Biology 1010: Spring 2017 Laboratory Six: Genetic Crosses

11 Jun Biology 1010: Spring 2017 Laboratory Six: Genetic Crosses

Question
Biology 1010: Spring 2017

Laboratory Six: Genetic Crosses

Lab section: FEAB

Direction:There is no simulation for this report. Completion of this lab report will be based onreading Chapter 7 and using the word file entitledLab 6 Handout: Sample Genetic Crosses posted on Launchpad as a guide.

Table 1: Below is a list of the phenotypes used in this lab. These are all single gene traits that show complete dominance. Use this information to set up and analyze your crosses.

Trait

Dominant phenotype

Recessive Phenotype

Flower color

Purple flowers

White flowers

Plant Height

Tall plants

Short Plants

Seed Shape

Smooth seeds

Wrinkled seeds

Seed Color

Yellow seeds

Green seeds

Part One: Symbols and definitions:

1. Short answer questions:

a. What is a gene? (0.25pts)

A gene is a unit of heredity that is passed on from a parent to its offspring and is used to determine the characteristics of the offspring.

b. What is an allele? Give an example of 2 alleles of a human gene. (0.25 pts)

An allele is a trait of the gene. Individuals have two copies of each gene inherent from both parents; examples of this could include things like the offspring’s blood type, hair or eye color, etc.

c. What is the difference between an organism that is a homozygote and one that is a heterozygote? (0.25 pts)

A homozygote is an individual organism with two copies of the same allele that determines a specific trait, while a heterozygote has a copy of two different alleles for the same trait.

d. What is the difference between an organism’s genotype and its phenotype?(0.25 pts)

An organism’s phenotype would be the outward appearance of that individual, where the genotype would be the organism’s genetic composition.

2. For each trait in the table below, indicate ALL OF THEGENOTYPESthat are possible. Use the first letter of the dominant trait to indicate the trait. (2pts)

Trait

Dominant genotype(s)

Recessive genotype(s)

Flower color

Purple = PP Pp pP

White = pp

Plant Height

Tall = TT Tt tT

Short = tt

Seed Shape

Smooth = SS Ss sS

Wrinkled = ss

Seed Color

Yellow = YY Yy yY

Green= yy

Part Two:Genetic Crosses

1. Pick three of the crosses to complete using any 3 of the last 4 digits of yourCUNYFirst Empl ID. If there are repeats, pick random numbers, so you are doing 3different crosses.

2. Highlight the numbers of the crosses you are doing in column 1 below. You must pick 3different crosses.

Cross Number

Male parent traits

Female parent traits

0

Heterozygous for flower color

Heterozygous for height

Homozygous dominant for flower color

Heterozygous for height

1

Heterozygous for flower color

Homozygous dominant for height

Heterozygous for flower color

Homozygous dominant for height

2

Heterozygous for flower color

Heterozygous for seed color

Heterozygous for flower color

Heterozygous for seed color

3

Homozygous recessive for flower color

Heterozygous for seed color

Homozygous dominant for flower color

Heterozygous for seed color

4

Homozygous recessive for seed shape

Homozygous recessive for height

Heterozygous for seed shape

Heterozygous for height

5

Heterozygous for seed shape

Heterozygous for height

Heterozygous for seed shape

Homozygous recessive for height

6

Homozygous dominant for flower color

Homozygous recessive for seed shape

Homozygous recessive for flower color

Homozygous dominant for seed shape

7

Heterozygous for flower color

Homozygous recessive for seed shape

Heterozygous for flower color

Homozygous recessive for seed shape

8

Heterozygous for seed shape

Heterozygous for seed color

Homozygous recessive for seed shape

Homozygous dominant for seed color

9

Heterozygous for seed shape

Homozygous recessive for seed color

Homozygous recessive for seed shape

Homozygous recessive for seed color

1. Now you can use the charts and Punnett squares on each of the following pages to complete your crosses. You can use the Lab 6 Handout: Sample Genetic Cross posted on LaunchPad directly below the lab for a guide in doing these 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 of a genetic cross posted on LaunchPad directly below the lab for a guide.

Sex

Genotype

Phenotype

Male

Female

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

Gamete 1

Gamete 2

Gamete 3

Gamete 4

Male

Female

Step 2: Fill in the Punnett Square below

Male gametes place across à

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

Genotype

Phenotype

Male

Female

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

Sex

Gamete 1

Gamete 2

Gamete 3

Gamete 4

Male

Female

Step 2: Fill in the Punnett Square below

Male gametes place across à

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

Genotype

Phenotype

Male

Female

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

Sex

Gamete 1

Gamete 2

Gamete 3

Gamete 4

Male

Female

Step 2: Fill in the Punnett Square below

Male gametes place across à

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

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