GENETICS The ability to curl your tongue up on the sides Is

The ability to curl your tongue up on the sides Is dominant to not being able to roll your tongue. A woman who can roll her tongue marries a man who cannot roll his tongue. Their first child has his father\'s phenotype. What are the genotypes of the Mother ___ Father ___Child____ What\'s the probability a second child won\'t be a tongue roller? _____ Explain why below: The common grackle, Quiscalus quiscula, is a species of robin-sized blackbirds that is common in Atlantic Canada. In grackles, long tails (S) are dominant to short tails (s). A short-tailed female grackle is mated with a long-tailed male grackle that had one parent with a long tail and one parent with a short tail. What is the genotype of the male? ____ Assuming 4 hatchlings, how many of each genotype would be present in the Fi generation? SS____ Ss____ ss____ How many of each phenotype would be present in the F_1 generation? long tail____ short tail_____

Solution

3.

Since the child has recessive cahracter, that is he/she can\'t roll the tongue, that means the mother is heterozygous.

Let \'T\' be the dominant allele and \'t\' be the recessive allele.

Genotype of the mother is : Tt

Genotype of the father is: tt

The probability of the second child won\'t be a tongue roller is : 1/3

Punett square analysis: Tt x tt

Since one child already is not a tongue roller, so the probability of second child to be a non tongue roller is: 1/3

	T	t
t	Tt (Tongue roller)	tt (not a tongue roller)
t	Tt (Tongue roller)	tt (not a tongue roller)