Question

Lack of independent assortment of two genes A and B in fruit fly Drosophila is due to

• A. Recombination
• B. Repulsion
• C. Crossing over
• D. Linkage

Answer 1

The correct option is D

Linkage

The correct option is D.

Explanation of the correct option:

Option D:

1. Mendel's law of independent assortment states that the segregation of one trait is independent of the other.
2. At the time of gamete formation, two factors or alleles of different genes assort independently.
3. Morgan demonstrated that when genes are found on the same chromosome, they exhibit physical association or linkage, which explains why they are frequently inherited together, and there are more parental combinations.
4. Linkage is referred to the phenomenon wherein alleles located close together on a chromosome show tendency to be inherited together during meiosis

Explanation of the incorrect options:

Option A:

Recombination is the process by which pieces of DNA are broken and recombined to create new allele combinations.

Option B:

Repulsion is the tendency of genes presents on different chromosomes to stay separate.
Option C:

Chromosomal crossover, also known as crossing over, is the exchange of genetic material between two homologous chromosomes' non-sister chromatids during sexual reproduction.
Final answer:
In genetics and genomics, linkage refers to the proximity of genes or other DNA sequences on the same chromosome.