Problem Set 3- Due in class on Friday 9/24

1.  Why did the discovery that the white kerneled wheat occurred 
in 1/64 of the F2 of a true-breeding cross between a red-kerneled 
and a white kerneled strain of wheat lead to the acceptance 
that quantitative traits are controlled by mendelian inheritance?  
What is special about the figure 1/64?  Use the forked line 
approach to calculate the genotypic frequency in the F2 of the 
triple homozygous recessive in the following cross:
			AABBCC x aabbcc

2.  The Human ABO blood system is controlled by an allelic series.
Is this an additive allelic series?  Explain.

3.  You cross a tortoiseshell (black and orange) female cat with 
a black male cat.  Both cats are manx (short tail).  Calculate 
the phenotypic ratios of all possible live-born offspring 
from this cross.  Remember:  the gene for coat color has 
two alleles:  orange (O) and black (O+) and it is X-linked;  
the allele that causes short tails (M) is dominant and is 
a homozygous lethal.  These genes are NOT linked.  Use the 
Punnet Square method to do this cross.

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