Question 1

Which of the following best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

A double layer of phospholipids with proteins and cholesterol interspersed, allowing lateral movement of components.

Question 2

A red blood cell is placed in a solution and swells until it bursts. Which term best describes the tonicity of the solution, and what is the direction of water movement?

Accepted Answer

The solution is hypotonic; water moves into the cell.

Question 3

Which of the following best explains why facilitated diffusion differs from simple diffusion?

Accepted Answer

Facilitated diffusion uses carrier or channel proteins to move substances down their concentration gradient.

Question 4

A patient is given an intravenous solution with a higher concentration of nonpenetrating solutes than their blood plasma. What effect will this have on their red blood cells?

Accepted Answer

Cells will shrink as water leaves the cell to the hypertonic solution.

Question 5

Which of the following is a function of desmosomes in tissues such as the skin?

Accepted Answer

They provide mechanical coupling to resist tearing and stretching.

Question 6

Which equation best represents the relationship between osmolarity ($$O$$), the number of particles ($$n$$), and the molar concentration ($$C) of a $$solution?

Accepted Answer

$$O = n 	imes C$$

Question 7

A neuron maintains a resting membrane potential of $$-70\ \mathrm{mV}. $$Which ion is primarily responsible for establishing this potential, and what is the main mechanism?

Accepted Answer

Potassium ($$\mathrm{K}^+) $$via diffusion out of the cell through leak channels.

Question 8

Which of the following best describes the role of G protein-coupled receptors (GPCRs) in cell signaling?

Accepted Answer

They activate second messengers inside the cell in response to ligand binding.

Question 9

Which of the following processes requires energy input in the form of ATP?

Accepted Answer

Primary active transport of sodium and potassium ions.

Question 10

A cell engulfs a large bacterium by wrapping its plasma membrane around it and forming a vesicle. What is this process called?

Accepted Answer

Phagocytosis

Question 11

Which of the following best explains why the plasma membrane is described as selectively permeable?

Accepted Answer

It allows some substances to cross more easily than others.

Question 12

Which organelle is responsible for producing most of the ATP in a eukaryotic cell?

Accepted Answer

Mitochondrion

Question 13

A mutation causes a cell to lack functional peroxisomes. Which of the following would most likely be impaired?

Accepted Answer

Breakdown of hydrogen peroxide and fatty acids

Question 14

Which of the following best describes the function of the rough endoplasmic reticulum (RER)?

Accepted Answer

Synthesis of proteins for secretion or membrane insertion

Question 15

Which of the following is a correct sequence of events for receptor-mediated endocytosis?

Accepted Answer

Ligand binds receptor → vesicle forms → vesicle fuses with lysosome

Question 16

Which of the following best describes the function of the cytoskeleton?

Accepted Answer

It provides structural support, enables cell movement, and organizes organelles.

Question 17

A scientist observes that a cell is able to maintain a higher concentration of potassium ions ($$\mathrm{K}^+) $$inside than outside, and a higher concentration of sodium ions ($$\mathrm{Na}^+) $$outside than inside. Which transport protein is responsible for this distribution, and what is the equation for the number of ATP molecules hydrolyzed per cycle?

Accepted Answer

Sodium-potassium pump; $$1\ \mathrm{ATP}$$ hydrolyzed per cycle

Question 18

Which of the following is a key function of the glycocalyx on the surface of animal cells?

Accepted Answer

Acting as a biological marker for cell recognition

Question 19

Which of the following best describes the process of autophagy?

Accepted Answer

Packaging and degradation of damaged organelles within lysosomes

Question 20

A cell is exposed to a toxin that inhibits all forms of vesicular transport. Which of the following processes would be directly affected?

Accepted Answer

Phagocytosis of bacteria

Cell Structure and Function: Study Notes for Anatomy & Physiology

Guida di studio - Domande di pratica

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