The grandsons of a colour blind male having the following probability of being colour blind is:
a) 0%
b) 50%
c) 25%
d) 12.5%
The book says that the correct answer is b) 50% but I really don't think so
Please explain how
Dear Student,
Color blindness is genetic disease in which differentiation ability between some colors is decreased. It is a X-linked recessive disorder, which means generally males will be affected if any one of parents is effected while females mostly act as carrier (as they have 2 X chromosomes so one will compensates/masks the effect of other). Denoted by Xc_.
Now, according to this question, Grandfather is color blind (XcY). Being a recessive disorder it may skip generation. In other words, the (His) children may or may not contain the trait. Therefore, it is difficult to predict the exact probability of effected grandsons (only depends on the genotypes of their parents, that is the children of grandfather). But as there is a chance that the trait gets inherited, therefore, the answer is 50%.
For example
Grandparents GFX'Y X GM?
Parents F* X M?
Children S*1 or S2* or G?
X'Y - Affected grandfather, ? - unknown genotype, * - May or may not get the trait (50% chances being a recessive trait)
Hope this information will clear your doubts about the topic.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
Regards
Color blindness is genetic disease in which differentiation ability between some colors is decreased. It is a X-linked recessive disorder, which means generally males will be affected if any one of parents is effected while females mostly act as carrier (as they have 2 X chromosomes so one will compensates/masks the effect of other). Denoted by Xc_.
Now, according to this question, Grandfather is color blind (XcY). Being a recessive disorder it may skip generation. In other words, the (His) children may or may not contain the trait. Therefore, it is difficult to predict the exact probability of effected grandsons (only depends on the genotypes of their parents, that is the children of grandfather). But as there is a chance that the trait gets inherited, therefore, the answer is 50%.
For example
Grandparents GFX'Y X GM?
Parents F* X M?
Children S*1 or S2* or G?
X'Y - Affected grandfather, ? - unknown genotype, * - May or may not get the trait (50% chances being a recessive trait)
Hope this information will clear your doubts about the topic.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
Regards