Pls pls pls experts give a proper way and tricks to solve these types of questions...
Dear Student
In this case, you can see that the son (III) is showing a particular trait. As none of the parents are showing the trait, it means that either it's an autosomal recessive with both parents as carriers or it is an X-linked trait with the mother as a carrier. The father cannot be the carrier because males only have 1 X and if it's X-linked the father would also show the trait.
Now if we see the options, it's clear that this is an X-linked disorder.
Now as the daughter (II) is not showing the trait as seen in the pedigree chart, she can either be XX or XXc.
For the son (III) we know he is showing traits and we have established that it's an X-linked trait, and as males only have 1 X chromosome the genotype can only be Xc Y.
So now our answer can be
Genotype of
II - XX or XXc
III - Xc Y
If we look at the options only Option 1 is possible.
Therefore the answer is Option (1)
Regards
In this case, you can see that the son (III) is showing a particular trait. As none of the parents are showing the trait, it means that either it's an autosomal recessive with both parents as carriers or it is an X-linked trait with the mother as a carrier. The father cannot be the carrier because males only have 1 X and if it's X-linked the father would also show the trait.
Now if we see the options, it's clear that this is an X-linked disorder.
Now as the daughter (II) is not showing the trait as seen in the pedigree chart, she can either be XX or XXc.
For the son (III) we know he is showing traits and we have established that it's an X-linked trait, and as males only have 1 X chromosome the genotype can only be Xc Y.
So now our answer can be
Genotype of
II - XX or XXc
III - Xc Y
If we look at the options only Option 1 is possible.
Therefore the answer is Option (1)
Regards