If a man who is heterozygous for hitchhiker's thumb marries a woman who is also heterozygous for hitchhiker's thumb, predict the potential genotypes and phenotypes for the offspring for that trait

Hitchhicker's thumb is a condition in which a person is able to bend his thumb backwards. This trait can be seen in many people but the condition is recessive, which means a person needs two alleles for  hitchhiker's thumb to have this particular characteristics. The gene for straight thumb is commonly indicated by T while that for hitch hicker's thumb is indicated by t.

Let's see what will happen if a person heterozygous for hitchhiker's thumb marries a woman who is also heterozygous for hitchhiker's thumb.

P1:                       Tt                X             Tt

Gametes:            t    T            :      t        T

Offsping :          TT    :     Tt     :       tT      : tt

TT    :        25 % :     Straight thumb

Tt + tT :    50% :      Straight thumb

tt :              25% :      Hitch hicker's thumb

Therefore, there are 25 % chances that their offspring will have Hitch hicker's thumb and 75 % chances that they will have straight thumb.

Hope it help!

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