Question

Mendel’s last law is

• A. Dominance
• B. Segregation
• C. Polygenic inheritance
• D. Independent assortment

Answer 1

The correct option is D

Independent assortment

The correct option is D.

Explanation for the correct option:

Option D:

1. Independent assortment is the last law of Mendel.
2. The Law of independent assortment is based on the dihybrid cross.
3. It states that the inheritance of one character is always independent of the inheritance of other characters within the same individual.
4. In other words, if the inheritance of more than one character is studied simultaneously, the factors or genes for each character assort out independently of the other gene or factor.
5. A good example of independent assortment is the Mendelian dihybrid cross.
6. The presence of new combinations - round green and wrinkled yellow, suggests that the genes for the shape of the seed and color of the seed are assorted independently.

Explanation for the incorrect options:

Option A:

1. The law of dominance is the first law of Mendel.
2. It states that hybrid offspring will only inherit the dominant trait in the phenotype.
3. For example: when pea plants with round seeds (RR) are crossed with plants with wrinkled seeds (rr), all seeds in F1 generation were found to be round (Rr).

Option B:

1. It is the second law of Mendel.
2. It states that when an organism makes gametes, each gamete receives just one gene copy, which is selected randomly.
3. For example, the gene for seed color in pea plants exists in two forms. There is one form or allele for yellow seed color (Y) and another for green seed color (y).

Option D:

1. Polygenic inheritance refers to the inheritance of a trait governed by more than one gene.
2. Example: human skin and eye color, height, weight, and intelligence in people; and kernel color of wheat.

Final answer: Mendel’s last law is Independent assortment.