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Name: Kiel Allen
Last 4 digits of student ID: 0914
Lab section: FZEC
Instructor name: _____________________
Lab 6: Genetic Crosses
Spring_2014
Read Chapter 7 and print out the sample genetic cross to use as a guide.
Below is a list of the Phenotypes used in this lab. These are all single gene traits that show
complete dominance
Trait
Flower color
Plant Height
Seed Shape
Seed Color

Dominant phenotype
Purple flowers
Tall plants
Smooth seeds
Yellow seeds

Recessive Phenotype
White flowers
Short Plants
Wrinkled seeds
Green seeds

Part I: Symbols and definitions:
1. a) What is an allele? Give an example of 2 alleles of any gene. (0.5 pts)
An allele is a trait of the gene. Individuals has two copies of each gene inherent from both
parents. Example of 2 alleles for a gene could be the blood type or eye color
b) What is the difference between an organism that is a homozygote and one that is a
heterozygote? (0.25 pts)
Homozygote individual inherits the same two alleles for this gene, and Heterozygote
individual inherits different alleles from each parent.
c) What is the difference between an organism’s genotype and its phenotype? (0.25 pts)
The Phenotype is the outward appearance of an individual, and the Genotype is the
organism’s genetic composition.
2.) For each trait indicate the genotypes that are possible. Use the first letter of the dominant trait
to indicate the trait. (2pts)
Trait
Flower color
Plant Height

Dominant genotype(s)
Purple =
Tall =

Recessive genotype(s)
White =
Short =

Seed Shape
Seed Color

Smooth =
Yellow =

Wrinkled =
Green

Pick three of the crosses to complete using any 3 of the last 4 digits of your student ID. If
there are repeats, pick random numbers, so you are doing 3 different crosses. Circle the
numbers of the crosses you are doing in column 1 below.
You must pick 3 different crosses. If there are multiple repeated numbers in your ID, pick
additional numbers of your choice.
Cross
Number
0
1
2
3
4
5
6
7
8
9

Male parent traits

Female parent traits

Heterozygous for flower color
Homozygous dominant for height
Heterozygous for flower color
Heterozygous for height
Heterozgyous for flower color
Heterozygous for seed color
Homozygous recessive for flower color
Heterozygous for seed color
Homozygous recessive for seed shape
Homozygous recessive for height
Heterozygous for seed shape
Heterozygous for height
Homozygous dominant for flower color
Homozygous recessive for seed shape
Heterozygous for flower color
Homozygous recessive for seed shape
Heterozygous for seed shape
Homozygous recessive for seed color
Heterozygous for seed shape
Heterozygous for seed color

Heterozygous for flower color
Homozygous dominant for height
Homozygous dominant for flower color
Heterozygous for height
Heterozgyous for flower color
Heterozygous for seed color
Homozygous dominant for flower color
Heterozygous for seed color
Heterozygous for seed shape
Heterozygous for height
Heterozygous for seed shape
Homozygous recessive for height
Homozygous recessive for flower color
Homozygous dominant for seed shape
Heterozygous for flower color
Homozygous recessive for seed shape
Homozygous recessive for seed shape
Homozygous recessive for seed color
Homozygous recessive for seed shape
Homozygous dominant for seed color

Now you can use the charts and Punnett squares on each of the following pages to complete
your crosses.

Cross 1: Please write the number of the cross you are performing: ______________
Then fill in the genotype and phenotype for each parent below. Use the sample problem for a
guide.
Sex
Male
Female

Genotype

Phenotype

Step 1: Determine the different gamete combinations that each parent can contribute to the
offspring. Check the hint from the sample problem when you are doing this.

Sex
Male
Female

Gamete 1

Gamete 2

Gamete 3

Gamete 4

Step 2: Fill in the Punnett Square below
Male gametes
place across ?
Female Gametes:
Place below: ?

Step 3: Find the Phenotype of each of the 16 combinations in your Punnett Square page.
Phenotype you’ve found in offspring

Number of offspring with this phenotype

Cross 2: Please write the number of the cross you are performing: ______________
Then fill in the genotype and phenotype for each parent below.
Sex
Male
Female

Genotype

Phenotype

Step 1: Determine the different gamete combinations that each parent can contribute to the
offspring.
Sex
Male
Female

Gamete 1

Gamete 2

Gamete 3

Gamete 4

Step 2: Fill in the Punnett Square below
Male gametes
place across ?
Female Gametes:
Place below: ?

Step 3: Find the Phenotype of each of the 16 combinations in your Punnett Square page.
Phenotype you’ve found in offspring

Number of offspring with this phenotype

Cross 3: Please write the number of the cross you are performing: ______________
Then fill in the genotype and phenotype for each parent below.
Sex
Male
Female

Genotype

Phenotype

Step 1: Determine the different gamete combinations that each parent can contribute to the
offspring.
Sex
Male
Female

Gamete 1

Gamete 2

Gamete 3

Gamete 4

Step 2: Fill in the Punnett Square below
Male gametes
place across ?
Female Gametes:
Place below: ?

Step 3: Find the Phenotype of each of the 16 combinations in your Punnett Square page.
Phenotype you’ve found in offspring

Number of offspring with this phenotype

Questions:
1. Are gametes haploid or diploid? What about the offspring, are they haploid or diploid? (1pt)

2. A) Can two tall and smooth seeded parents produce offspring that are short and have wrinkled
seeds? (To receive a full credit for this assignment you MUST explain your answers for part A
and part B by drawing the respective Punnett squares for each of your answers).
Explain using a Punnett square why you think this outcome is possible or not. (1pt)

B) Can two white flowered and green seeded parents produce offspring that have Purple
flowers and have yellow seeds?
Explain using a Punnett square why you think this outcome is possible or not. (1pt)