Question

Given below are two statements:
Statement I : Linked genes are present on the same chromosome
Statement II : The genes present on the same chromosome cannot show independent assortment if they are not present wide apart
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is correct but Statement II is false
• D. Statement I is incorrect but Statement II is true

Hint:

Linked genes reside on the same chromosome; syntenic genes assort independently only when separated by $\ge 50\,\text{cM}$ (50% recombination).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Genes located on the same physical chromosome are syntenic and tend to be inherited together as a linkage group.

Step 2: Detailed Explanation:
1. Statement I is TRUE: Linked genes are located syntenically along the linear DNA axis of the same physical chromosome.
2. Statement II is TRUE: Linked genes that are situated close to each other ($< 50\,\text{cM}$) undergo crossing-over with a frequency of less than $50\%$, producing more parental than recombinant gametes, and thus violate Mendel's Law of Independent Assortment unless separated by a map distance $\ge 50\,\text{cM}$.

Step 3: Final Answer:
Hence, both Statement I and Statement II are true.