Question 1

Which of the following best describes the main difference between open and closed circulatory systems in animals?

Accepted Answer

Open systems use hemolymph that bathes organs directly, while closed systems confine blood to vessels distinct from interstitial fluid.

Question 2

Which blood vessel type is primarily responsible for the exchange of gases, nutrients, and wastes between blood and tissues?

Accepted Answer

Capillaries

Question 3

A patient with anemia is found to have a point mutation in both genes coding for the β chain of hemoglobin. Which disorder is most likely?

Accepted Answer

Sickle cell anemia (Hb SS)

Question 4

Which plasma protein is most responsible for maintaining osmotic pressure and pH buffering in human blood?

Accepted Answer

Albumin

Question 5

What is the main function of platelets in mammalian blood?

Accepted Answer

Blood clotting

Question 6

During the cardiac cycle, which phase corresponds to ventricular contraction and the highest arterial pressure?

Accepted Answer

Systole

Question 7

Which of the following best explains why blood flow velocity is slowest in capillaries?

Accepted Answer

Capillaries have the largest total cross-sectional area, reducing velocity.

Question 8

A person with blood type AB+ can safely receive blood from which of the following donors?

Accepted Answer

Any blood type

Question 9

Which of the following statements about hemoglobin is correct?

Accepted Answer

Hemoglobin's O2 binding affinity decreases as blood pH decreases (Bohr shift).

Question 10

Which of the following is a direct result of the activation of the sympathetic nervous system on the heart?

Accepted Answer

Increased heart rate

Question 11

A patient is diagnosed with atherosclerosis. Which of the following is most likely to be elevated in their blood?

Accepted Answer

Low-density lipoprotein (LDL)

Question 12

Which of the following best describes the process of blood clot formation?

Accepted Answer

A cascade of reactions converts prothrombin to thrombin, which then converts fibrinogen to fibrin.

Question 13

Which of the following adaptations allows diving mammals to remain underwater for extended periods?

Accepted Answer

Ability to store oxygen in myoglobin within muscles

Question 14

Which of the following is a function of the lymphatic system?

Accepted Answer

Returning excess interstitial fluid to the bloodstream

Question 15

A person with a deficiency in thrombopoietin would most likely have which of the following symptoms?

Accepted Answer

Impaired blood clotting

Question 16

Which of the following best explains why fish gills are highly efficient at extracting oxygen from water?

Accepted Answer

They use a countercurrent exchange system, maintaining a gradient for O2 diffusion.

Question 17

Which of the following would most likely result from a mutation that decreases the number of α-globin chains in hemoglobin?

Accepted Answer

α-Thalassemia

Question 18

Which of the following equations correctly represents the reaction of CO2 transport in red blood cells?

Accepted Answer

$$\mathrm{CO_2$ + H_2O \rightarrow H_2CO_3 \rightarrow H^+ + $$HCO_3$$^-}$$

Question 19

Which of the following best describes the Bohr shift in hemoglobin function?

Accepted Answer

Hemoglobin releases O2 more readily at lower pH.

Question 20

Which of the following is a correct statement about the direction of blood flow in arteries and veins?

Accepted Answer

Arteries carry blood away from the heart, and veins carry blood toward the heart.

LECTURE 19: Circulatory System and Gas Exchange: Structure, Function, and Adaptation

Study Guide - Practice Questions