occur.
D) The protein might allow this species of fish to survive global warming by allowing it to carry out chemical reactions that would normally be prevented by warm temperatures.

Question 14

Which of the following is not a means used by chickadees to conserve heat in the winter?

A) reducing convection
B) reducing radiation
C) reducing metabolism
D) reducing evaporation

Question 15

Metabolic heat is generated by

A) biochemical reactions.
B) contracting muscles.
C) taking this test.
D) all of the above

Question 16

Cooling by evaporation requires

A) radiation.
B) a dried surface.
C) a wet surface.
D) conduction.

Question 17

Which of the following statements about homeostasis is false?

A) The more solutes present in a cell, the better it functions. Homeostasis is used to make sure that all available solutes are pumped into cells.
B) The enzymes that run an organism have evolved to function best under certain conditions. Maintaining homeostasis allows enzymes to function optimally.
C) High temperatures can cause proteins to unfold. Maintaining a set temperature in an organism through homeostasis prevents this from happening.
D) Water dilutes solutes, making it difficult for reactants to get together and perform chemical reactions. Homeostasis ensures that the proper amount of water is retained within cells.

Question 18

The iguana shown in the image below has just climbed out of the ocean and has a body temperature that is lower than the air temperature.
What do the arrows illustrating heat transfer from the iguana indicate?

A) The iguana is gaining heat as a result of evaporation of salt from its body.
B) The iguana is gaining heat from conduction from the sun.
C) The iguana is losing heat as a result of radiation of metabolic heat.
D) The iguana is losing heat as a result of evaporation of water off its skin.

Question 19

Animal A has a surface area of 6 cm² and a volume of 1 cm³. Animal B has a surface area of 24 cm² and a volume of 8 cm³. If each animal were in the same environment,

A) animals A and B would gain and lose solutes at the same rate, but animal A would gain heat faster.
B) animal B would gain water faster than animal A, but animal A would lose solutes faster.
C) animal A would gain or lose heat, water, and solutes faster than animal B.
D) animal B would lose heat faster than animal A but gain water faster.

Question 20

The circulation of blood through the body increases the rate of heat transfers by

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

Question 21

Examine the table below.
Based on the data in this table, which organism is most likely to be an osmoconformer? Note that lobsters and flounders live in salt water and goldfish live in freshwater.

A) lobster
B) flounder
C) goldfish
D) humans

Question 22

As the filtrate moves through a nephron

A) water is added to make a dilute urine.
B) solutes are combined with urea.
C) water and solutes are reabsorbed.
D) we get thirsty due to the salts that are taken back into the blood.

Question 23

A soluble waste product builds up in a cell. Which of the following takes place?

A) The waste product first diffuses into a capillary.
B) The waste product first diffuses into the interstitial fluid.
C) The waste product first diffuses into blood plasma.
D) The waste product diffuses into the cell's plasma membrane and remains there, until the cell dies.

Question 24

One reason we get thirsty is that

A) our kidneys cannot reabsorb about a bathtub's volume of water each day.
B) blood flowing through the glomerulus loses all of its salts.
C) blood in capillaries moves directly into tubules.
D) some water is lost in the production of a dilute urine.

Question 25

Which of the following would be the best way to avoid heatstroke on a very hot day?

A) Apply chemicals to your skin that prevent you from sweating.
B) Wear dark-colored clothing to shield yourself from the sun.
C) Spray your body with water from a hose and then allow the water to evaporate.
D) Consume beverages that are very high in solutes.

Question 26

As a cell takes up glucose from surrounding interstitial fluid,

A) glucose will begin to diffuse back out of the cell because the concentration will eventually exceed that of the interstitial fluid.
B) solutes in the blood plasma will also begin to take up glucose from the interstitial fluid.
C) glucose will diffuse from blood plasma into the interstitial fluid.
D) glucose will begin to diffuse into and out of the interstitial fluid across capillary walls at the same rate.

Question 27

In our kidneys, blood gets filtered in

A) the glomerulus.
B) the tubules.
C) capillaries surrounding the tubules.
D) the bladder.

Question 28

If you have ever breathed air out of your lungs onto a cold glass surface, you have seen the glass "fog up" from water contained in your breath. Which of the descriptions below describes the journey of that water from a cell in your body to your breath?

A) blood plasma to lungs to capillary to interstitial fluid across the plasma membrane to cell interior
B) cell interior across the plasma membrane to blood plasma to interstitial fluid to capillary to lungs
C) cell interior across the plasma membrane to capillary to interstitial fluid to blood plasma to lungs
D) cell interior across the plasma membrane to interstitial fluid to capillary to blood plasma to lungs

Question 29

An iguana swimming in water colder than its body temperature

A) balances the loss through metabolism.
B) gains heat from the water by reverse conduction.
C) loses heat by conduction and convection.
D) retains heat by increasing its heart rate.

Question 30

To maintain homeostasis of its body fluids, a frog in freshwater would have to

A) actively transport salts out and excrete dilute urine.
B) actively transport salts in and excrete concentrated urine.
C) actively transport water out and excrete dilute urine.
D) actively transport salts in and excrete dilute urine.

Question 31

The distances between capillaries and cell surfaces near capillaries are

A) too great for only diffusion to transport materials quickly enough.
B) so small that materials can diffuse quickly enough to move materials as needed.
C) so small that materials sometimes diffuse in the wrong direction.
D) just large enough to make transport of materials happen only one way at a time.

Question 32

The figure below illustrates how the nephron in a human kidney aids in the removal of toxic by-products of protein metabolism and assists in the regulation of internal water and solute concentrations.
In the region of the nephron labeled "tubule," sodium is

A) leaving the tubule by diffusion.
B) being actively pumped out of the tubule.
C) moving out of the tubule through osmosis.
D) exiting the tubule via secretion.

Question 33

A molecule of ammonia leaving a cell would first move into

A) a capillary.
B) the interstitial fluid.
C) the blood plasma.
D) a nephron.

Question 34

Marine fish must use energy to maintain their body fluid balance, because

A) they live in a hypertonic environment and need to use energy to retain water.
B) they must get rid of the excess water that constantly moves into their interstitial fluid.
C) they must actively take up solutes from their surroundings.
D) their kidneys must reabsorb solutes from the external surroundings.

Question 35

Heatstroke results primarily from

A) a loss of conductive cooling.
B) a loss of evaporative cooling.
C) a loss of radiative cooling.
D) a loss of convective cooling.

Question 36

Which of the following compounds allows the animal that makes it to remove a toxic waste product with the least associated amount of water loss?

A) ammonia in freshwater fish
B) ammonia in saltwater fish
C) urea in humans
D) uric acid in birds

Question 37

Which of the following is not reabsorbed as the filtrate from the glomerulus moves through the nephron?

A) urea
B) glucose
C) water
D) creatinine

Question 38

Ammonia is produced by the metabolism of

A) fatty acids.
B) glucose.
C) proteins.
D) carbohydrates.

Question 39

Which of the following is not a function of kidneys?

A) filtration
B) urination
C) reabsorption
D) secretion

Question 40

Capillary walls

A) act as barriers to excessive movement of materials to and from blood plasma.
B) are selectively permeable, allowing only one-way movement of materials from interstitial fluid to blood plasma.
C) are thin walled, allowing diffusion of materials to and from blood plasma and interstitial fluid.
D) actively transport materials from blood plasma to interstitial fluid.

Question 41

The process of regulating internal conditions so that they remain steady even when the physical environment does not match them is called ___________.

Question 42

Animals can gain, but not lose, heat by conduction.

Question 43

Secretion and ____________ take place in the U-shaped kidney tubule.

Question 44

An animal that does not maintain a relatively constant core temperature is a(n) _________.

Question 45

A large glass of ice water and a small glass of ice water are sitting on a table in the same room. The small glass of water would reach room temperature before the large glass of water.

Question 46

How might air conditioning reduce the number of deaths resulting from heat waves?

A) When a person is standing in front of the air conditioner, the air blowing out replaces the warmer air next to the person's body, allowing conduction, radiation, and evaporation to be more efficient at removing heat from the body.
B) In a cooler room, the temperature difference between a person's body and the air is larger than it is when a person is sitting outside on a hot day. As a result, heat is lost faster in an air-conditioned room.
C) As air conditioning acts to lower the body temperature, less water is lost from a person's body through evaporation, preventing dehydration.
D) all of the above

Question 47

Most marine animals and all land animals are ____________ because they maintain internal salt and water levels that are not the same as those of their surroundings.

Question 48

________ feedback keeps the internal environment in a constant state within a range of external conditions.

Question 49

An animal can lose heat by ___________ even when the environmental temperature is greater than its internal temperature.

Question 50

__________ tissue, the interface between an organism and its environment, regulates the amount of water, heat, and other substances that are exchanged with the external environment.

Question 51

Evaporation cools by radiation.

Question 52

Shivering and goose bumps are ways of producing _____.

Question 53

During the day, camels allow their body temperature to rise to up to 40.5°C. At night, their temperature drops back to normal as a result of __________ when the air temperature drops below the camel's body temperature.

Question 54

Animals can gain or lose heat by conduction and radiation, but the process of ___________ only results in heat loss.

Question 55

A turtle lying on a warm rock on a sunny day is gaining heat from the sun by radiation and heat from the rock by _____________.

Question 56

In kidneys, the glomerulus is composed of a bed of __________.

Question 57

Ectotherms depend more on heat from their environment than on _________ heat from internal chemical reactions.

Question 58

Sweating results in heat loss by convection.

Question 59

Frostbitten tissue, because water within cells freezes, expands, and ruptures plasma membranes.

Question 60

The basic functioning unit of the kidney is the _______.

Question 61

In a nephron the filtrate is derived from blood plasma.

Question 62

Conduction is a form of convection.

Question 63

Why must freshwater fish use energy to maintain a balance of body fluids?

Question 64

Heat can be gained or lost by radiation.

Question 65

Kidneys conserve water but not solutes.

Question 66

Urea is reabsorbed by the kidney because it acts as an antioxidant, protecting cells from damaging chemicals produced by metabolic reactions.