The ability to roll your tongue and having freckles are both autosomal dominant traits.A woman who cannot roll her tongue, and is heterozygous for having freckles mates with a man who is homozygous dominant for both traits.

7)What are the chances of this couple having a child who is homozygous dominant for both traits?

8)Heterozygous for both traits?

9)Homozygous recessive for both traits?

10)Heterozygous for one of the 2 traits?

Question

The ability to roll your tongue and having freckles are both autosomal dominant traits.A woman who cannot roll her tongue, and is heterozygous for having freckles mates with a man who is homozygous dominant for both traits.

7)What are the chances of this couple having a child who is homozygous dominant for both traits?

8)Heterozygous for both traits?

9)Homozygous recessive for both traits?

10)Heterozygous for one of the 2 traits?

anonymous · Answer

Since it would only take one faulty gene for the person to be affected. I assume that the woman has a normal gene pair for tongue rolling. This fact combined with the man's homozygous genes would produce:

7) No chance for homogeneity of both traits-- Genes for the ability to roll tongue will be 100% hetrozygous. 

8) 1 in 2 chances for both traits to be heterozygous.

9) No recessive trait because of the autosomal dominance.

10) 1 in 2 chances to be heterozygous in one of the two traits.