How do leukocytes and erythrocytes differ in terms of their cellular structure and function in humans?

• A. Both leukocytes and erythrocytes lack nuclei and are involved in oxygen transport.
• B. Leukocytes contain nuclei and are involved in immune responses, while erythrocytes lack nuclei and primarily transport oxygen.
• C. Erythrocytes contain nuclei and are involved in immune responses, while leukocytes lack nuclei and transport oxygen.
• D. Leukocytes and erythrocytes both contain nuclei and have identical functions.

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the basic definitions of leukocytes and erythrocytes. Leukocytes, also known as white blood cells, are part of the immune system and help defend the body against infections and foreign invaders. Erythrocytes, also known as red blood cells, are primarily responsible for transporting oxygen to tissues and removing carbon dioxide.
2. Step 2: Examine the structural differences between leukocytes and erythrocytes. Leukocytes contain nuclei, which allow them to perform complex functions such as producing antibodies and signaling other immune cells. Erythrocytes, on the other hand, lack nuclei and most organelles, which maximizes space for hemoglobin, the protein responsible for oxygen transport.
3. Step 3: Analyze the functional differences. Leukocytes are involved in immune responses, such as attacking pathogens, producing antibodies, and regulating inflammation. Erythrocytes are specialized for oxygen transport due to their high hemoglobin content and biconcave shape, which increases surface area for gas exchange.
4. Step 4: Address the incorrect statements in the problem. The claim that both leukocytes and erythrocytes lack nuclei and are involved in oxygen transport is false because leukocytes contain nuclei and are not involved in oxygen transport. Similarly, the statement that erythrocytes contain nuclei and are involved in immune responses is incorrect because erythrocytes lack nuclei and are not part of the immune system.
5. Step 5: Conclude by summarizing the correct answer: Leukocytes contain nuclei and are involved in immune responses, while erythrocytes lack nuclei and primarily transport oxygen. This distinction highlights their specialized roles in the human body.