Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Forelimbs of human and bats are homologous.
Reason R: Forelimbs of humans and bats have similar anatomical structure.
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. A is false but R is true
• B. Both A and R are correct and R is the correct explanation of A
• C. Both A and R are true, but R is not the correct explanation of A
• D. A is true but R is false

Hint:

Homology \(\rightarrow\) Similar anatomy, different functions \(\rightarrow\) Divergent evolution. Analogy \(\rightarrow\) Different anatomy, similar functions \(\rightarrow\) Convergent evolution (e.g., wings of butterfly and bird).

Answer 1

The Correct Option is B

Step 1: Read both statements.
Assertion A: forelimbs of humans and bats are homologous. Reason R: their forelimbs have a similar anatomical structure.
Step 2: Recall homology.
Homologous structures come from a common ancestor and share the same basic bone plan, even if they do different jobs. They are evidence of divergent evolution.
Step 3: Test Assertion A.
Humans and bats are both mammals from a common ancestor, and both forelimbs share humerus, radius, ulna, carpals, metacarpals, and phalanges. So A is true.
Step 4: Test Reason R.
The same bone arrangement means they do share a similar anatomical structure. So R is true.
Step 5: Link A and R.
Homology is defined by exactly this shared underlying structure, so the similar anatomy is the very reason we call them homologous. R correctly explains A.
Step 6: Choose the option.
Both A and R are correct and R is the correct explanation of A, which is option (2).
\[ \boxed{\text{Both A and R correct, R explains A}} \]