Manx cats with two recessive alleles have a tail. Heterozygous Manx cats lack a tail. Individuals with both dominant alleles die before birth.

Which answer shows the percentage of Manx cats without tails in a population for the two crosses given in the table?

Answer:

25) C

Manx cat with a tail x Manx cat without a tail

t t

T Tt Tt

t tt tt

Manx cat without tail = 50%

Manx cat without a tail x Manx cat without a tail

T t

T TT (dead) Tt (67%)

t Tt (67%) tt (33%)

Manx cat without tail = 67%

Hence, C is the answer.