I want tagarwal to answer this
Plant Genetics questions

Lab Report

Name: _______________________
Section: _____________________

Plant Genetics
Exercise 1 - The Punnett Square
1. Write a hypothesis describing the phenotype of the germinating tobacco seeds. Include the
approximate number of seedlings and percentages that will have a dominant trait and
recessive trait out 50 seeds.

2. Create a Punnett square using Data Table 1, showing the possible F2 generation outcomes
from a cross between a heterozygous male and a heterozygous female for the germinating
tobacco seeds. The dominant allele is written as “G” for green and the recessive allele for
albino/yellow color is written as “g”.

Data Table 1: Hypothetical Punnett Square
Father ( ____ ____ ) x Mother ( ____ ____)

Father ?
Mother ?
Gametes

3. Count the number of seedlings that are green versus those that are yellow and record the data
in Data Table 2.

Data Table 2 – Seedling data
Seedling Color
Green

Yellow

Number of
Seedlings

1

Total

Percentage of
Total

4.

Compare the expected outcome to actual results found in Data Table 2, write this
information into Data Table 3.
Data Table 3 – Frequency calculations
Frequency

Expected Values

Actual Values

Green
Yellow
Total

Questions:
5.

What are the predicted ratios of the phenotypes (green to yellow) in the plants?

6. What were the actual ratios of the phenotypes (green to yellow) displayed in the tobacco
plants?

7. If all yellow seedlings were removed from the population, would the next generation still
have a chance at displaying the yellow allele? Explain your answer.

8. Would a cross between a homozygous and a heterozygous parent show the same ratios?

9. Explain why it may be important to collect data from a larger population.

Lab Report

Name: _______________________
Section: _____________________

Exercise 2 – Dihybrid Crossing with Corn
1. Count the number of purple, yellow, smooth and wrinkled seeds on the ear of corn between
the lines in Figures 4-7 and record the data in Data Table 4.
Data Table 4 – Corn kernel data
Number of Kernels

Kernel Percentage (divide count
by total, then multiply by 100)

Kernel Coloration
Purple
Yellow
TOTAL

Kernel Texture
Smooth
Wrinkled
TOTAL

2. The ear of corn is a result of a cross between plants that were both heterozygous for color and
texture. Write the genotypes of both parents of this dihybrid cross. (P = purple color; p =
yellow color; S = smooth shape; s = wrinkled shape)

3. What are the possible gametes for both parents? (Place these gametes into the Punnett square
in Data Table 5 for both the male and the female.)

4. Calculate the phenotypic ratios that are expected for each type of seed.
a. Purple & smooth ______________________
b. Purple & winkled _____________________
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c. Yellow & smooth _____________________
d. Yellow & wrinkled ____________________
Data Table 5 – Punnett square for dihybrid cross
Parent Gametes ?
Gametes
Parent
Gametes ?

5. Calculate the expected percentage of:
a. Purple, smooth kernels ________________________
b. Purple, wrinkled kernels _______________________
c. Yellow, smooth kernels ________________________
d. Yellow, wrinkled kernels _______________________
6. Count the number of purple/smooth; purple/wrinkled; yellow/smooth and yellow/wrinkled
kernels on the quarter ear of corn and record the numbers in Data Table 6.
Data Table 6 – Data from corn kernels
Number Counted

Ratio: Number
counted/total

Purple and smooth
Purple and wrinkled
Yellow and smooth
Yellow and wrinkled
TOTAL

Questions
7. What are the probable coloration phenotypes of the corncob parents?
8. What are the probable texture phenotypes of the corncob parents?
9. Was the ratio calculated in Data Table 6 equal to 9:3:3:1? If not, given a possible

Lab Report

Name: _______________________
Section: _____________________

explanation as to why not.

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