NEET BIOLOGY

Detailed explanation-1: -A woman who does not have hitchhiker’s thumb marries a man who is heterozygous for hitchhiker’s thumb. What is the probable genotypic ratio of their children. Genotype is the allelic combination of the trait. The the probable genotypic ratio (Hh:hh) of their children is 1:1.

Detailed explanation-2: -A person born with the “Ss” genotype will have a straight thumb, but will also be a bearer of the hitchhiker’s thumb. A person born with an “SS” genotype will only have a straight thumb and no chances for having the condition of the hitchhiker.

Detailed explanation-3: -Hitchhiker’s thumb is a thumb that’s hypermobile, or very flexible, and able to bend backward beyond the normal range of motion. Known formally as distal hyperextensibility, this condition isn’t painful and doesn’t inhibit the thumb’s function in any way.

Detailed explanation-4: -The allele for a hitchhiker’s thumb is recessive compared to straight thumbs, which are dominant. In a population of 1000 individuals, 680 show the dominant phenotype.

Detailed explanation-5: -Here, Glass and Kistler define a Hitchhiker’s Thumb to be a thumb that bends more than 50 degree. In their study between 24.7% and 35.6% of individuals in the United States have a Hitchhiker’s Thumb.