In humans, free earlobe are dominant to attached earlobe, and a straight thumb is dominant to a hitchhikers thumb. Cross two peo
ple that are heterozygous for both traits.
1 answer:
Answer:
The correct answer is - the phenotypic ratio would be 9:3:3:1.
Explanation:
The two traits that are dominant are free earlobe and straight thumb that are denoted by the E and T on their alternative recessive alleles attached lobe and hitchhiker thumbs denoted by the e and t respectively. The heterozygous condition will be EeTt.
The cross between EeTt and EeTt will produce gametes ET, Et, eT, and et by each. The phenotypic ratio of the cross would be 9:3:3:1, which means 9 out of 16 offspring will be dominant in both trait, 3 will be free lobe and hitchhiker thumb, 3 will be straight thumb and attached earlobe, and 1 will be recessive in both traits. For the cross please check the attached image.
Thus, the correct answer is - the phenotypic ratio would be 9:3:3:1.
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