The diagram shows a pair of homologous chromosomes during meiosis in a cell in the human testis. The positions of the alleles of some genes are indicated.
(a) (ii) Identify in your diagrams in [i] which chromosomes are recombinant.
Important Questions on Genetics and Evolution
The diagram shows a pair of homologous chromosomes during meiosis in a cell in the human testis. The positions of the alleles of some genes are indicated.
(b) Explain the consequence of crossing over on variability.
Two genes determine the coat colour in mice. One gene controls whether the coat is coloured and the other controls the colour. The gene for coloured (C) is dominant over non-coloured or albino (c). Agouti (A) is for grey-coloured hair and is dominant over black (a). Albino mice (cc) do not have coat colour because these mice are unable to produce any colour.
a) Using a Punnet square, predict the possible genotypes for colour of coat of the offspring of a crossing of two agouti mice heterozygous for both genes.
Two genes determine the coat colour in mice. One gene controls whether the coat is coloured and the other controls the colour. The gene for coloured (C) is dominant over non-coloured or albino (c). Agouti (A) is for grey-coloured hair and is dominant over black (a). Albino mice (cc) do not have coat colour because these mice are unable to produce any colour.
(b) ldentify the possible phenotypes for the offspring in (a).
