In humans, polydactyly (i.e. presence of extra fingers and toes) is determined by a dominant autosomal allele (P) and the normal condition is determined by a recessive allele (p). Find out the possible genotypes of family members 1, 2 and 3 in the given pedigree.

Question

In humans, polydactyly (i.e. presence of extra fingers and toes) is determined by a dominant autosomal allele (P) and the normal condition is determined by a recessive allele (p). Find out the possible genotypes of family members 1, 2 and 3 in the given pedigree. <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/b-zpraftkcbqg2o8c8.jpg" /> (A) 1 2 3 PP Pp pp (B) 1 2 3 PP PP pp (C) 1 2 3 Pp PP Pp (D) 1 2 3 Pp Pp pp

Tardigrade Admin · Accepted Answer

Pedigree analysis provides information regarding inheritance of particular traits or diseases and using it we can predict the possibility of appearance of any traits in the new generation.
Member 3 is unaffected and the normal condition is recessive thus its genotype will be pp. To obtain recessive homozygous condition, both parents must have the recessive allele, therefore, member 2 must be heterozygous as it is affected one. Genotype of member 2 is Pp.
Member 1 genotype is also Pp as the son is unaffected (pp) and the wife of member 1 is normal.

$1$	$2$	$3$
$PP$	$Pp$	$pp$

$1$	$2$	$3$
$PP$	$PP$	$pp$

$1$	$2$	$3$
$Pp$	$PP$	$Pp$

$1$	$2$	$3$
$Pp$	$Pp$	$pp$

Q. In humans, polydactyly (i.e. presence of extra fingers and toes) is determined by a dominant autosomal allele (P) and the normal condition is determined by a recessive allele (p). Find out the possible genotypes of family members 1, 2 and 3 in the given pedigree.

1 2 3 PP Pp pp

1 2 3 PP PP pp

1 2 3 Pp PP Pp

1 2 3 Pp Pp pp

$1$ $2$ $3$

$PP$ $Pp$ $pp$

$1$ $2$ $3$

$PP$ $PP$ $pp$

$1$ $2$ $3$

$Pp$ $PP$ $Pp$

$1$ $2$ $3$

$Pp$ $Pp$ $pp$