Question 1

Which of the following best describes the function of the sodium-potassium pump in maintaining the resting membrane potential of a neuron?

Accepted Answer

It moves 3 sodium ions out of the cell and 2 potassium ions into the cell, using ATP, creating a net negative charge inside the cell.

Question 2

A cell is placed in a solution and water moves into the cell, causing it to swell. Which term best describes the solution relative to the cell, and what is the direction of net water movement?

Accepted Answer

The solution is hypotonic; water moves into the cell.

Question 3

Which of the following is a correct sequence of events in cell signaling?

Accepted Answer

Reception $$\rightarrow$$ Transduction $$\rightarrow$$ Response

Question 4

Which of the following best explains why the same signaling molecule can produce different responses in different cell types?

Accepted Answer

Different cells may have different receptors or different intracellular signaling pathways.

Question 5

Which of the following is an example of negative feedback in hormone regulation?

Accepted Answer

Increased blood glucose stimulates insulin release, which lowers blood glucose and reduces further insulin secretion.

Question 6

Which of the following best describes the difference between paracrine, synaptic, and endocrine signaling?

Accepted Answer

Paracrine signals act locally, synaptic signals act across synapses, and endocrine signals travel through the bloodstream to distant targets.

Question 7

A patient is given a drug that blocks voltage-gated sodium channels in neurons. What effect will this have on the generation of action potentials?

Accepted Answer

Action potentials will not be generated because sodium influx is necessary for depolarization.

Question 8

Which of the following best describes facilitated diffusion?

Accepted Answer

Movement of molecules down their concentration gradient through a membrane protein, without energy input.

Question 9

Which of the following is a function of Schwann cells in the nervous system?

Accepted Answer

They form the myelin sheath around axons in the peripheral nervous system.

Question 10

Which of the following best explains the role of G protein-coupled receptors (GPCRs) in cell signaling?

Accepted Answer

They transmit signals from extracellular ligands to intracellular signaling pathways via activation of G proteins.

Question 11

A cell is exposed to a hormone that is lipid-soluble. Which of the following is most likely to occur?

Accepted Answer

The hormone will pass through the plasma membrane and bind to an intracellular receptor.

Question 12

Which of the following best describes the process of osmosis?

Accepted Answer

The movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration.

Question 13

Which of the following is a correct statement about the role of second messengers in cell signaling?

Accepted Answer

Second messengers amplify the signal inside the cell after the receptor is activated.

Question 14

Which of the following best describes the difference between tropic and non-tropic hormones?

Accepted Answer

Tropic hormones stimulate other endocrine glands, while non-tropic hormones act directly on target tissues.

Question 15

A neuron receives multiple excitatory and inhibitory signals at its dendrites. Which process determines whether the neuron will fire an action potential?

Accepted Answer

Summation of all incoming signals at the axon hillock.

Question 16

Which of the following best explains why water-soluble hormones cannot pass through the plasma membrane?

Accepted Answer

They are polar and cannot cross the hydrophobic core of the lipid bilayer.

Question 17

Which of the following is the correct formula for calculating the electrochemical gradient for an ion across a membrane?

Accepted Answer

$$\Delta G = RT \ln \left( \frac{[C]_	ext{in}}{[C]_	ext{out}} ight) + zF\Delta V$$

Question 18

Which of the following best describes the role of astrocytes in the nervous system?

Accepted Answer

They support neurons, help maintain the blood-brain barrier, and regulate the extracellular environment.

Question 19

Which of the following best describes the process of exocytosis?

Accepted Answer

Vesicles fuse with the plasma membrane to release their contents outside the cell.

Question 20

A person is exposed to a loud sound, and their auditory hair cells convert the mechanical stimulus into an electrical signal. This process is best described as:

Accepted Answer

Transduction

General Biology Study Guide: Membranes, Cell Communication, Endocrine System, Nervous System, and Senses

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