Question 1

Which of the following best distinguishes blood in a closed circulatory system from hemolymph in an open circulatory system?

Accepted Answer

Blood is confined to vessels and specialized for transport, while hemolymph bathes organs directly and is not confined.

Question 2

A centrifuged vial of human blood separates into layers. Which component is found at the bottom and what is its primary function?

Accepted Answer

Erythrocytes; transport of $$O_2$$ and $$CO_2$$

Question 3

Which of the following best explains why mature erythrocytes lack mitochondria?

Accepted Answer

To prevent consumption of the oxygen they transport, allowing them to rely on anaerobic fermentation for ATP production.

Question 4

Which of the following is a granulocyte that increases in number during bacterial infections and is the most abundant leukocyte?

Accepted Answer

Neutrophil

Question 5

A patient with sickle cell disease is experiencing severe pain and fatigue. Which of the following best explains the underlying cause?

Accepted Answer

Abnormal hemoglobin polymerizes under low oxygen, causing erythrocytes to sickle, block vessels, and reduce oxygen delivery.

Question 6

Which plasma protein is primarily responsible for maintaining osmotic balance in blood?

Accepted Answer

Albumin

Question 7

What is the primary function of platelets in the process of hemostasis?

Accepted Answer

They aggregate to form a temporary plug at the site of vessel injury.

Question 8

Which of the following best describes the role of thrombin in blood clotting?

Accepted Answer

Thrombin catalyzes the conversion of fibrinogen to fibrin, forming an insoluble clot.

Question 9

A person with a low hematocrit is likely to experience which of the following symptoms, and why?

Accepted Answer

Fatigue, due to reduced oxygen-carrying capacity of the blood.

Question 10

Which of the following statements about hematopoietic stem cells (HSCs) is correct?

Accepted Answer

HSCs are multipotent cells in bone marrow that give rise to all formed elements of blood.

Question 11

Which of the following best describes the difference between LDL and HDL in cholesterol transport?

Accepted Answer

LDL delivers cholesterol to tissues, while HDL removes excess cholesterol from tissues to the liver.

Question 12

A patient undergoes balloon angioplasty to treat a blocked artery. What is the main limitation of this procedure, and how is it addressed?

Accepted Answer

Restenosis (re-narrowing) can occur, which is addressed by placing a stent to keep the artery open.

Question 13

Which of the following is a direct consequence of atherosclerosis in a coronary artery?

Accepted Answer

Reduced blood flow to heart muscle, potentially causing myocardial infarction.

Question 14

Which of the following best explains why hypertension is called the 'silent killer'?

Accepted Answer

It often has no symptoms until it causes serious complications like heart attack or stroke.

Question 15

Which of the following is a positive feedback mechanism in the process of hemostasis?

Accepted Answer

Platelet aggregation induces the release of chemicals that attract more platelets to the site of injury.

Question 16

A person with a genetic mutation causing defective LDL receptors is at increased risk for which condition, and why?

Accepted Answer

Atherosclerosis, because LDL accumulates in the blood and deposits in vessel walls.

Question 17

Which of the following best describes the process of a stroke caused by an embolus?

Accepted Answer

A blood clot breaks off, travels through the bloodstream, and lodges in a cerebral artery, blocking blood flow to brain tissue.

Question 18

Which of the following is a real-world example of pleiotropy as discussed in the context of sickle cell disease?

Accepted Answer

A single gene mutation causes both sickled erythrocytes and resistance to malaria.

BIO 102 Chapter 42 Part 1 C

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