Explore BrainMass

Mendel Genetics Problems

Please see attached word document.

Assignment Part I - Mendelian Genetics (7.5 pts).
Information on the analysis of crosses and Chi-square statistics are available under the supplemental reading section of the course website. Below is the Chi-square probability table at 0.05 (5%)

Degrees of Freedom Reject the null hypothesis if the calculated chi-square is larger than
1 3.841
2 5.991
3 7.815
4 9.488
5 11.070

1. An organism with genotype AaeeDd can make how many different gametes (list each one)? (1 pt)

2. You are studying one trait that is autosomal recessive. You crossed the following true breeding parents: autosomal dominant female with an autosomal recessive male. Draw the Punnett square and provide the expected genotypic and phenotypic ratios in the F2 generation? (1.25 pt)

3. You hypothesize that you have one autosomal dominant trait. You crossed the following true breeding parents: wild type female and mutant male. In the F2 generation you observe the following phenotypes: 35 dominant females, 35 dominant males, 20 recessive males, and ten recessive females. Show your chi-square calculations, and does this fail to reject the stated hypothesis? (1 pt)

4. What is the genotypic ratio of the progeny produced from this mating?
Parental cross: female aaBb crossed with a male AABb

5. You are studying hair length in wild yaks and perform the standard genetic crosses. From the following observations provide a hypothesis of how this trait is inherited (which allele is dominant and whether it is autosomal or sex-linked). Assume both parents are true breeding. Test your hypothesis with a Chi-square test. Show all your calculations for the Chi-Square. (1.5 pt)
P: short haired male X long haired female
F1: 145 long haired males and 155 short haired females
(F2 is a cross of F1 male and female)
F2: 73 long haired females; 77 short haired females; 72 long haired males, 78 short haired males.

6. You are analyzing a dihybrid cross where both mutant traits are autosomal recessive in a Scooby Doo species. You set up the cross with each true breeding parent exhibiting one wild type trait. You observe A = brown, a = gray and M = munchies, m = no munchies. In the F2 generation you observe 152 brown munchie having scoobys, 48 brown no munchie having scoobys, 42 grey munchie having scoobys and 12 grey no munchie having scoobys.
a. Draw the Punnett squares for F1and F2. (.5 pt)
b. What is the expected number of each F2 phenotype (show work) (1 pt)
c. Does Chi-square support the null hypothesis? (show your work) (.75 pt)


Solution Preview

I looked at the attached Word document as you requested. I'm not sure what you ...