Question 1

Which of the following best describes the difference between simple diffusion and facilitated diffusion across the plasma membrane?

Accepted Answer

Simple diffusion allows nonpolar, lipid-soluble substances to pass directly through the lipid bilayer, while facilitated diffusion requires carrier or channel proteins for hydrophilic molecules.

Question 2

A red blood cell is placed in a hypotonic solution. What is the most likely outcome for the cell?

Accepted Answer

The cell will swell and may burst due to water influx, a process called lysing.

Question 3

Which equation correctly represents the relationship between osmotic pressure ($\Pi$), molar concentration ($C$), gas constant ($R$), and temperature ($T$) for a dilute solution?

Accepted Answer

$\Pi = CRT$

Question 4

Which of the following molecules would most likely require a carrier protein for transport across the plasma membrane?

Accepted Answer

Glucose

Question 5

What is the primary function of a selectively permeable plasma membrane?

Accepted Answer

To regulate the entry and exit of specific substances, maintaining internal conditions.

Question 6

Which of the following scenarios best illustrates active transport?

Accepted Answer

Sodium ions ($Na^+$) are pumped out of a neuron against their concentration gradient using ATP.

Question 7

A cell is exposed to a hypertonic solution. What will happen to the cell and why?

Accepted Answer

Water will leave the cell, causing it to shrink (crenation) due to higher external osmolarity.

Question 8

Which process is responsible for the uptake of large particles, such as bacteria, by immune cells?

Accepted Answer

Phagocytosis

Question 9

Which of the following is NOT a survival need that must be maintained by homeostatic mechanisms?

Accepted Answer

Excessive atmospheric pressure

Question 10

In a negative feedback loop, what is the role of the effector?

Accepted Answer

To act on the variable and bring it closer to the set point.

Question 11

Which of the following is an example of a positive feedback mechanism in the human body?

Accepted Answer

Enhancement of labor contractions by oxytocin.

Question 12

Which statement best describes the difference between regulators and conformers in animal physiology?

Accepted Answer

Regulators use internal mechanisms to control internal change despite external fluctuations, while conformers allow internal conditions to change with the environment.

Question 13

Which of the following best illustrates a feedforward (anticipatory) response?

Accepted Answer

Release of saliva and digestive juices in response to the smell of food before ingestion.

Question 14

Which of the following is true about hormones and their effects on target cells?

Accepted Answer

Only cells with specific receptors for a hormone can respond, and hormones may have multiple effects depending on the target cell.

Question 15

Which process requires ATP to move substances across the plasma membrane?

Accepted Answer

Active transport

Question 16

Which of the following is a function of the nervous system in coordinating animal physiology?

Accepted Answer

Transmitting signals along dedicated routes to specific locations in the body.

Question 17

A fish living in cold water is found to regulate the solute concentration in its blood but not its body temperature. What does this indicate about the fish?

Accepted Answer

It is a regulator for solute concentration and a conformer for temperature.

Question 18

Which of the following is NOT a type of vesicular transport?

Accepted Answer

Simple diffusion

Question 19

Which of the following best describes the effect of an isotonic solution on animal cells?

Accepted Answer

Cells maintain their normal shape and volume.

Question 20

Which of the following is a correct sequence for a simple endocrine pathway?

Accepted Answer

Stimulus → Endocrine cell → Hormone release → Target cell response

Cell Membrane Transport and Homeostasis: Key Concepts for Anatomy & Physiology

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