Q: Which equation correctly calculates the osmolarity of a solution containing 0.2 M MgCl$$_2$$ and 0.1 M glucose?

$$0.2 \times 3 + 0.1 \times 1 = 0.7$$ Osm/L

Q: A solution contains 0.1 M NaCl and 0.1 M MgCl$$_2. $$What is the total osmolarity of the solution?

$$0.1 \times 2 + 0.1 \times 3 = 0.5$$ Osm/L

Question 1

Which of the following best describes the main difference between osmolarity and tonicity?

Accepted Answer

Osmolarity refers to the number of particles in solution, while tonicity describes the effect of a solution on cell volume.

Question 2

A red blood cell is placed in a solution containing 0.3 M NaCl and 0.3 M urea. Which statement best predicts the cell's response?

Accepted Answer

The cell will shrink because NaCl is non-penetrating and urea is penetrating, but only NaCl contributes to tonicity, making the solution hypertonic.

Question 3

Which equation correctly calculates the osmolarity of a solution containing 0.2 M MgCl$$_2$$ and 0.1 M glucose?

Accepted Answer

$$0.2 	imes 3 + 0.1 	imes 1 = 0.7$$ Osm/L

Question 4

A patient with severe hypoalbuminemia develops ascites. Which mechanism best explains the accumulation of fluid in the abdominal cavity?

Accepted Answer

Decreased plasma oncotic pressure fails to retain water in the blood vessels, allowing fluid to leak into the interstitial and peritoneal spaces.

Question 5

Which of the following best describes the movement of water during osmosis?

Accepted Answer

Water moves from an area of lower solute concentration to an area of higher solute concentration.

Question 6

A cell is placed in a solution and swells until it bursts. Which type of solution was the cell placed in?

Accepted Answer

Hypotonic solution

Question 7

Which of the following is true regarding the distribution of body water?

Accepted Answer

About two-thirds of total body water is found in the intracellular fluid compartment.

Question 8

A selectively permeable membrane separates two compartments: A contains pure water, B contains 1 M glucose. What is the direction of water movement and what is the osmotic pressure required to stop it?

Accepted Answer

Water moves from A to B; the osmotic pressure equals the pressure needed to prevent water from moving into B.

Question 9

Which of the following best explains why people with cystic fibrosis have thick, sticky mucus in their airways?

Accepted Answer

Impaired secretion of NaCl into the airway lumen reduces the osmotic gradient, so less water enters the mucus, making it thick.

Question 10

Which of the following is a correct statement about the chemical equilibrium of body fluid compartments?

Accepted Answer

The ECF and ICF are in osmotic equilibrium but chemical disequilibrium.

Question 11

A solution contains 0.1 M NaCl and 0.1 M MgCl$$_2. $$What is the total osmolarity of the solution?

Accepted Answer

$$0.1 	imes 2 + 0.1 	imes 3 = 0.5$$ Osm/L

Question 12

Which of the following best describes the role of albumin in maintaining plasma volume?

Accepted Answer

Albumin creates an oncotic pressure that helps retain water in the blood vessels.

Question 13

Which transport process requires energy in the form of ATP to move substances against their concentration gradient?

Accepted Answer

Protein-mediated active transport

Question 14

A patient is given an intravenous solution that is hypertonic to their plasma. What is the most likely effect on their red blood cells?

Accepted Answer

The cells will shrink as water leaves the cells to balance the osmotic gradient.

Question 15

Which of the following best explains why water content as a percentage of body weight decreases with age?

Accepted Answer

Older individuals have more adipose tissue, which contains less water than lean tissue.

Question 16

Which of the following is an example of vesicular transport?

Accepted Answer

Endocytosis of cholesterol by liver cells

Question 17

A cell is placed in a 0.9% NaCl solution. What is the tonicity of this solution relative to the cell, and what will happen to the cell?

Accepted Answer

Isotonic; the cell will remain the same size.

Question 18

Which of the following best describes the function of the cell membrane in relation to body fluid compartments?

Accepted Answer

It acts as a selectively permeable barrier between the intracellular and extracellular fluid compartments.

Question 19

Which of the following scenarios best illustrates the principle of diffusion?

Accepted Answer

Oxygen moving from the alveoli into the blood due to a concentration gradient.

Body Fluid Compartments, Osmosis, and Membrane Transport in Anatomy & Physiology

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