Question 1

Which of the following best explains why diffusion is only efficient over small distances in multicellular organisms?

Accepted Answer

Diffusion time is proportional to the square of the distance traveled, so efficiency decreases rapidly as distance increases.

Question 2

Which of the following is a key difference between open and closed circulatory systems?

Accepted Answer

Open circulatory systems have circulatory fluid that bathes organs directly, while closed systems confine blood to vessels.

Question 3

In vertebrates, which blood vessel type is responsible for carrying blood away from the heart?

Accepted Answer

Arteries

Question 4

Which of the following statements about double circulation in mammals is correct?

Accepted Answer

Double circulation allows for higher blood pressure in organs compared to single circulation.

Question 5

A patient is diagnosed with a heart murmur. Which of the following best explains the cause of this condition?

Accepted Answer

Backflow of blood through a defective valve

Question 6

Which equation best describes the relationship between diffusion time ($$t) $$and distance ($$d) $$for small molecules?

Accepted Answer

$$t = d^2$

Question 7

Which of the following is NOT a function of plasma proteins in mammalian blood?

Accepted Answer

Transport of oxygen

Question 8

A person with anemia is likely to have which of the following?

Accepted Answer

Lower than normal hemoglobin levels

Question 9

Which mechanism is used by fish gills to maximize gas exchange efficiency?

Accepted Answer

Countercurrent exchange

Question 10

Which of the following best describes the function of surfactant in the mammalian respiratory system?

Accepted Answer

It coats the surface of alveoli to reduce surface tension and prevent collapse.

Question 11

Which of the following would most likely occur if the lymphatic system failed to return fluid to the bloodstream?

Accepted Answer

Edema, or swelling due to fluid accumulation in tissues

Question 12

Which of the following is a real-world consequence of atherosclerosis?

Accepted Answer

Formation of plaques that can lead to heart attacks or strokes

Question 13

Which of the following best describes the role of the sinoatrial (SA) node in the heart?

Accepted Answer

It sets the rate and timing of cardiac muscle contractions.

Question 14

Which of the following is a correct sequence for the path of blood flow in the mammalian heart?

Accepted Answer

Right ventricle → pulmonary artery → lungs → left atrium → left ventricle → aorta

Question 15

Which of the following is a physiological adaptation that allows animals with long necks, such as giraffes, to maintain adequate blood flow to the brain?

Accepted Answer

Higher systolic pressure to overcome gravity

Question 16

Which of the following is true regarding the regulation of breathing in humans?

Accepted Answer

The medulla oblongata regulates breathing rate in response to changes in pH of cerebrospinal fluid.

Question 17

Which of the following is a multi-step process that occurs during negative pressure breathing in mammals?

Accepted Answer

The diaphragm contracts, increasing lung volume and decreasing air pressure, causing air to flow into the lungs.

Question 18

Which of the following best explains why aquatic animals expend more energy to obtain oxygen compared to terrestrial animals?

Accepted Answer

There is less oxygen available per unit volume in water than in air.

Question 19

Which of the following is a function of platelets in mammalian blood?

Accepted Answer

Blood clotting

Question 20

Which of the following would most likely result from a rupture of a plaque in an artery?

Accepted Answer

Formation of a thrombus, potentially triggering a heart attack or stroke

Circulation and Gas Exchange in Animals: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards