Question 1

Which of the following best describes the process of apoptosis as depicted in the cell signaling pathway diagram?

Accepted Answer

A cell undergoes programmed cell death in the absence of survival signals.

Question 2

In the context of bacterial communication, what is the primary function of quorum sensing?

Accepted Answer

To coordinate group behaviors such as spore formation based on population density.

Question 3

Which of the following is a key difference between gap junctions in animal cells and plasmodesmata in plant cells?

Accepted Answer

Both allow for direct cytoplasmic exchange, but gap junctions are in animal cells and plasmodesmata are in plant cells.

Question 4

Which type of signaling involves the release of neurotransmitters across a synapse to a target cell?

Accepted Answer

Synaptic signaling

Question 5

A hormone is released into the bloodstream and acts on distant target cells. Which type of signaling is this?

Accepted Answer

Endocrine signaling

Question 6

Which of the following is the correct sequence of the three stages of cell signaling?

Accepted Answer

Signal reception → Signal transduction → Cellular response

Question 7

What is the primary role of GTP in the G protein-coupled receptor (GPCR) pathway?

Accepted Answer

GTP activates the G protein, allowing it to relay the signal to downstream enzymes.

Question 8

Which of the following events occurs after ligand binding to a receptor tyrosine kinase (RTK)?

Accepted Answer

The receptor undergoes dimerization and cross-phosphorylation of tyrosine residues.

Question 9

Which property must a signaling molecule have to activate an intracellular receptor?

Accepted Answer

It must be small and hydrophobic to diffuse through the plasma membrane.

Question 10

In the fight-or-flight response of an impala, which molecule acts as the signaling molecule to initiate the breakdown of glycogen?

Accepted Answer

Epinephrine

Question 11

Which of the following best explains why gap junctions can be both beneficial and detrimental to animal cells?

Accepted Answer

They allow for rapid communication but can also facilitate the spread of toxins or pathogens.

Question 12

Which of the following is a direct result of ligand binding to a ligand-gated ion channel receptor?

Accepted Answer

The receptor opens to allow ions to flow down their concentration gradient.

Question 13

Which of the following scenarios best illustrates paracrine signaling?

Accepted Answer

A cell releases growth factors that diffuse to nearby cells to stimulate proliferation.

Question 14

What is the main function of relay molecules in the signal transduction stage of cell signaling?

Accepted Answer

To amplify and transmit the signal from the receptor to the cellular response machinery.

Question 15

Which of the following is a possible outcome if a cell fails to receive any extracellular signals?

Accepted Answer

The cell will initiate apoptosis, or programmed cell death.

Question 16

Which of the following best describes the specificity of yeast cell mating factors?

Accepted Answer

Each mating factor binds only to the receptor of the opposite mating type.

Question 17

Which of the following is true regarding the activation of a G protein in the GPCR pathway?

Accepted Answer

The G protein is activated when GDP is exchanged for GTP on the alpha subunit.

Question 18

Which of the following is a potential consequence of abnormal receptor tyrosine kinase (RTK) activity?

Accepted Answer

Uncontrolled cell proliferation, which can lead to cancer.

Question 19

Which of the following best explains why intracellular receptors often mediate slower cellular responses compared to cell surface receptors?

Accepted Answer

Intracellular receptors often alter gene expression, which involves transcription and translation.

Question 20

Which of the following best describes the role of phosphorylation in receptor tyrosine kinase (RTK) activation?

Accepted Answer

Phosphorylation of tyrosine residues on the RTK dimer fully activates the receptor and allows for multiple downstream responses.

BIO 102 Chapter 11 Modules 1-2

Study Guide - Practice Questions