# Pedigree Analysis Using Punett Squares

Pages: 3 (543 words) Published: December 3, 2014
﻿Name: Megan Jackson
Date: November 20,2014
Lab Report
You may wish to construct the Punnett squares on scratch paper first before you fill in the Punnett squares on the Lab Report. Answer the questions below. When you are finished, submit this assignment to your teacher by the due date for full credit. Part 1: Monohybrid Cross—Predicting Freckles in an F1 Generation Apply your understanding of how alleles assort and combine during reproduction to evaluate a scenario involving a monohybrid cross. The allele for having freckles (F) is dominant over the allele for not having freckles (f). Some characteristics in people are inherited as simple dominant and recessive traits. One example is freckles. Freckles is a dominant trait, and the lack of freckles is a recessive trait. In this example, a person with freckles is represented as either FF or Ff, and a person with no freckles is represented as ff. (2 points)

1. Imagine a mother and a father who both have freckles and are heterozygous for the trait, or Ff. They are the P generation, or parent generation. Create a Punnett square to show their offspring, the F1 generation. Answer:

Part 1 Punnett Square

F
f
F
FF
Ff
f
Ff
ff
(2 points)
2. Calculate the ratios of the genotypes and phenotypes of the offspring in the F1 generation. Answer:
Genotypes: FF ¼, Ff ½, ff ¼
Phenotypes: Freckles ¾, No freckles ¼
Part 2: Dihybrid Cross—Predicting Flower Color and Seed Shape Imagine that you are crossing two plants that are heterozygous for flower color and seed shape. The dominant and recessive alleles for these traits are as follows: purple flowers: P

white flowers: p
round seeds: R
wrinkled seeds: r
(2 points)
1. Determine the genotype of each parent plant and write them below. Answer:
Genotype of parent plant 1: PpRr
Genotype of parent plant 2: PpRr
(4 points)
2. How will the alleles for these traits assort into the gametes that each parent might produce? (Hint: For a reminder on...