Genetic Diagram!

Genetics as it applies to evolution, molecular biology, and medical aspects.

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Joined: Tue Apr 14, 2009 6:05 pm

Genetic Diagram!

Post by bearcub » Tue Apr 14, 2009 6:20 pm

Is this right? Please can someone have a look at it?

In guinea pigs, hair length and colour are controlled by two genes on different chromosomes. The hair may be either long or short and its colour either black or brown.
A male guinea pig and a female guinea pig both had short, black hair.
The male was homozygous for hair length and the female was homozygous for hair colour. Repeated crossings of these two guinea pigs resulted in offspring of four different genotypes, all of which had short, black hair.
Complete the genetic diagram to explain these results. Write in the box the symbols you will use to represent the alleles

Allele for short hair: S Allele for long hair: s
Allele for black hair: B Allele for brown hair: b

Male Female
Parental phenotypes: Short, black hair. Short, black hair.
Parental genotypes: Male SSBb Female SsBB
Gamete genotypes: Male SB, Sb Female SB, sB

Offspring genotypes: SSBB, SSBB, SsBB, SsBb
Offspring phenotypes: Short, black hair.

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