Deck 27: Water and Salt Physiology: Introduction and Mechanisms

Question 1

Larger crustaceans, such as a blue crab, have an exoskeleton impregnated with

A) cellulose.
B) calcium.
C) phospholipids.
D) proteoglycans.

Answer 1

B

Question 2

Humans turnover about _______ of their water daily and in smaller mammals like mice, this turnover is about _______.

A) 25%; 7%
B) 60%; 25%
C) 7%; 25%
D) 25%; 60%

Answer 2

C

Question 3

The purpose of taking excess water into the body during the process of molting is to

A) provide structural rigidity.
B) increase the osmotic pressure.
C) expand the body to make a larger exoskeleton.
D) provide structural rigidity and expand the body to make a larger exoskeleton.

Answer 3

D

Question 4

Most mammals are _______ water.

A) 40%
B) 50%
C) 60%
D) 80%

Question 5

In the body, water is found in the largest quantity in the

A) extracellular fluid.
B) interstitial fluid.
C) intracellular fluid.
D) plasma.

Question 6

In a person who weighs 70 kg, _______ of that is water.

A) 30 kg
B) 42 kg
C) 52 kg
D) 62 kg

Question 7

Which statement about the importance of ions in body fluids is false?

A) Ionic concentrations can have a direct effect on the three-dimensional shape of proteins and thus their function.
B) Ionic concentrations can change the pH, increasing it or decreasing, thus affecting the function of proteins.
C) Ionic concentrations can affect synaptic transmission in neurons.
D) Ionic concentrations have no effect on the rhythm of the heart.

Question 8

Which process directly uses ATP to move ions to cross the cell membrane?

A) Simple diffusion
B) Facilitated diffusion
C) Primary active transport
D) Secondary active transport

Question 9

Which of the following does not allow movement of water across a cell membrane?

A) Carriers
B) Endocytotic vesicles
C) Channels
D) The lipid portion of the membrane

Question 10

_______ allow for water and ion movement across the blood-capillary endothelium.

A) Pores
B) Channels
C) Carriers
D) Transporters

Question 11

Typically, if the blood osmolarity were 500 mOsm, then interstitial fluid osmolarity would be _______ mOsm.

A) 300
B) 400
C) 500
D) 600

Question 12

If you submerge a mussel in an environment in which the ambient osmotic pressure progressively increases, the blood osmotic pressure of the mussel will

A) progressively increase.
B) progressively decrease.
C) increase first and then decrease.
D) not change.

Question 13

If you submerge an animal in an environment in which the ambient osmotic pressure increases, but the animal's blood osmotic pressure does not change, it can be concluded that this animal is a

A) conformer.
B) regulator.
C) migrator.
D) concentrator.

Question 14

The maintenance of a constant concentration of ions in the blood plasma is known as

A) ionic conformity.
B) ionic regulation.
C) volume regulation.
D) volume conformity.

Question 15

If you go to the movie theater and eat a large bag of salted popcorn, after few hours your plasma salt concentration will

A) increase.
B) decrease.
C) be at the normal level.
D) increase and then decrease.

Question 16

If you go to the movie theater and eat a large bag of popcorn with salt, after few minutes, your plasma salt concentration will

A) increase.
B) decrease.
C) be at the normal level.
D) increase and then decrease.

Question 17

If a freshwater fish takes in a quantity of water from its dilute environment by osmosis, the osmotic pressure in its plasma will tend to

A) increase.
B) decrease.
C) remain the same.
D) increase then decrease.

Question 18

Refer to the figure shown.
What does the dotted line represent?

A) The isosmotic line
B) The line of regulation
C) Ambient osmotic pressure
D) The ideal osmotic pressure

Question 19

Refer to the figure shown.
Which animal is a regulator?

A) Green crab
B) Mussel
C) Shrimp
D) Green crab and shrimp

Question 20

Refer to the figure shown.
Based on the data shown, which animal can survive the widest range of salinity?

A) Green crab
B) Mussel
C) Shrimp
D) Green crab and shrimp

Question 21

Refer to the figure shown.
Which animal is a conformer?

A) Green crab
B) Mussel
C) Shrimp
D) Green crab and mussel

Question 22

Seawater in the open ocean has a uniform salinity of _______ g/kg.

A) 32-48
B) 30-32
C) 32-34
D) 34-46

Question 23

The mix of freshwater with ocean water along coastlines is termed

A) freshwater mixing.
B) saltwater mixing.
C) brackish water.
D) pond water.

Question 24

Choose a salinity that isn't commonly measured in an estuary like Chesapeake Bay.

A) 3 g/kg
B) 5 g/kg
C) 15 g/kg
D) 35 g/kg

Question 25

Humidity refers to the _______ content in the atmosphere.

A) oxygen
B) water
C) carbon dioxide
D) nitrogen

Question 26

Evaporation occurs if the partial pressure in a solution

A) is below the partial pressure in the plasma.
B) is below the partial pressure in the atmosphere.
C) exceeds the partial pressure in the plasma.
D) exceeds the partial pressure in the atmosphere.

Question 27

If the partial pressure of a substance in the atmosphere is 2x and the partial pressure of the same substance in the body fluid is 4x, the evaporation rate will

A) stay the same.
B) decrease.
C) increase.
D) cease.

Question 28

If the partial pressure of a substance in the atmosphere is 10 mmHg and the evaporation rate increases, then we can assume that the partial pressure of the same substance in the body fluid is _______ mmHg.

A) 1
B) 8
C) 10
D) 25

Question 29

Animal A has a body temperature of 35^°C and animal B has a body temperature of 40^°C. Both of the animals are in an environment at 40^°C and 25% relative humidity. Which of the two animals would lose more water?

A) Animal A because the air it exhales has more water vapor.
B) Animal B because the air it exhales has more water vapor.
C) Animal A because the air it inhales has more water vapor.
D) Animal B because the air it inhales has more water vapor.

Question 30

Refer to the formula shown.
With regard to terrestrial animals, the rate of evaporation, J, will increase if the distance of solution from air, X,

A) increases.
B) decreases.
C) does not change in value.
D) increases and then decreases.

Question 31

Refer to the formula shown.
The rate of evaporation, J, will increase if

A) WVP_s increases and WVP_a decreases.
B) WVP_s decreases and WVP_a increases.
C) WVP_s remains the same and WVP_a increases.
D) WVP_s decreases and WVP_a remains the same.

Question 32

Refer to the formula shown.
Which of the following will not increase the rate of evaporation, J?

A) An increase in K
B) An increase in WVP_s
C) A decrease in WVP_a
D) An increase in X

Question 33

Which animal has the lowest K value?

A) Reindeer
B) Lizard
C) Mouse
D) Frog

Question 34

Assuming humidity is the only factor that affects evaporation, which animal will have the highest rate of evaporation?

A) A mammal in a hot desert where humidity is very low
B) A mammal in a cold desert where humidity is very low
C) A lizard in a hot desert where humidity is very high
D) A lizard in a cold desert where humidity is very high

Question 35

At which temperature will an animal whose body surface temperature is 32^°C have the highest rate of condensation?

A) 28°C
B) 30°C
C) 31°C
D) 35°C

Question 36

Why do animals rarely gain water by condensation?

A) The animal's temperature is usually too cold.
B) The environmental humidity is almost never high enough.
C) The animal's temperature is usually too warm.
D) The environmental temperature is usually too high.

Question 37

Which of the following will most likely accompany evaporation?

A) The blood will become hypertonic.
B) The blood will become hypotonic.
C) The blood tonicity will not change.
D) The blood will become isotonic.

Question 38

The most fundamental function of the _______ is to prevent an animal from reaching an isosmotic line.

A) liver
B) small intestine
C) kidney
D) spleen

Question 39

In most aquatic animals, the organ whose function is equivalent to the mammalian kidney is the

A) kidney.
B) gill.
C) mantle.
D) aorta.

Question 40

An animal whose blood osmolarity is 100 mOsm and urine osmolarity is 80 mOSm will have _______ that is _______ to the plasma.

A) urine; hyperosmotic
B) urine; isosmotic
C) blood; hyperosmotic
D) blood; hyposmotic

Question 41

An animal whose blood osmolarity is 70 mOsm and urine osmolarity is 90 mOsm will have _______ that is _______ to the plasma.

A) urine; hyperosmotic
B) urine; isosmotic
C) blood; hyperosmotic
D) blood; hyposmotic

Question 42

The range of osmotic U/P ratio in humans is

A) 0.1 to 2.
B) 0.1 to 3.
C) 0.1 to 4.
D) 0.1 to 5.

Question 43

Urine that is hyposmotic to the blood plasma contains a

A) large amount of water.
B) normal amount of water.
C) low amount of water.
D) high amount of solutes and waste product.

Question 44

An ionic U/P ratio that is greater than 1 indicates that the urine contains

A) more sodium compared to the plasma.
B) less sodium compared to the plasma.
C) the same amount of sodium as the plasma does.
D) more sodium compared to the plasma, however, the concentration is equal.

Question 45

If a human drank sea water, ingestion of which ion would be most responsible for tissue dehydration?

A) Sodium
B) Potassium
C) Chloride
D) Magnesium

Question 46

Plants that tolerate and assimilate high concentrations of salt are called

A) bryophytes.
B) ferns.
C) halophytes.
D) stipes.

Question 47

Why might a seed-eating mouse in a desert benefit by storing seeds in its burrow prior to eating them.

A) The seeds could sprout in the burrow.
B) The seeds could absorb some water in the humid burrow.
C) The seeds could increase in fat content.
D) The seeds could lose salt in the burrow.

Question 48

You are trapped on a deserted island and are dehydrated and hungry. You have the ability to eat all the marine invertebrates you want or expend energy to catch a few fish. Which one is the better option in the long run?

A) Eat the invertebrates - you don't expend any energy to get them and they are similar in concentration to you so you will not dehydrate as much by eating them.
B) Eat the invertebrates - They contain less dehydrating proteins.
C) If you can catch the fish, they are similar in concentration to you so you will not dehydrate as much by eating them.
D) The fish are more nutritious so you should expend the energy to catch them.

Question 49

Water produced by cellular respiration is called _______ water.

A) catabolic
B) cellular respiration
C) preformed
D) metabolic

Question 50

Metabolic water is formed by

A) eating of food items with preformed water.
B) glycolysis.
C) the complete oxidation of glucose.
D) the Krebs cycle.

Question 51

Which substance results in water formation when consumed?

A) Proteins
B) Lipids
C) Carbohydrates
D) Both lipids and carbohydrates

Question 52

Which substance would cause the greatest loss of water when consumed?

A) Proteins, because they require urea for catabolism
B) Carbohydrates, because they generate carbon dioxide
C) Lipids, because they generate nitrogenous wastes
D) Proteins, because they generate urea

Question 53

Your friend is on a high-protein diet. As a result of the higher protein intake, your friend will most likely

A) lose water because water is important for protein storage.
B) gain water because water is produced by the breakdown of protein.
C) lose water because water is needed to excrete the excess urea produced from protein catabolism.
D) gain water because excess protein causes water storage.

Question 54

Kangaroo rats and laboratory rats differ in obligatory water loss via

A) respiration.
B) urine.
C) feces.
D) urine and feces.

Question 55

The fluid that directly bathes the cells is called

A) cytoplasm.
B) plasma.
C) extracellular fluid.
D) interstitial fluid.

Question 56

If cells are submerged in hypertonic solution they will

A) expand.
B) burst.
C) maintain the same volume.
D) shrivel.

Question 57

If the osmotic U/P ratio is greater than 1, and the plasma osmolarity is not adjusted to match the interstitial fluid osmolarity, there is an increased tendency for water to move

A) into cells, causing them to expand and eventually lyse.
B) out of cells, causing them to shrivel.
C) into cells, causing them to expand but not lyse since water will move out immediately.
D) out of cells, but the cells will not shrivel because water will move in immediately.

Question 58

If the osmotic U/P ratio is less than 1, and the plasma osmolarity is not adjusted to match the interstitial fluid osmolarity, there is an increased tendency for water to move

A) into cells, causing them to expand and eventually lyse.
B) out of cells, causing them to shrivel.
C) into cells, causing them to expand but not lyse since water will move out immediately.
D) out of cells, but the cells will not shrivel because water will move in immediately.

Question 59

Which collection of solutes, when dissolved in 100 ml of distilled water, exerts the highest osmotic pressure?

A) 1 mmol NaCl; 1mmol Mg²⁺
B) 2 mmol sucrose; 1 mmol Na⁺
C) 2 mmol glycine; 1 mmol taurine
D) 2 mmol arginine; 1 mmol NaCl

Question 60

In terms of osmotic pressure exerted, which comparison of dissolved chemicals is true?

A) 1 mmol taurine = 1 mmol Na⁺
B) 1mmol of glycine > 1 mmol NaCl
C) 1 mmol trimethylamine oxide > 1 mmol Na⁺
D) 1 mmol Mg²⁺ > 1 mmol Na⁺

Question 61

Refer to the figure shown.
The shaded area on the graph represents the

A) rate of enzyme catalysis.
B) normal enzyme substrate affinity.
C) normal range of osmolarity.
D) optimal metabolic rate.

Question 62

Refer to the figure shown.
In this figure, the solute that acts as a counteracting solute for urea is represented by the

A) middle line.
B) top line.
C) bottom line.
D) shaded area.

Question 63

Describe, in detail, how molting occurs in blue crabs.

Question 64

When blue crabs start the molting process, their bodies swell with water. Explain the significance of this swelling.

Question 65

Explain the importance of electrolytes in the body fluids.

Question 66

The rate of evaporation (J) depends on multiple factors. Define each factor and state how they are mathematically related.

Question 67

Explain what the osmotic U/P ratio is and what is indicated by different values.

Question 68

Explain how the kidneys in teleosts participate in ionic regulation but not osmotic regulation.

Question 69

Define and briefly explain obligatory respiratory water loss.

Question 70

Define and briefly explain the differences between obligatory urinary water loss and obligatory fecal water loss.

Question 71

In an environment in which the temperature is 25C, the relative humidity is 33%, the food available is air-dried barley grain, and there is no drinking water, a kangaroo rat will thrive, but a laboratory rat will not. Why?

Question 72

What are the mechanisms by which invertebrates' cells regulate the quantity of dissolved organic molecules in their intracellular fluid when they are transferred into ambient water with increased salinity?