Question 1

Which of the following best describes paracrine signaling?

Accepted Answer

A signal molecule is released by a cell and affects nearby target cells in the local environment.

Question 2

Which of the following is NOT a stage of cell signaling as described by Earl Sutherland?

Accepted Answer

Amplification

Question 3

What is the primary function of G protein-coupled receptors (GPCRs) in cell signaling?

Accepted Answer

To transmit signals from extracellular ligands to intracellular G proteins, initiating a signaling cascade

Question 4

Which of the following best explains why only certain cells respond to a particular hormone?

Accepted Answer

Only cells with the appropriate receptor for the hormone can respond.

Question 5

Which of the following is a correct sequence of events for G protein activation?

Accepted Answer

A signaling molecule binds to the GPCR, causing GDP to be replaced by GTP on the G protein, activating it.

Question 6

Which type of cell signaling involves hormones traveling through the bloodstream to reach distant target cells?

Accepted Answer

Endocrine signaling

Question 7

What is the main role of second messengers such as cyclic AMP ($$cAMP) in $$signal transduction pathways?

Accepted Answer

They relay and amplify signals from receptors to target molecules inside the cell.

Question 8

Which of the following best describes the function of ligand-gated ion channels?

Accepted Answer

They open or close in response to ligand binding, allowing specific ions to cross the membrane.

Question 9

A mutation prevents a cell from producing functional receptor tyrosine kinases (RTKs). Which process would be most directly affected?

Accepted Answer

Phosphorylation of target proteins in response to growth factors

Question 10

Which of the following is a key feature of a phosphorylation cascade in cell signaling?

Accepted Answer

It amplifies the signal by activating multiple proteins at each step.

Question 11

Which of the following best describes the role of apoptosis in multicellular organisms?

Accepted Answer

It removes damaged or unnecessary cells, contributing to normal development and tissue maintenance.

Question 12

Which of the following is true about intracellular receptors?

Accepted Answer

They are found inside the cell and bind hydrophobic signaling molecules.

Question 13

Which of the following is an example of synaptic signaling?

Accepted Answer

A neuron releases neurotransmitters that cross a synapse to stimulate a muscle cell.

Question 14

Which of the following best explains why a phosphorylation cascade can amplify a cell signal?

Accepted Answer

Each activated kinase can activate many downstream kinases, resulting in a large number of activated proteins.

Question 15

Which of the following is a correct statement about the difference between cAMP and AMP?

Accepted Answer

cAMP is a second messenger with a cyclic structure, while AMP is a nucleotide with a linear structure.

Question 16

Which of the following is an example of a cellular response to a signal transduction pathway?

Accepted Answer

Opening of ion channels in response to neurotransmitter binding

Question 17

Which of the following best describes the role of transcription factors in cell signaling?

Accepted Answer

They regulate gene expression in response to signaling pathways.

Question 18

Which of the following is a real-life example of apoptosis?

Accepted Answer

Formation of spaces between developing fingers and toes in a human embryo

Question 19

Which of the following is a function of gap junctions in animal cells?

Accepted Answer

They allow direct communication between adjacent cells by permitting the passage of ions and small molecules.

Cell Signaling and Communication: Study Notes (Chapter 5)

Study Guide - Practice Questions