Blood：练习题

Which component of blood is responsible for transporting oxygen?

Which type of white blood cell is primarily responsible for producing antibodies?

During a bacterial infection, the body mobilises its immune defenses. Which sequence correctly describes the roles of specific white blood cells in eliminating a bacterial pathogen?

A person sustains a deep cut, initiating a series of events leading to blood clot formation. This process is vital to prevent excessive blood loss and pathogen entry.

Which statement correctly outlines the sequence of events and key molecules involved in converting liquid blood into a solid clot?

The diagram shows a sample of human blood that has been mixed with an anticoagulant and then centrifuged. The components have separated into three distinct layers based on density: a straw-coloured liquid (X), a thin white layer (Y), and a red layer (Z).

Which statement correctly identifies the contents or functions of these layers?

State the importance of platelets in the blood and describe one potential consequence if a person has a very low platelet count.

Identify the blood cell in a photomicrograph that is characterized by a lobed nucleus and describe how its cytoplasm appears compared to a red blood cell.

Contrast the defense mechanisms of lymphocytes and phagocytes, specifically explaining how the shape-specific nature of antibodies differs from the process of engulfing pathogens.

(a) List the four main components of human blood.

(b) Describe the specific functions of red blood cells, lymphocytes, and phagocytes in maintaining human health.

(c) Explain the importance of blood clotting in preventing blood loss and the entry of pathogens after an injury.

A medical researcher analyzed the blood composition of two subjects. Subject A lives at sea level, and Subject B recently moved to a high-altitude mountain range. The data for their red blood cell (RBC) count is provided below:

Subject A: \( 5.0 \times 10^{12} \) cells per \( dm^3 \)
Subject B: \( 6.5 \times 10^{12} \) cells per \( dm^3 \)

(a) Calculate the percentage increase in the RBC count for Subject B compared to Subject A. Use this calculation to explain how this change serves as an adaptation to the reduced oxygen concentration in the atmosphere. (3 points)

(b) While red blood cells transport gases, the plasma is responsible for transporting a variety of other substances. Identify two specific waste products transported in the plasma and describe the role of the plasma in the transport of hormones from their site of production. (2 points)

(c) The process of blood clotting is essential for survival. Describe the chemical conversion of fibrinogen to fibrin and explain the mechanical role of the resulting fibers in preventing excessive blood loss. (3 points)