Lecture 11 Osmoregulation Part 1

Question 1

Which of the following statements correctly describes osmosis?
a) The movement of water from an area of higher solute concentration to lower solute concentration.
b) The movement of any substance across a semi-permeable membrane.
c) The movement of water from an area of lower solute concentration to higher solute concentration.
d) The movement of solutes through a membrane from high to low concentration.

Answer 1

Answer: c) The movement of water from an area of lower solute concentration to higher solute concentration.

Question 2

Osmotic pressure increases when:
a) The solute concentration decreases.
b) The solute concentration increases.
c) Water moves to an area of lower osmotic pressure.
d) There is no solute in the solution.

Answer 2

Answer: b) The solute concentration increases.

Question 3

Freshwater fish experience which of the following challenges in osmoregulation?
a) Losing water and gaining salts.
b) Gaining water and losing salts.
c) Maintaining the same osmolarity as their environment.
d) Excreting large amounts of concentrated urine.

Answer 3

Answer: b) Gaining water and losing salts.

Question 4

If you dissolve 1 mole of NaCl in 1 liter of water, the resulting osmolarity is:
a) 1 osmolar.
b) 2 osmolar.
c) 0.5 osmolar.
d) Cannot be determined without more information.

Answer 4

Answer: b) 2 osmolar.

Question 5

A fish is placed in a tank with a solution that has higher solute concentration than its body fluids. Predict the direction of water movement and explain what happens to the fish.

Answer 5

Solution:
Water will move out of the fish (from lower solute concentration inside the fish to higher solute concentration in the tank). This will cause the fish to lose water and potentially shrivel if it cannot regulate the water loss.

Question 6

A freshwater fish is accidentally placed in saltwater. What will happen to the fish, and why?

Answer 6

Saltwater has a higher solute concentration (higher osmotic pressure) than the fish’s body fluids.
Water will move out of the fish into the saltwater, causing the fish to dehydrate and potentially die if it cannot adjust.

Question 7

Approximately what percentage of the human adult body is water?
a) 30%
b) 60%
c) 75%
d) 95%

Answer 7

Answer: b) 60%

Question 8

Which of the following is NOT a major fluid compartment in the body?
a) Intracellular fluid
b) Extracellular fluid
c) Plasma
d) Bone marrow

Answer 8

d) Bone MArrow

Question 9

Which of the following are components of extracellular fluid?
a) Cytoplasm and interstitial fluid
b) Blood plasma and interstitial fluid
c) Intracellular fluid and cytoplasm
d) Interstitial fluid and cytoplasm

Answer 9

Answer: b) Blood plasma and interstitial fluid

Question 10

What separates interstitial fluid from blood plasma?
a) Cell membranes
b) Endothelial cells of capillary walls
c) Cytoplasmic membranes
d) Intercellular junctions

Answer 10

Answer: b) Endothelial cells of capillary walls

Question 11

Which of the following is NOT a major component of body fluids?
a) Water
b) Large molecules like carbohydrates and proteins
c) Electrolytes
d) Lipids as the primary matrix of the solution

Answer 11

Answer: d) Lipids as the primary matrix of the solution

Question 12

Where is the concentration of sodium (𝑁𝑎+ ) highest?

a) Intracellular fluid
b) Blood plasma and interstitial fluid
c) Cytoplasm
d) Inside the nucleus

Answer 12

Answer: b) Blood plasma and interstitial fluid

Question 13

What is the primary role of water in body fluids?
a) Acts as a structural component for cells.
b) Serves as the matrix in which solutes dissolve and influences cell volume.
c) Provides energy for cellular activities.
d) Acts as a barrier to ion movement.

Answer 13

Answer: b) Serves as the matrix in which solutes dissolve and influences cell volume.

Question 14

Which statement about potassium (𝐾+) is correct?

a) It is higher in the extracellular fluid compared to intracellular fluid.
b) It is higher in the intracellular fluid compared to extracellular fluid.
c) Its concentration is equal in all compartments.
d) It is mostly bound to proteins in the blood plasma.

Answer 14

b)

Question 15

Which of the following is NOT considered a large molecule in body fluids?
a) Proteins
b) Fatty acids
c) Sodium ions
d) Carbohydrates

Answer 15

Answer: c) Sodium ions

Question 16

Which of the following is NOT a type of fluid regulation?
a) Osmotic regulation
b) Ionic regulation
c) Volume regulation
d) Pressure regulation

Answer 16

Answer: d) Pressure regulation

Question 17

What problem do freshwater fish face with osmoregulation?
a) Losing water and gaining salts
b) Gaining water and losing salts
c) Maintaining equal osmotic pressure as their environment
d) Preventing water loss due to evaporation

Answer 17

Answer: b) Gaining water and losing salts

Question 18

What is the primary osmoregulatory challenge for saltwater fish?
a) Gaining water and swelling
b) Losing water and gaining salts
c) Maintaining isotonic balance with their environment
d) Preventing ion loss

Answer 18

Answer: b) Losing water and gaining salts

Question 19

Which of the following statements about diffusion and osmosis is TRUE?
a) Diffusion only occurs with water molecules, while osmosis involves any solute.
b) Osmosis depends on solute differences and is specific to water, while diffusion depends on concentration gradients of any substance.
c) Diffusion is active, while osmosis is passive.
d) Osmosis occurs in both permeable and non-permeable membranes.

Answer 19

Answer: b) Osmosis depends on solute differences and is specific to water, while diffusion depends on concentration gradients of any substance.

Question 20

In osmosis, water moves:
a) From higher solute concentration to lower solute concentration.
b) From lower solute concentration to higher solute concentration.
c) From hypertonic solutions to hypotonic solutions.
d) In random directions regardless of solute concentration.

Answer 20

Answer: b) From lower solute concentration to higher solute concentration.

Question 21

Osmosis depends on:
a) The number of solute particles in the solution.
b) The specific type of solute in the solution.
c) The permeability of solutes through the membrane.
d) The temperature of the solution alone.

Answer 21

Answer: a) The number of solute particles in the solution.

Question 22

How does diffusion differ from osmosis?
a) Diffusion only involves water, while osmosis involves any substance.
b) Osmosis is active, requiring channels, while diffusion is passive.
c) Diffusion does not require a membrane, while osmosis occurs across a semi-permeable membrane.
d) Diffusion depends on solute size, while osmosis depends on temperature.

Answer 22

Answer: c) Diffusion does not require a membrane, while osmosis occurs across a semi-permeable membrane.

Question 23

Which fish would be more prone to swelling due to water gain?
a) Freshwater fish
b) Saltwater fish
c) Both freshwater and saltwater fish equally
d) Neither freshwater nor saltwater fish

Answer 23

Answer: a) Freshwater fish

Question 24

The regulation of body fluids involves:
a) Movement of ions and water, but not total volume.
b) Movement of water, ions, and changes in total volume.
c) Changes in only water content, with no ion involvement.
d) Passive osmoregulation only, without energy use.

Answer 24

Answer: b) Movement of water, ions, and changes in total volume.

Question 25

Colligative properties depend on:
a) The number of solute particles in a solution.
b) The type of solute dissolved in the solution.
c) The temperature of the solution.
d) The chemical nature of the solute particles.

Answer 25

Answer: a) The number of solute particles in a solution.

Question 26

Which of the following is NOT a colligative property?
a) Osmotic pressure
b) Freezing point
c) Water vapor pressure
d) Density of the solution

Answer 26

Answer: d) Density of the solution.

Question 27

What causes an increase in osmotic pressure?
a) A decrease in solute concentration.
b) An increase in solute concentration.
c) The chemical nature of the solute.
d) Lower temperature of the solution.

Answer 27

Answer: b) An increase in solute concentration.

Question 28

What happens to the freezing point of a solution as the number of solute particles increases?
a) It increases.
b) It decreases.
c) It remains unchanged.
d) It depends on the type of solute.

Answer 28

Answer: b) It decreases.

Question 29

Which of the following explains why the freezing point of two solutions with the same number of solute particles is the same, regardless of the solute type?
a) Freezing point is a colligative property dependent only on the number of solute particles.
b) Freezing point depends on the chemical identity of the solute particles.
c) Freezing point depends on temperature and solute size.
d) Freezing point depends on the polarity of the solute particles.

Answer 29

Answer: a) Freezing point is a colligative property dependent only on the number of solute particles.

Question 30

If Solution 1 has 2 moles of NaCl and Solution 2 has 2 moles of glucose dissolved in 1 liter of water, which statement is correct?
a) Solution 1 has higher osmotic pressure because NaCl dissociates into more particles.
b) Solution 2 has higher osmotic pressure because glucose is a larger molecule.
c) Both solutions have the same osmotic pressure.
d) Osmotic pressure depends on the molecular weight of the solute.

Answer 30

Answer: a) Solution 1 has higher osmotic pressure because NaCl dissociates into more particles.

Question 31

A solution with a higher number of dissolved solute particles will:
a) Increase the water vapor pressure.
b) Decrease the water vapor pressure.
c) Have no effect on the water vapor pressure.
d) Increase the water vapor pressure at higher temperatures only.

Answer 31

Answer: b) Decrease the water vapor pressure.

Question 32

Why do colligative properties depend only on the number of solute particles?
a) Because the chemical interactions between solute particles are ignored.
b) Because the solvent molecules interact equally with all solute types.
c) Because solute particles disrupt the equilibrium properties of the solvent.
d) Because colligative properties are based only on volume.

Answer 32

Answer: c) Because solute particles disrupt the equilibrium properties of the solvent.

Question 33

Why does a 1 M NaCl solution exhibit a higher osmotic pressure than a 1 M glucose solution?
a) NaCl dissociates into more particles in solution.
b) Glucose molecules are larger than NaCl molecules.
c) NaCl is more soluble than glucose.
d) Glucose cannot affect osmotic pressure.

Answer 33

Answer: a) NaCl dissociates into more particles in solution.

Question 34

Which of the following is an application of colligative properties?
a) Adding salt to ice to lower its freezing point.
b) Dissolving sugar to change the color of water.
c) Using large solutes to increase the density of a solution.
d) Increasing solubility by raising the temperature.

Answer 34

Answer: a) Adding salt to ice to lower its freezing point.

Question 35

What drives the movement of water in osmosis?
a) Water moves from high solute concentration to low solute concentration.
b) Water moves from high osmotic pressure to low osmotic pressure.
c) Water moves from low osmotic pressure to high osmotic pressure.
d) Water moves randomly, regardless of solute concentration.

Answer 35

Answer: c) Water moves from low osmotic pressure to high osmotic pressure.

Question 36

What happens to osmotic pressure as solute concentration increases?
a) It decreases.
b) It remains constant.
c) It increases.
d) It depends on the solvent.

Answer 36

Answer: c) It increases.

Question 37

In osmosis, water flows:
a) From a hypertonic solution to a hypotonic solution.
b) From a hypotonic solution to a hypertonic solution.
c) From high solute concentration to low solute concentration.
d) Between two solutions of equal solute concentrations.

Answer 37

Answer: b) From a hypotonic solution to a hypertonic solution.

Question 38

Why do freshwater fish tend to swell with water?
a) Water has higher osmotic pressure than the fish.
b) The fish has a higher solute concentration than the water.
c) Water has a lower solute concentration than the fish.
d) The fish’s osmotic pressure is higher than the water’s.

Answer 38

Answer: b) The fish has a higher solute concentration than the water.

Question 39

What is the primary osmotic challenge for saltwater fish?
a) Gaining water due to high osmotic pressure in their environment.
b) Losing water due to high osmotic pressure in their environment.
c) Maintaining isotonic balance with their surroundings.
d) Preventing excess salt loss.

Answer 39

Answer: b) Losing water due to high osmotic pressure in their environment.

Question 40

What is the osmolarity of a 1 M NaCl solution?
a) 1 osmolar
b) 2 osmolar
c) 0.5 osmolar
d) 3 osmolar

Answer 40

Answer: b) 2 osmolar

Question 41

What happens when osmotic pressure equals hydrostatic pressure?
a) Water movement stops.
b) Water flows from low to high osmotic pressure.
c) Solutes move instead of water.
d) Water moves against its concentration gradient.

Answer 41

Answer: a) Water movement stops.

Question 42

Osmotic Regulation in River Fish
If a fish lives in the Otonabee River (freshwater), what happens to water movement across its gills?

a) Water flows out of the fish because its osmotic pressure is lower than the river’s.
b) Water flows into the fish because its osmotic pressure is higher than the river’s.
c) Water flows equally in and out of the fish due to isotonic conditions.
d) Water movement stops because the solute concentrations are equal.

Answer 42

Answer: b) Water flows into the fish because its osmotic pressure is higher than the river’s.

Question 43

If a selectively permeable membrane separates two solutions, one with high solute concentration and one with low solute concentration, what occurs?
a) Water moves from high solute to low solute concentration.
b) Solutes move from low to high concentration.
c) Water moves from low solute to high solute concentration.
d) No movement occurs because of the membrane.

Answer 43

Answer: c) Water moves from low solute to high solute concentration.

Question 44

Osmotic pressure is best described as:
a) The force driving solute movement between two solutions.
b) The force preventing water movement in osmosis.
c) The pressure required to stop water from moving by osmosis.
d) The energy needed to dissolve solutes in a solution.

Answer 44

answer: c) The pressure required to stop water from moving by osmosis.