Question

Given below are two statements, one is labelled as Assertion (A) and other labelled as Reason (R).
Assertion (A): Genetic recombination can result in the separation of linked genes.
Reason (R): Genetic recombination can break the linkage between two genes that are located close together on a chromosome.
In light of the above statements, choose the correct answer from the options given below:

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

The frequency of recombination is proportional to the distance between genes. Tightly linked genes (located very close together) rarely undergo recombination and are almost always inherited together.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Linked genes are genes located on the same chromosome.
During meiosis, physical crossing over (homologous recombination) can occur between homologous chromosomes, which can separate these linked alleles and generate recombinant gametes.

Step 2: Detailed Explanation:
Let us evaluate both statements:
- Assertion (A) is true: Although linked genes tend to be inherited together because they are on the same chromosome, crossing over during Prophase I of meiosis can exchange segments between non-sister chromatids.
This process can separate linked genes, creating new combinations of alleles in the offspring.
- Reason (R) is false: The probability of a crossing over event occurring between two linked genes is directly proportional to the physical distance between them.
If two genes are located very close together on the chromosome, the likelihood of a crossover event occurring in the tiny space between them is extremely low (approaching zero).
These genes are tightly linked and are rarely separated by recombination.
Therefore, genetic recombination cannot easily break the linkage between genes that are located close together.
Thus, Assertion (A) is true, but Reason (R) is false.

Step 3: Final Answer:
Hence, the correct option is (C).