Exercise 3_KEY_FINAL_2013_6FEb

# Exercise 3_KEY_FINAL_2013_6FEb - 1 Ecology 335 Evolutionary...

This preview shows pages 1–2. Sign up to view the full content.

1 Ecology’335,’ Evolutionary Biology ,’2013 ’ Exercise’ 3.’Due’Feb’4 ’ at’11’am. ’ Multilocus genotypes, linkage, genetic drift and mutation rate. 1. For 20 loci each with 2 alleles each: a. How many haplotypes (gamete types, sperm or eggs) are possible? 1,048,576 gamete types are possible. This is as simple as raising 2 to the 20 th power. b. How many diploid genotypes (zygotes) are possible? 3,486,784,401 genotypes are possible. Remember that there are three possible genotypes for each locus (two homozygous, one heterozygote), and there are 20 loci. So raise 3 to the 20 th power. 2. You cross an abC haploid genotype with an ABc haploid genotype and obtain the following haploid progeny: ABC ABc AbC Abc aBC aBc abC abc 0 100 0 100 100 0 0 100 a. Are A and B loci in linkage equilibrium with each other (show your work)? Yes: A and B, A and b, a and B and a and b occur in equal frequencies OR you can plug in the equation for LD: LD = Freq (AB) x Freq (ab) – Freq (Ab) x Freq (aB) = (0.25 x 0.25) - (0.25 x 0.25) = 0 b. Are A and C loci in linkage equilibrium with each other (show your work)? No: There are no AC combinations. Using the equation for LD: LD = Freq (AC) x Freq (ac) – Freq (Ac) x Freq (aC) = (0 x 0.25) - (0.50 x 0.25)= -0.125 c. Are B and C loci in linkage equilibrium with each other (show your work)? No: There are no bC combinations. Using the equation for LD: LD = Freq (BC) x Freq (bc) – Freq (bC) x Freq (Bc) = (0.25 x 0.5) - (0 x 0.25) = 0.125 d. Can you determine if these three loci are physically linked given the data? Nothing definitive, although two are in LD, they may or may not be on the same chromosome, however.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 4

Exercise 3_KEY_FINAL_2013_6FEb - 1 Ecology 335 Evolutionary...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online