Question 1

Which of the following best describes the function of cholesterol in the plasma membrane?

Accepted Answer

It immobilizes the first few hydrocarbon groups of phospholipids, making the membrane less deformable and decreasing permeability to small water-soluble molecules.

Question 2

A patient has a genetic defect that prevents the formation of tight junctions in their intestinal epithelium. Which of the following is the most likely consequence?

Accepted Answer

Increased movement of materials between adjacent cells, leading to compromised barrier function.

Question 3

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

Accepted Answer

Synthesizing DNA for cell division.

Question 4

Which of the following best explains why the lumen of the digestive tract is considered part of the external environment?

Accepted Answer

Because substances in the lumen have not yet crossed an epithelial barrier to enter the internal environment.

Question 5

Which of the following correctly matches the tissue type with its primary function?

Accepted Answer

Muscle tissue: Contracts to cause movement

Question 6

A researcher is studying a protein that spans the entire plasma membrane and allows ions to pass through. This protein is best classified as:

Accepted Answer

A transmembrane (integral) protein

Question 7

Which of the following best describes the structure of a phospholipid molecule in the plasma membrane?

Accepted Answer

Two fatty acid chains bound to glycerol with a phosphate group, forming a bilayer with hydrophobic tails inward and hydrophilic heads outward.

Question 8

Gap junctions are important in cardiac muscle because they:

Accepted Answer

Allow chemical and electrical signals to pass directly from cell to cell, enabling coordinated contraction.

Question 9

Which of the following is a correct sequence for the synthesis and packaging of a secreted protein?

Accepted Answer

Ribosome → Endoplasmic reticulum → Golgi apparatus → Vesicle

Question 10

A mutation disrupts the function of kinesin motor proteins in a neuron. Which cellular process would be most directly affected?

Accepted Answer

Anterograde transport of vesicles along microtubules from the nucleus toward the axon terminal.

Question 11

Which of the following best describes the role of the basement membrane in epithelial tissue?

Accepted Answer

It anchors epithelial cells to underlying connective tissue, providing structural support.

Question 12

Which of the following is a key difference between desmosomes and tight junctions?

Accepted Answer

Desmosomes provide strong anchoring between cells, while tight junctions prevent movement of materials between cells.

Question 13

A scientist is studying a tissue that lines the inside of blood vessels and releases substances to regulate vascular relaxation and contraction. This tissue is most likely:

Accepted Answer

Endothelium, a specialized type of epithelial tissue.

Question 14

Which of the following best explains why the plasma membrane is described as a 'fluid mosaic'?

Accepted Answer

Because it consists of a bilayer of lipids with proteins and other molecules that can move laterally within the layer.

Question 15

Which of the following components is NOT a major part of the plasma membrane?

Accepted Answer

DNA

Question 16

A patient is diagnosed with a disease that affects the assembly of microtubules. Which of the following cellular processes is most likely to be impaired?

Accepted Answer

Intracellular transport of vesicles and organelles.

Question 17

Which of the following equations best represents the relationship between the surface area ($$A) $$and volume ($$V) of a $$spherical cell of radius $$r$$?

Accepted Answer

$$A = 4\pi r^2$, V$$ = \frac{4}{3}\pi $$r^3$$

Question 18

Which of the following best describes the function of the nuclear envelope?

Accepted Answer

It separates the nucleus from the cytoplasm and contains pores to allow communication between the two.

Question 19

Which of the following statements about homeostasis and feedback mechanisms is correct?

Accepted Answer

Negative feedback opposes changes in a controlled variable, helping to maintain stability.

Compartmentation: Cells and Tissues – Study Notes for Animal Physiology

Guida di studio - Domande di pratica

Study guide - Flashcard