Question

Directions: For the following questions, create a Punnett square. Be sure to show the genotypes, phenotypes, and percentages for each cross.

5. Mendel first made sure that he had purebred dominant green pod plants and then he crossed them with yellow pod plants. What is the probability that the offspring are green? 6. Second, Mendel used the offspring from the first cross and allowed them to self pollinate. What is the probability that the resulting offspring are yellow? 7. Fur color in animals is frequently controlled by more than one gene. However, brown fur in rabbits is dominant over white fur. A white female gives birth to all white rabbits, even though the father had brown fur. Show how this is possible.

Answer 1

5. cross-pollination between true-breeding green and yellow pods :

let genotype of true-breeding yellow pod be 'g' and genotype of true-breeding green pod be 'G'

Genotype: Gg Phenotype-green Genotype: Gg Phenotype: green Genotype: Gg Phenotype: green Genotype: Gg Phenotypes green

All plants of F1 generation will be hybrid (heterozygous)and will express dominant pod colour which is green.

6. self-pollinating first offsprings:

The genotype of heterozygous f1 generation green pod: 'Gg'

  

Genotype: Gg Phenotype: green Genotype: Gg Phenotype: green Genotype: Gg Phenotype: green Genotype: gg Phenotype: yellow

In F2, pods will appear in 3:1 ratio, three green and one yellow i.e. in F2, 75% probability to become green and 25% probability to become yellow.

7.

Multiple Alleles • Agouti rabbits - 4 alleles: C. ch.ch, -w/ dominance relationship to one another: C> cc> ch>C .agouti rabbit (wild type) - Phenotype: brown, Genotype: CC, CcohCch, or Cc • "Chinchilla" (mutant) - Phenotype: silvery gray, Genotype: coco, coch, or conc • "Himalayan" (mutant): - Phenotype: white w/ black points. Genotype: c'h orche • "Albino" (mutant) - Phenotype: white, Genotype: cc