Solved by a verified expert: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)
Recent Comments