In humans, free earlobe are dominant to attached earlobe, and a straight thumb is dominant to a hitchhikers thumb. Cross two people that are heterozygous for both traits.

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.

the answer is b. glad to .

your spelling is a little off : ]