Answer no 1)
The cross between a homozygous red bull (RR) and a heterozygous red cow can be made as follows:
R r
R RR Rr
R RR Rr
The results from the experiment show that 50% of the genotype will be homozygous for red colour and 50% of the population will be heterozygous for the red colour. The phenotype will be 100% red.
Answer No 2)
Cross between a heterozygous red bull (Rr) and a heterozygous red cow (Rr)
can be shown as follows:
R r
R RR Rr
r Rr rr
The results show that the genotype will be 25 % homozygous dominant, 50% heterozygous and 25% homozygous recessive. The phenotype will show 75% dominant trait (red) and 25% recessive trait (white).
Answer No 3)
The cross between a homozygous white bull (rr) and a homozygous white cow (rr) can be shown as follows:
r r
r rr rr
r rr rr
The results from the punnet square show that the genotype of all the offsprings will be homozygous recessive (rr) and the phenotype will be recessive ( white).
