Question

8. Two rabbits are bred together. One is heterozygous for agouti coat

Answer 1

Answer:

- Parental cross = Cch  x chch  

- F1 = 1/2 Cch (agouti coat); 1/2 chch (albino coat) >> 1:1 phenotypic ratio

Punnett  square:  

          ch         ch

C       Cch       Cch

ch    chch      chch

 

Explanation:

A heterozygous individual is an individual who has two different gene variants (i.e., alleles) at a particular locus. In this case, individuals having the "agouti coat" trait are heterozygous carrying both 'C' and 'ch' alleles. On the other hand, a homo-zygous individual has the same allele at a given locus (here, the 'chch' genotype associated with the albino phenotype). Therefore, as observed in the Punnett Square above, when a heterozygous parent is crossed with a homo-zygous recessive parent for a single gene, alleles segregate in the gametes of both parents so an expected 1:1 phenotypic ratio will be observed.