Question
(a) What is a hybrid? (b) if a hybrid black haired Guineapig is crossed with a white haired Guineapig, what will be the phenotypes of the Guineapigs of the First filial (F₁) generation and why-Explain with reasons.
Answer
(a) A hybrid is an organism that has two different alleles for a particular trait. These alleles can be different versions of the same gene, such as one for tallness and one for shortness.
(b) If a hybrid black haired guinea pig (Bb) is crossed with a white haired guinea pig (bb), the phenotypes of the guinea pigs in the F1 generation will all be black haired (Bb). This is because black hair (B) is a dominant trait over white hair (b), so even if only one of the alleles is for black hair, it will be expressed in the phenotype. However, all of the F1 guinea pigs will be carriers for the recessive white hair allele (b) since they inherited it from the white haired parent. Therefore, the F2 generation resulting from a cross between two F1 guinea pigs will have a 3:1 phenotypic ratio of black haired to white haired guinea pigs.
