Question 1

Which of the following best describes the difference between osmotic equilibrium and chemical equilibrium in the context of body fluids?

Accepted Answer

Osmotic equilibrium refers to equal water concentration across compartments, while chemical equilibrium refers to equal concentrations of specific solutes across compartments.

Question 2

A patient receives an intravenous (IV) solution that is hypertonic relative to their plasma. What is the most likely effect on their red blood cells?

Accepted Answer

Red blood cells will shrink as water leaves the cells to balance the higher solute concentration outside.

Question 3

Which of the following transport processes requires direct input of cellular energy (ATP) and moves substances against their concentration gradient?

Accepted Answer

Primary active transport

Question 4

The sodium-potassium pump is an example of which type of membrane transport?

Accepted Answer

Primary active transport, moving 3 $$\mathrm{Na^+}$$ out and 2 $$\mathrm{K^+} in $$per ATP hydrolyzed.

Question 5

Which of the following best explains why the resting membrane potential is typically negative in most cells?

Accepted Answer

There is a greater permeability to $$\mathrm{K^+}$$ than $$\mathrm{Na^+}$$ due to leak channels, and $$\mathrm{K^+}$$ diffuses out of the cell, leaving behind negatively charged proteins.

Question 6

A cell is placed in a solution and begins to swell. Which of the following best describes the tonicity of the solution relative to the cell?

Accepted Answer

The solution is hypotonic to the cell.

Question 7

Which of the following is NOT a characteristic of facilitated diffusion?

Accepted Answer

It requires direct input of ATP.

Question 8

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

Accepted Answer

GPCRs activate intracellular signaling cascades by converting ATP to cAMP, which then activates protein kinase A (PKA).

Question 9

A researcher blocks all ATP production in a cell. Which of the following transport processes would be most directly affected?

Accepted Answer

Primary active transport of sodium and potassium

Question 10

Which of the following is an example of paracrine signaling?

Accepted Answer

A cell releasing a signaling molecule that acts on neighboring cells in the same tissue

Question 11

Which of the following best describes the process of exocytosis?

Accepted Answer

Release of substances from the cell when vesicles fuse with the plasma membrane

Question 12

Which of the following is a correct sequence of events in a typical signal transduction pathway involving a second messenger?

Accepted Answer

Ligand binds receptor → G protein activated → ATP converted to cAMP → cAMP activates PKA → PKA phosphorylates target proteins

Question 13

Which of the following best describes the concept of 'upregulation' of a membrane receptor?

Accepted Answer

An increase in the number of receptors on the cell surface in response to low ligand concentration

Question 14

Which of the following is a novel signaling molecule that can act as a paracrine messenger in the nervous system?

Accepted Answer

Nitric oxide ($$\mathrm{NO})$$

Question 15

A cell is exposed to a ligand that binds to a receptor tyrosine kinase. What is the most likely immediate cellular response?

Accepted Answer

Phosphorylation of intracellular proteins by the receptor

Question 16

Which of the following best describes Cannon's postulates regarding homeostatic control systems?

Accepted Answer

The nervous system has a role in preserving the 'fitness' of the internal environment, and some systems are under tonic or antagonistic control.

Question 17

Which of the following is true regarding the movement of substances against their concentration gradient?

Accepted Answer

It requires energy input, often in the form of ATP, and is called active transport.

Question 18

Which of the following is a correct example of secondary active transport?

Accepted Answer

The sodium-glucose cotransporter uses the $$\mathrm{Na^+}$$ gradient established by the sodium-potassium pump to move glucose into the cell.

Question 19

Which of the following best describes the difference between transcellular and paracellular transport in epithelial tissues?

Accepted Answer

Transcellular transport moves substances through the cell, while paracellular transport moves substances between adjacent cells.

Membrane Dynamics and Cellular Communication: Study Guide for Anatomy & Physiology

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