Question 1

Which of the following best describes the structure of the major lipid found in cell membranes?

Accepted Answer

A phospholipid with a hydrophilic head and two hydrophobic fatty acid tails.

Question 2

A red blood cell is placed in a solution and begins to swell and eventually bursts. Which term best describes the solution, and what is the direction of water movement?

Accepted Answer

Hypotonic; water moves into the cell.

Question 3

Which of the following statements about passive and active transport across the plasma membrane is correct?

Accepted Answer

Passive transport moves substances down their concentration gradient without energy input.

Question 4

Which factor would most likely increase the selective permeability of a cell membrane to small, nonpolar molecules?

Accepted Answer

Increasing the proportion of unsaturated fatty acids in the membrane.

Question 5

A scientist observes a cell with a nucleus, mitochondria, and endoplasmic reticulum. Which type of cell is this, and what is a key difference from prokaryotic cells?

Accepted Answer

Eukaryotic; it contains membrane-bound organelles.

Question 6

According to the endosymbiotic theory, which organelle is believed to have originated from a free-living prokaryote engulfed by an ancestral eukaryotic cell?

Accepted Answer

Mitochondrion

Question 7

Which cytoskeletal component is primarily responsible for the movement of cilia and flagella in eukaryotic cells?

Accepted Answer

Microtubules

Question 8

A protein is synthesized in the rough endoplasmic reticulum (ER). Which sequence correctly describes its path to secretion outside the cell?

Accepted Answer

Rough ER → Golgi apparatus → plasma membrane

Question 9

Which of the following best explains how plant cells are connected and communicate with each other?

Accepted Answer

Via plasmodesmata, which are channels through the cell wall.

Question 10

A hormone is lipid-soluble. How does it typically influence target cells?

Accepted Answer

It diffuses through the plasma membrane and binds to intracellular receptors.

Question 11

Which of the following is a correct example of signal transduction involving a second messenger?

Accepted Answer

A peptide hormone binding to a cell surface receptor, leading to the production of cyclic AMP ($$cAMP) $$inside the cell.

Question 12

Which equation best represents the net movement of water across a selectively permeable membrane due to osmosis?

Accepted Answer

$$ \Delta \Psi = \Psi_s + \Psi_p $$

Question 13

Which of the following is a function of the extracellular matrix (ECM) in animal tissues?

Accepted Answer

It provides structural support and helps cells adhere to one another.

Question 14

A mutation causes a cell to lack functional lysosomes. Which process would be most directly affected?

Accepted Answer

Intracellular digestion of macromolecules

Question 15

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

Accepted Answer

It stabilizes membrane fluidity across temperature changes.

Question 16

A cell is placed in a hypertonic solution. What will most likely happen to the cell?

Accepted Answer

It will lose water and shrink.

Question 17

Which of the following is NOT a function of the cytoskeleton?

Accepted Answer

Synthesizing DNA

Question 18

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

Accepted Answer

It contains a variety of proteins and lipids that can move laterally within the layer.

Question 19

Which of the following best describes how gap junctions function in animal cells?

Accepted Answer

They allow direct passage of ions and small molecules between adjacent cells.

Unit 2 - Cells: Structure, Function, and Communication

Guida di studio - Domande di pratica

Study guide - Flashcard