Question 1

Which of the following best describes the main function of cell signaling in the context of an impala's flight response to a predator?

Accepted Answer

It coordinates rapid communication between cells to alter metabolism and enable quick muscle responses.

Question 2

Which type of cell signaling involves the direct transfer of signaling molecules through cell junctions between adjacent cells?

Accepted Answer

Direct intercellular signaling

Question 3

A researcher observes that a group of bacteria only begin to produce a biofilm when their population density is high. Which signaling mechanism is most likely responsible for this behavior?

Accepted Answer

Quorum sensing

Question 4

Which of the following is NOT a typical outcome of cell signaling pathways?

Accepted Answer

Direct synthesis of ATP from glucose without enzymes

Question 5

Which of the following best explains why signal transduction pathways often involve multiple steps and second messengers such as cAMP?

Accepted Answer

To amplify the signal and allow for regulation and specificity in the response.

Question 6

A mutation causes a receptor tyrosine kinase (RTK) to be 'always on.' What is a likely consequence of this mutation in a cell?

Accepted Answer

The cell may undergo uncontrolled growth and division, potentially leading to cancer.

Question 7

Which of the following hormones is most likely to use an intracellular receptor rather than a cell-surface receptor?

Accepted Answer

Cortisol

Question 8

In the context of cholera infection, which step in the signaling pathway is disrupted, leading to excessive water loss from intestinal cells?

Accepted Answer

The G protein is locked in its active form, causing continuous production of cAMP.

Question 9

Which of the following best describes the role of a ligand in cell signaling?

Accepted Answer

A ligand is a molecule that binds noncovalently to a receptor, causing a conformational change that activates the receptor.

Question 10

Which of the following is the correct sequence of events in G-protein coupled receptor (GPCR) signaling?

Accepted Answer

Signal molecule binds to receptor → GPCR changes shape → GPCR activates G-protein → G-protein activates target protein

Question 11

A cell is exposed to both epinephrine and a growth factor at the same time. Which statement best explains how the cell can produce different responses to these signals?

Accepted Answer

Each signal binds to a specific receptor and activates distinct signal transduction pathways, leading to different cellular responses.

Question 12

Which of the following best illustrates the concept of contact-dependent signaling?

Accepted Answer

A T-cell interacts with a B-cell via membrane proteins to help the B-cell produce antibodies.

Question 13

Which equation best represents the amplification of a signal in a phosphorylation cascade?

Accepted Answer

$$10^1$$ \rightarrow $$10^2$$ \rightarrow $$10^3$$ \rightarrow $$10^4$$

Question 14

Which of the following is a reason why not all cells respond to every hormone or signal molecule in the body?

Accepted Answer

Only cells with the appropriate receptor for a specific signal can respond to that signal.

Question 15

Which of the following best explains why signal transduction pathways are often compartmentalized within the cell?

Accepted Answer

To prevent cross-talk between different signaling pathways and ensure specificity of response.

Question 16

A pharmaceutical company is developing a drug that inhibits tyrosine kinase activity. Which disease is this drug most likely intended to treat?

Accepted Answer

Certain types of cancer

Question 17

Which of the following is a correct statement about second messengers such as cAMP?

Accepted Answer

They are small molecules that relay signals from receptors on the cell surface to target molecules inside the cell.

Question 18

Which of the following best describes the role of phosphorylation cascades in signal transduction?

Accepted Answer

They amplify the signal by activating multiple downstream proteins through sequential phosphorylation.

Question 19

A patient is exposed to a toxin that prevents the release of ligands from cells. Which step in the cell signaling process will be directly affected?

Accepted Answer

Ligand binding to receptor

Cell Signaling and Communication: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard