Question

MONOHYBIRD, SEX-LINKED PROBLEMS

In humans, as well as in many other animals, sex is determined by special sex chromosomes. An individual containing two X chromosomes is a female, while an individual possessing an X and Y chromosome is male.

a) In what terms of sex chromosomes, what type of gametes (ova) does a female produce?

b)What are the possible sex chromosomes in a male’s sperm cells?

c) Which parent’s gametes will determine the sex of the offspring?

Answer 1

Female genotype is XX and male genotype is XY. In gamete chromosomes number get halved. Hence, male gamete (sperm) will only contain either X chromosome or Y chromosome. As female is XX, egg will always contain X chromosome.

a) Female will produce gamete the gamete which will have only X chromosome.

b) Male will produce two types of sperm cells one with X chromosome and other with Y chromosome.

c) Male's gamete will determine the sex of offspring. Ova will always contain X-chromosome, if male's sperm with X chromosome combine with ova then offspring will be female and if ova combine with sperm having Y chromosome then offspring will be male.