contestada

In humans, almond shaped eyes are dominant to round shaped eyes and long eyelashes are dominant to short. A man who has round eyes and homozygous long eyelashes marries a woman who is heterozygous for both traits. Determine the phenotypic ratio. If they have 8 children, how many will have almond shaped eyes with long eyelashes?

Respuesta :

The phenotypic ratio is almond shaped long lashes : round shaped long lashes : round shaped short lashes =2:1:1.

4 children will have long eyelashes and almond shaped eye.

Explanation:

Let the gene for eye shape be E and gene for eyelashes be L.

E denotes the almond shaped eye which is dominant over e which is round eye.

L denotes long eyelashes which is dominant over l which is short eyelash.

So genotype of man = eeLL

Genotype of woman = EeLl.

So gametes from man = eL.

Gametes from woman = EL, eL, El and el.

So the genotypic ratio of their children =

EeLL : EeLl: eeLl:eell = 1:1:1:1.

So, assuming these genes maintain the rule of complete dominance, the phenotypic ratio is almond shaped long lashes : round shaped long lashes : round shaped short lashes =2:1:1.

So among 8 children, children with almond shaped eye and long eyelashes will be 4.

Otras preguntas