Question 1

Which of the following best describes quorum sensing in bacteria?

Accepted Answer

A mechanism where bacteria count their population density using chemical signals and collectively change behavior when a threshold is reached.

Question 2

A hormone is released from the adrenal gland and travels through the bloodstream to affect the liver. What type of signaling is this?

Accepted Answer

Endocrine signaling

Question 3

Which of the following is TRUE about fat-soluble hormones?

Accepted Answer

They diffuse through the plasma membrane and bind to intracellular receptors.

Question 4

A patient with pituitary dwarfism most likely has a deficiency in which hormone?

Accepted Answer

Human Growth Hormone (HGH)

Question 5

Which brain region is primarily responsible for regulating automatic survival functions such as heart rate and breathing?

Accepted Answer

Medulla

Question 6

The famous case of Phineas Gage provided evidence for which of the following?

Accepted Answer

The frontal lobe is involved in personality and decision making.

Question 7

During the rising (depolarization) phase of an action potential, what is happening?

Accepted Answer

Na+ channels open and Na+ floods into the cell, making the inside positive

Question 8

Which of the following best describes a synapse?

Accepted Answer

The space between two neurons where neurotransmitters carry the signal from one cell to the next

Question 9

Which area of the body would you expect to have the highest density of touch-sensitive nerves?

Accepted Answer

Lips

Question 10

What are the three main stages of cell signaling, in order?

Accepted Answer

Reception, transduction, response

Question 11

How does a ligand-gated ion channel receptor work?

Accepted Answer

A ligand binds and the channel opens, allowing ions to flow down their concentration gradient into the cell

Question 12

In G-protein-linked receptor signaling, what activates the G-protein?

Accepted Answer

GTP replaces GDP on the G-protein after the receptor is activated by ligand binding

Question 13

Receptor tyrosine kinases (RTKs) are activated through which process?

Accepted Answer

Dimerization: a signal molecule binds two receptor monomers, pulling them together to activate the catalytic domain

Question 14

Which of the following is a correct sequence for the action of a steroid hormone?

Accepted Answer

Steroid hormone diffuses into the cell, binds to an intracellular receptor, and the complex activates gene transcription

Question 15

In the epinephrine signaling pathway, what role does cAMP play?

Accepted Answer

It acts as a second messenger that relays and amplifies the signal after the receptor is activated

Question 16

Which of the following best describes signal amplification in cell signaling?

Accepted Answer

A single ligand molecule can activate multiple downstream molecules, resulting in a large cellular response

Question 17

Caffeine keeps you awake by interfering with which aspect of cell signaling?

Accepted Answer

It blocks the A2A receptor, preventing the tiredness signaling cascade from starting

Question 18

Apoptosis is best described as:

Accepted Answer

A programmed form of cell death, integrated by signaling pathways, that avoids triggering an inflammatory response

Question 19

Which of the following is a real-life example of paracrine signaling?

Accepted Answer

A neuron releasing neurotransmitters that affect a neighboring muscle cell

Question 20

Which of the following best explains why the Na+/K+ pump is essential after an action potential?

Accepted Answer

It actively transports 3 Na+ out and 2 K+ in, using ATP, to restore the original ion balance

Cell Communication: Mechanisms and Pathways in Biology

스터디 가이드 - 연습 문제