NEETZoologyPrinciples of Inheritance and Variation
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Grasshoppers exhibit male heterogamety. Reason (R): Male grasshoppers produce two types of gametes, one bearing an X chromosome and the other bearing a Y chromosome. In the light of the above statements, choose the most appropriate answer from the options given below.
Options
- A(A) is true but (R) is false.
- BBoth (A) and (R) are true and (R) is the correct explanation of (A).
- CBoth (A) and (R) are true but (R) is not the correct explanation of (A).
- D(A) is false but (R) is true.
Correct answer
A. (A) is true but (R) is false.
Step-by-step solution
Assertion (A) is true because grasshoppers show the XX-XO type of sex determination, where males produce two different types of gametes (sperms), which is the definition of male heterogamety. Reason (R) is false because in the XX-XO mechanism, males do not possess a Y chromosome. Instead, they produce two types of sperms: 50% bear an X chromosome and the other 50% do not contain any sex chromosome (often denoted as 'O'). Answer: (A) is true but (R) is false.