$$\text{Signal} \rightarrow n \times \text{Second Messenger}$$

Question 1

Which of the following best describes the primary structural component of the extracellular matrix (ECM) in animal cells?

Accepted Answer

Collagen fibrils

Question 2

What is the main function of proteoglycans in the ground substance of the ECM?

Accepted Answer

To give cartilage its rubber-like consistency

Question 3

Which structure is responsible for gluing adjacent plant cells together?

Accepted Answer

Middle lamella

Question 4

Tight junctions are most likely to be found in which type of tissue?

Accepted Answer

Epithelial tissue

Question 5

Which of the following best explains why ions can rapidly move between adjacent animal cells in cardiac muscle?

Accepted Answer

Presence of gap junctions

Question 6

A mutation disrupts the formation of cytoskeletal intermediate filaments in epithelial cells. Which cell–cell attachment would be most affected?

Accepted Answer

Desmosomes

Question 7

Which of the following is TRUE about plasmodesmata in plant cells?

Accepted Answer

They allow the plasma membrane, cytoplasm, and smooth ER to connect between cells.

Question 8

Which of the following best describes the difference between the symplast and apoplast in plant tissues?

Accepted Answer

Symplast is the shared cytoplasm; apoplast is the extracellular space.

Question 9

A hormone is secreted by a cell and travels through the bloodstream to affect distant target cells. This is an example of:

Accepted Answer

Endocrine signaling

Question 10

Which of the following is a key feature of G-protein-coupled receptor (GPCR) signaling?

Accepted Answer

Initiation of a second messenger cascade

Question 11

Which process is responsible for amplifying an extracellular signal inside a cell?

Accepted Answer

Signal transduction

Question 12

Which of the following best describes the role of enzyme-linked receptors in cell signaling?

Accepted Answer

They phosphorylate proteins inside the target cell.

Question 13

A researcher observes that a signaling pathway is less effective when a second pathway is simultaneously activated. This is most likely due to:

Accepted Answer

Crosstalk between signaling pathways

Question 14

Which of the following scenarios best illustrates the function of tight junctions in the human body?

Accepted Answer

Preventing leakage of digestive enzymes between intestinal epithelial cells

Question 15

If a mutation caused the loss of pectins in the middle lamella, what would be the most likely consequence for plant cells?

Accepted Answer

Cells would not adhere properly to each other.

Question 16

Which of the following best explains why cartilage is more flexible than bone?

Accepted Answer

Cartilage has a ground substance rich in proteoglycans.

Question 17

Which of the following equations best represents the amplification of a signal in a second messenger cascade?

Accepted Answer

$$	ext{Signal} ightarrow n 	imes 	ext{Second Messenger}$$

Question 18

Which of the following is NOT a function of the extracellular matrix in animal cells?

Accepted Answer

Synthesizing hormones

Question 19

A patient has a genetic disorder that prevents the formation of gap junctions in heart muscle. Which symptom would most likely result?

Accepted Answer

Impaired coordination of heart contractions

Question 20

Which of the following best describes how enzyme-linked receptors trigger a phosphorylation cascade?

Accepted Answer

They activate a series of proteins by adding phosphate groups.

Cell–Cell Interactions: Structure, Adhesion, and Communication

Study Guide - Practice Questions