Question 1

Which of the following best describes the structure of the cell membrane according to the fluid mosaic model?

Accepted Answer

A double layer (bilayer) of phospholipids with proteins and carbohydrates dispersed throughout.

Question 2

Which type of feedback loop is primarily responsible for maintaining homeostasis in the human body?

Accepted Answer

Negative feedback loop

Question 3

During a negative feedback loop regulating blood glucose, which organ acts as the sensor detecting changes in glucose concentration?

Accepted Answer

Pancreas

Question 4

Which of the following is NOT a function of the cell membrane?

Accepted Answer

Production of ATP

Question 5

A patient is experiencing a rapid increase in blood pressure. Which control system component is responsible for detecting this change?

Accepted Answer

Baroreceptor

Question 6

Which lipid type is most responsible for increasing membrane viscosity and decreasing permeability?

Accepted Answer

Cholesterol

Question 7

If a cell membrane contains a high percentage of proteins, what can be inferred about its metabolic activity?

Accepted Answer

It is more metabolically active.

Question 8

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

Accepted Answer

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

Question 9

Which of the following is a real-life example of a positive feedback loop in the human body?

Accepted Answer

Release of oxytocin during childbirth to intensify uterine contractions

Question 10

A cell membrane contains glycoproteins and glycolipids on its surface. What is their primary role?

Accepted Answer

Cell-to-cell recognition and communication

Question 11

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

Accepted Answer

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

Question 12

Which of the following statements about lipid rafts is correct?

Accepted Answer

They are areas with high concentrations of proteins important in cell signaling.

Question 13

Which type of membrane protein is most likely to participate in intracellular signaling?

Accepted Answer

Transmembrane proteins

Question 14

A feedforward control system is best described as:

Accepted Answer

A system that anticipates a change and initiates a response before the change occurs.

Question 15

Which of the following is a correct sequence of events in a reflex control system regulating blood pressure?

Accepted Answer

Baroreceptor detects stretch → Signal sent to CNS → CNS sends signal to target tissue

Question 16

Which of the following best describes the role of carbohydrates in the cell membrane?

Accepted Answer

They serve as recognition sites for cell signaling.

Question 17

Which of the following is true regarding the distribution of proteins in cell membranes?

Accepted Answer

The more metabolically active a membrane, the more proteins it contains.

Question 18

Which of the following is a function of integral (transmembrane) proteins?

Accepted Answer

Participating in cell adhesion and signaling

Question 19

A patient with a genetic mutation affecting sphingolipids in the cell membrane would most likely have defects in which membrane structure?

Accepted Answer

Lipid rafts

Question 20

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

Accepted Answer

They drive the system away from a normal value, amplifying the original stimulus.

Cell Membranes and Control Systems: Structure, Function, and Homeostasis CM1

Study Guide - Practice Questions