Question 1

Bushmen hunters exploit the effects of physiological stress by forcing their prey to run when the temperature exceeds the animal's core temperature.

Accepted Answer

This is true. Bushmen hunters are known to force their prey, such as antelopes, to run during the hottest part of the day when the temperature exceeds the animal's core temperature. This causes the animal to experience physiological stress and can result in exhaustion, making it easier for the hunter to catch the animal.

Question 2

When does water stop moving by osmosis between two areas of different solute concentration?

Accepted Answer

Osmosis continues until the osmotic pressure, which is a measure of the solute concentration difference, is balanced by the hydrostatic pressure, which is the pressure exerted by the weight of the fluid. At this point, the flow of water stops and the solutions reach equilibrium. Therefore, only option C correctly describes the point at which water stops moving by osmosis.

Question 3

Depending on their environments, animals may gain electrolytes:

Accepted Answer

Animals can gain electrolytes from food, seawater, and through gills and skin. Electrolytes are important for maintaining proper hydration, nerve function, and muscle function in animals. While cellular respiration and exposure to ultraviolet light may have other physiological effects, they do not play a direct role in the acquisition of electrolytes.

Question 4

Examine Figure 41.1. As water flows into the region with high solute concentration, it exerts an opposing force called _____ pressure, which eventually prevents additional water from moving into the compartment, bringing the system into equilibrium.

Accepted Answer

The answer of Examine Figure 41.1. As water flows into...

Question 5

Depending on their environments, animals may gain water:

Accepted Answer

The answer of Depending on their environments, animals may gain...

Question 6

In organisms, the ability to control osmosis depends on the properties of the plasma membranes of individual cells. Based on their ability to permit the free movement of water and some solutes, these membranes are described as:

Accepted Answer

The term used to describe the ability of plasma membranes to allow for the selective movement of water and some solutes is selectively permeable. The term permeable alone implies that all substances can pass through freely, which is not the case for plasma membranes. Impermeable and impervious both suggest that no substances can pass through, which is also not accurate. Diffusible is not a term typically used to describe plasma membranes in this context.

Question 7

You have 1 L of 2 mM uric acid. Conditions change in such a way that all the uric acid precipitates out of solution. What is the final concentration of uric acid in your solution?

Accepted Answer

If all the uric acid precipitates out of solution, then there is no uric acid left in solution. Therefore, the final concentration is 0 mM.

Question 8

What would happen if you placed a trout (a freshwater fish) into a saltwater tank at the aquarium and made some observations?

Accepted Answer

Placing a freshwater fish in a saltwater tank would cause water to move out of the fish's cells by osmosis due to the higher concentration of salt in the tank compared to the fish's cells. This would cause the fish to lose water and potentially lead to dehydration and death if not addressed. The fish would not be able to adapt quickly enough to the changes in their body's ion concentration to reverse the direction of ion movement to deal with excess water.

Question 9

Depending on their environments, animals may lose water:

Accepted Answer

The answer of Depending on their environments, animals may lose...

Question 10

To counter the ingestion of excess salts, marine teleost fish have specialized cells in their gills that pump _____ ions into the surrounding seawater. As these ions leave the fishes' bodies, they create an electrical gradient that is balanced when _____ ions leave their bodies as well.

Accepted Answer

Marine teleost fish have specialized cells in their gills that pump chloride ions into the surrounding seawater to counter the ingestion of excess salts. As chloride ions leave, they create an electrical gradient that is balanced when sodium ions also leave their bodies, maintaining osmotic balance.

Question 11

Freshwater fish are in a hypotonic environment. How do their gill chloride cells function in this environment?

Accepted Answer

The answer of Freshwater fish are in a hypotonic environment....

Question 12

The excretory organs of different organisms are extremely varied. What do all excretory organs have in common?

Accepted Answer

All excretory organs have a filtration system that filters nitrogenous waste from the body fluids. Nitrogenous waste, such as ammonia or urea, is produced as a result of amino acid metabolism and must be eliminated from the body in order to prevent toxicity.

Question 13

Despite being an osmoconformer, a shark still spends energy to regulate the concentrations of individual ions such as potassium, chloride, and sodium.

Accepted Answer

Even though sharks are osmoconformers and do not actively regulate their internal salt concentrations to match that in the environment, they still require energy to regulate the concentrations of individual ions such as potassium, chloride, and sodium. This is because the concentrations of these ions vary in the environment and within the animal's body, and maintaining the appropriate levels for proper physiological functioning requires energy expenditure.

Question 14

Depending on their environments, animals may lose electrolytes:

Accepted Answer

The answer of Depending on their environments, animals may lose...

Question 15

Examine Figure 41.1. Which of the following BEST describes conditions at equilibrium?

Accepted Answer

At equilibrium, the concentration of water molecules is the same on both sides of the barrier. However, this does not mean that there is no movement of water molecules. Instead, water molecules move randomly across the barrier but the net movement is zero because the concentration is the same on both sides. Therefore, the correct answer is D.

Question 16

Water molecules move by:

Accepted Answer

The answer of Water molecules move by:
...

Question 17

Osmoconformers tend to live in environments with variable solute concentrations.

Accepted Answer

Osmoconformers typically live in stable environments with constant solute concentrations, as their internal solute concentration varies with that of their environment.

Question 18

Marine fish:

Accepted Answer

The answer of Marine fish:
...

Question 19

Fish in a marine environment must maintain a relatively constant ion concentration in their tissues and blood. How do the chloride cells in the gills aid fish in the removal of excess ions?

Accepted Answer

Chloride cells in the gills of fish actively remove ions from the body to maintain ion concentration, and water follows these ions by osmosis, helping to regulate the internal environment of the fish.

Question 20

Bushmen hunters avoid the effects of physiological stress during prolonged hunts by increasing their carbohydrate intake as much as possible before the hunt.

Accepted Answer

Bushmen hunters manage the effects of physiological stress during prolonged hunts primarily through their exceptional endurance and tracking skills, not by specifically increasing their carbohydrate intake before the hunt.

Quiz 41: Animal Renal Systems: Water and Waste