Question

What is the cytological basis of law of independent assortment?

• A. There is no blending of alleles
• B. Alleles of a pair separate during gamete formation
• C. Alleles may be dominant or recessive
• D. Pair of chromosomes arrange themselves in line independently in metaphase I

Hint:

Segregation → separation of alleles. Independent assortment → random alignment of homologous chromosomes in meiosis I.

Answer 1

The Correct Option is D

Step 1: Understanding law of independent assortment.
This law states that alleles of different gene pairs assort independently of one another during gamete formation.
Step 2: Cytological explanation.
During metaphase I of meiosis, homologous chromosomes align at the equatorial plate randomly. This independent alignment results in independent assortment of alleles.
Step 3: Analyzing options.
(A) Incorrect — No blending of alleles is true but not the cytological basis.
(B) Incorrect — Separation of alleles explains segregation, not independent assortment.
(C) Incorrect — Dominance/recessiveness is unrelated to independent assortment.
(D) Correct — Random orientation of homologous chromosomes in metaphase I is the true basis.
Step 4: Conclusion.
Thus, the cytological basis of law of independent assortment is independent alignment of chromosomes in metaphase I.