Question

1. A child will be a girl if *

it receives an X chromosome and a Y chromosome from its mother

it receives a Y chromosome from its mother

it receives an X chromosome from its father

it receives a Y chromosome from its father

2.When black rabbits mate with white rabbits, all of the offspring come out gray. This is an example of *

incomplete dominance

a sex linked disorder

an autosomal (chromosomes 1-22) recessive disorder

simple dominance

3.Mendel concluded that gametes or sex cells have only one allele for each genetic trait. This conclusion is supported by the observation that *

haploid cells are produced by mitosis

diploid cells are produced by meiosis

diploid cells are produced by mitosis

haploid cells are produced by meiosis

4.

Colorblindness (n) is a sex-linked recessive trait, normal color-vision (N) is dominant (but still sex-linked!). A colorblind woman (XnXn) has children with a man who is not colorblind (XNY). Which could be true about the offspring? Choose all that apply. *

All of her daughters would be carriers.

All of her sons will be colorblind.

All of her daughters will be colorblind.

All of her sons will be carriers.

Answer 1

Ans . (1) it receives an X chromosome from its father

Ans .(2) incomplete dominance

Ans .(3) haploid cells are produced by meiosis

Ans .(4) The following statements are correct:-

• All of her daughter would be carriers.
• All of her sons will be colourblind.

Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely expressed over its paired allele. This results in a third phenotype in which the expressed physical trait is a combination of phenotypes of both alleles.