Moderate

In cats, the genes controlling coat color are co-dominant and are carried on the X chromosomes. When a black female was mated with a ginger male the resulting litter consisted of black male and tortoise-shell female kittens. What phenotypic ratio would be expected in the F2 generation?

Correct answer: B. 1 black male : 1 ginger male : 1 tortoise - shell female : 1 black female

  • A. 1 black male : 1 ginger male : 2 tortoise - shell females
  • B. 1 black male : 1 ginger male : 1 tortoise - shell female : 1 black female
  • C. 2 black males : 1 tortoise - shell female : 1 ginger female
  • D. 1 black male : 1 tortoise - shell female : 1 ginger female : 1 black female
  • E. 2 black males : 1 tortoise - shell female : 1 black female

Explanation

A black male has a genotype of XbY Tortoise-shell female kittens will have: XbXg XbY and XbXg XbXb; XbXg; XbY; XgY Hence: 1 Black-female; 1 tortoiseshell female; 1 black male; 1 ginger male.

Last updated

About Inheritance

Mendel's laws explain segregation, independent assortment and the prediction of genetic ratios using alleles, genotypes and phenotypes. The chapter also covers linked genes, recombination and crossing over during meiosis, then applies pedigree reasoning to X-linked recessive traits, which show different inheritance patterns in males and females.

Practise Inheritance

1,238 free Inheritance MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Biology questions like this

Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions