Explore BrainMass

Punnett Square Explanation and Solving With Genetics

2.Punnett square for 2 genes that affect pod shape (inflated or wrinkled) and flower position (on stem or at tip)in garden peas. One gene has alleles for inflated (A) and wrinkled (a) traits, where inflated is dominant. The other gene has alleles for on stem (B) and at tip (b) traits, where on stem is dominant. In a cross between 2 parents, one of which is heterozygous for both genes and the other is homozygous recessive for both genes, the simulation will use the square to predict the ratio of their offspring that would have wrinkled pods AND have flowers on the stem. Draw the aquare and explain the cross.

© BrainMass Inc. brainmass.com July 16, 2018, 8:27 pm ad1c9bdddf

Solution Preview

A=inflated, a=wrinkled; inflated is dominant
<br>B=on stem, b=at tip; stem is dominant
<br>parent 1 heterozygous for both genes: AaBb
<br>parent 2 homozygous recessive for both genes: aabb
<br>Some key definitions: Homozygous means it has the same alleles (either aa or AA). Heterozygous means it has different alleles (Aa). If a trait is recessive, then in order to have the recessive ...