AIIMS 2009 Zoology Mammalian Ova Assertion Reason Question

To evaluate the assertion and reason provided in the question, we need to analyze both statements carefully.

Assertion: Mammalian ova produces hyaluronidase.

Explanation: Hyaluronidase is an enzyme that breaks down hyaluronic acid, which is a component of the extracellular matrix. This enzyme is indeed produced by some reproductive cells, but it is not typically produced by mammalian ova (eggs). In mammals, hyaluronidase is more commonly associated with sperm, particularly in their acrosomes, where it helps facilitate the penetration of the sperm through the zona pellucida (the protective layer surrounding the egg). Therefore, the assertion that mammalian ova produce hyaluronidase is false.

Reason: The eggs of mammals are microlecithal and telolecithal.

Explanation: This statement is incorrect in its classification of mammalian eggs. Mammalian eggs are classified as microlecithal because they contain very little yolk, which is a characteristic of the eggs of most mammals, including humans. However, telolecithal eggs contain a larger amount of yolk that is concentrated toward one end of the egg. Therefore, saying mammalian eggs are telolecithal is also false. In summary, the reason provided does not accurately describe the nature of mammalian eggs.

Conclusion:

Since both the assertion and the reason are false, the correct answer is D) Both Assertion and Reason are false.

Explanation of Other Options:

• A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion: This option is incorrect because both the assertion and reason are false.

• B) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion: This option is incorrect for the same reason – both statements are false.

• C) Assertion is true but Reason is false: This option is incorrect because the assertion is false.

Summary:

• Assertion: False (mammalian ova do not produce hyaluronidase).
• Reason: False (mammalian ova are microlecithal, not telolecithal).

Hence, the answer is D, as both statements are incorrect.