Attached earlobes are recessive to free earlobes. if two heterozygous individuals have a child, what is the probability of the child having attached earlobes?

probability of the child having attached earlobes since it is recessive i.e (yy)

=1/4

=0.25 × 100%

=25%

Explanation:

If two heterozygous individuals have a child

i.e let the heterozygous individuals be  = Xy

if both traits crosses together; their F₁ offspring will be;  (XX, Xy, Xy, yy)

Xy  ×   Xy

          X             y

X        XX          Xy

y       Xy            yy

probability of the child having attached earlobes since it is recessive i.e (yy)

=1/4

=0.25 × 100%

=25%

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).