Question

Study the Pedigree chart given below and answer the questions that follow:

Symbols used in the given Pedigree Chart are as follows:

	Carrier male
	Affected male
	Normal male
	Carrier female
	Affected female
	Normal female

(a) On the basis of the inheritance pattern exhibited in this pedigree chart, what conclusion can you draw about the pattern of inheritance?

(b) If the female is homozygous for the affected trait in this pedigree chart, then what percentage of her sons will be affected?

(c) Give the genotype of offspring 1, 2, 3 and 4 in III generations.

OR

(c) In this type of inheritance pattern, out of male and female children which one has less probability of receiving the trait from the parents? Give a reason.

Answer 1

(a) X-linked, Recessive trait

(b) 100%

(c)

• XY or XY,
• X X,
• XY,
• XX 

OR

The possibility of the female getting the trait is less.

The female will get the trait only if the mother is at least a carrier and the father is affected.