Question

Start with the P generation with the following genotypes (AA x aa). Based on classical Mendelian inheritance, how will a cross between two homozygous parents, one dominant and one recessive, influence future generations? A) The F1 generation will show an even split between the dominant phenotype and the recessive phenotype. B) The F1 generation will all show the dominant trait and future crosses will continue to produce genotypes expressing the dominant trait. C) Although the F1 generation will all show the dominant trait, the offspring will all be heterozygous and increase chances of future variation. D) The F1 generation will show a mix of the dominant phenotype and recessive phenotype and over generations the recessive trait will increase in number.

Answer 1

The answer is C. Although the F1 generation will all show the dominant trait, the offspring will all be heterozygous and increase chances of future variation.

Answer 2

Answer: The correct answer is- C)Although the F1 generation will all show the dominant trait, the offspring will all be heterozygous and increase chances of future variation.

Genotypes of parents are- 'AA' (homozygous dominant) and aa (homozygous recessive).

As we know that dominant trait masks the expression of recessive trait. There can be two possible genotype for dominant that is 'AA' and 'Aa' whereas recessive trait will be produced with single genotype that is 'aa'

Gametes - parent AA will produce 'A' and 'A' whereas 'aa' will produce 'a' and 'a' gamete.

When these parents are crossed, they will produce offspring with 'Aa' (heterozygous dominant trait) in the first generation.

When these offspring become parents, they will increase the chance of variation in the future generation as they can produce offspring with genotype AA (homozygous dominant) , Aa (heterozygous dominant), and aa (homozygous recessive).

Thus, option C) is the right answer.