Question

Use the correct option at the appropriate place. The white blood cells _________ within the immune system identify and destroy foreign bodies _________ such as viruses.

• A. Antigens/Leucocytes
• B. Leucocytes/Antibodies
• C. Antigens/Antibodies
• D. Leucocytes/Antigens

Hint:

Remember: "Anti" (Against) + "Gen" (Generator) = Antigens generate an immune response. Leucocytes are the soldiers (WBCs).

Answer 1

The Correct Option is D

To solve the given sentence completion problem, we need to understand the role of each term related to the immune system.

1. Understanding the Terms:
   • Leucocytes: These are white blood cells that play a crucial role in defending the body against infections and foreign substances.
   • Antigens: These are foreign substances, such as viruses or bacteria, that induce an immune response in the body, particularly the production of antibodies.
2. Sentence Positioning: The sentence asks for which white blood cells within the immune system identify and destroy foreign bodies. Here, Leucocytes fits as the subject (i.e., white blood cells), and they target Antigens (foreign bodies) such as viruses.
3. Correct Matching: The correct choice that fits the blanks in the sentence is Leucocytes/Antigens. This is because leucocytes identify and destroy antigens within the immune system.
4. Eliminating Other Options: The other options do not correctly fit the roles and definitions:
   • Antigens/Leucocytes: Incorrect because antigens do not identify or destroy but rather provide targets for the immune response.
   • Leucocytes/Antibodies: Incorrect because the leucocytes do not destroy antibodies but use them to recognize antigens.
   • Antigens/Antibodies: Incorrect as it misplaces roles within the immune system.

Conclusion: After evaluating the terms and their roles, the correct answer is "Leucocytes / Antigens". Thus, the sentence should read: "The white blood cells Leucocytes within the immune system identify and destroy foreign bodies such as Antigens (viruses)."