Biology 9700 · AS & A Level · Passage of information from parents to offspring
Passage of information from parents to offspring — practice question
In cats, coat colour is controlled by a sex-linked gene that has two alleles for black or orange.
If black cats are mated with orange cats:
• all female offspring are tortoiseshell (black and orange patches)
• all male offspring have the same colour as their mother.
(a)[2]
Explain the meaning of a sex-linked gene.
(b)[4]
With $B$ representing the allele for black coat and $O$ representing the allele for orange coat, complete the genetic diagram below.
(c)[2]
Explain why tortoiseshell coat cannot occur in a male cat.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Gene is located on the X chromosome” …