Question 1

Which of the following best describes the primary function of the cell membrane in maintaining homeostasis?

Accepted Answer

It selectively controls the exchange of materials between the intracellular and extracellular environments.

Question 2

A patient with a genetic mutation affecting cholesterol synthesis is found to have cell membranes that are less viscous and more permeable. Which membrane property is most directly affected by the lack of cholesterol?

Accepted Answer

Decreased membrane fluidity and increased permeability

Question 3

Which of the following is NOT a component of the fluid mosaic model of the cell membrane?

Accepted Answer

Cellulose fibers

Question 4

During a negative feedback loop regulating blood glucose, which of the following events occurs after insulin is released?

Accepted Answer

Cells take up glucose, lowering blood glucose levels

Question 5

Which equation best represents the relationship between membrane permeability ($P$), membrane thickness ($d$), and diffusion coefficient ($D$)?

Accepted Answer

$P = \frac{D}{d}$

Question 6

A researcher observes that certain regions of the cell membrane are more viscous and contain higher concentrations of cholesterol and sphingolipids. What are these regions called?

Accepted Answer

Lipid rafts

Question 7

Which of the following best explains why phospholipids form bilayers in aqueous environments?

Accepted Answer

Their hydrophobic tails avoid water while hydrophilic heads interact with water.

Question 8

Which type of membrane protein is most likely to function as a channel for ions to cross the cell membrane?

Accepted Answer

Transmembrane protein

Question 9

A patient is experiencing rapid blood loss, which triggers a positive feedback loop. Which of the following best describes the outcome of this loop?

Accepted Answer

The response amplifies the initial stimulus, potentially leading to a dangerous state.

Question 10

Which of the following is a real-life example of a feedforward control system in human physiology?

Accepted Answer

Salivation in anticipation of food

Question 11

Which of the following statements about cell membrane proteins is correct?

Accepted Answer

Peripheral proteins are loosely attached to the membrane and often participate in intracellular signaling.

Question 12

If a cell membrane contains 40% proteins, 55% lipids, and 5% carbohydrates, which component is most likely to increase in membranes with higher metabolic activity?

Accepted Answer

Proteins

Question 13

Which of the following best describes the role of glycoproteins and glycolipids on the cell membrane?

Accepted Answer

They are involved in cell-to-cell recognition and communication.

Question 14

A cell is exposed to a toxin that disrupts the function of its membrane proteins. Which process is most likely to be directly affected?

Accepted Answer

Transport of ions and molecules across the membrane

Question 15

Which of the following is true regarding the setpoint in physiological control systems?

Accepted Answer

It is a value around which a variable is regulated, but can vary between individuals.

Question 16

Which of the following best explains why positive feedback loops are generally not homeostatic?

Accepted Answer

They amplify the initial stimulus rather than opposing it.

Question 17

Which of the following membrane components is most directly responsible for anchoring the cytoskeleton to the cell membrane?

Accepted Answer

Integral proteins

Question 18

A person’s body temperature follows a circadian rhythm. Which of the following best describes this phenomenon?

Accepted Answer

Body temperature fluctuates in a predictable pattern over a 24-hour cycle.

Question 19

Which of the following is a correct statement about the role of carbohydrates in the cell membrane?

Accepted Answer

They are primarily found attached to proteins and lipids on the extracellular surface.

Question 20

Which of the following best describes the difference between local and reflex control systems?

Accepted Answer

Local control is restricted to a small region, while reflex control is systemic and involves the nervous and/or endocrine systems.

Cell Membranes and Control Systems in Anatomy & Physiology

Study Guide - Practice Questions

Study Guide - Flashcards