Genetics answers – need help with this lab report
Genetics answers - need help with this lab report Lab_6_Genetic_crosses_Spring_2014.doc Download Attachment This is an unformatted preview. Please download the attached document for the original format. 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)