Compose answers to the questions below and save the file as a backup copy in the event that a technical problem is encountered while attempting to submit the assignment. Make sure to run a spell check.
You will be submitting your answers to the lab assignment in two parts. The first part of the lab assignment consists of the laboratory exercise questions. The second part of the lab assignment is the application question. The first textbox on the submission page corresponds to the first part of the lab. Be sure to paste the laboratory exercise questions, with your answers, into this textbox. The second textbox on the submission page will be for your response to the application question.
LABORATORY EXERCISE QUESTIONS
Distinguish between the terms gene and allele. (1 point)
Give an example of one genetic trait (gene) and two different alleles (allele phenotypes) for that gene. (3 points)
Genetic Trait
Allele phenotype #1
Allele phenotype #2
Compare and contrast the terms phenotype and genotype. (4 points)
List the allele combinations (gamete possibilities) that can be formed by an individual with the following genotype: AABB (1 point)
List the different allele combinations (gamete possibilities) that can be formed by an individual with the following genotype: AaBb. (4 points)
Given: P = purple flowers and p = white flowers and P is dominant over p.
A horticulturist has a purple plant and a white plant. The horticulturist knows that purple is dominant over white. When they are bred, all of the resulting offspring are purple. What is the most likely genotype of the parent or original purple plant? (2 points)
A horticulturist runs a test cross with an offspring (F1 generation) purple plant from Question 8. The phenotypic frequencies of the resulting offspring are 50% white and 50% purple. What is the true genotype of this offspring (F1 generation) purple plant? (2 points)
What is the probability of a cross resulting in purple offspring when two heterozygous purple pea plants (e.g. Pp x Pp) are bred? What is/are the genotype(s) for purple offspring resulting from this cross? (4 points)
Compare the real-world ratios calculated in Exercises 5 and 6 (coin toss activity) to Mendel’s ratios. Were they close? Pose a possible explanation for why the ratios may not be exactly the same. (4 points)
Refer to the data on the corn kernel color ratio from Part II of the lab.
Recall from the background information that purple kernels are dominant and yellow kernels are recessive. The second ear of corn was the result of crossing two heterozygous ears of corn male purple (Pp x Pp). This is represented by the Punnett square below. Complete the Punnett Square by writing the correct letters that correspond to each number indicated in the table. (4 points)
Once the Punnett square for Question 13 is complete, calculate the ratio of purple and yellow kernels (recall that if the dominant trait is present, it will be expressed).
Recall from the background information that purple kernels are dominant and yellow kernels are recessive. Also recall that smooth kernels are dominant and wrinkled kernels are recessive. The third corn ear was the result of crossing a male ear of corn with the following gametes: PpSs, with a female ear of corn with the same gametes: PpSs. This is represented by the Punnett square, below. Complete the Punnett square by writing the correct letters that correspond to each number indicated in the table (for example, PPSS or ppss). (8 points)
Once the Punnett square for Question 15 is complete, calculate the ratio of corn kernel varieties (recall that if the dominant trait is present, it will be expressed).
What are the genotypic and phenotypic ratios for kernel color and kernel texture for a dihybrid cross between PpSS x Ppss? (4 points)
Using the results from the Punnett Square in Question 15, answer the following question: In a population of 300 corn kernels, how many will have smooth kernel texture? (2 points)
In a flower garden, a horticulturist is growing purple and white pansies. The horticulturist notices that a new pansy has sprouted. When it finally flowers, the pansy is lavender. Explain how this happened. (4 points)
With a botanist’s help, an individual decides to cross the lavender pansy with the white pansy. Will this result in any purple pansies? Explain. (4 points)
State an industrial concern/importance for knowing the genetic makeup of an organism. Explain why it is important in your example. (5 points)
What is the phenotypic ratio of offspring from a cross between Pp x pp? (2 points)
In a population with 160 individuals how many will be homozygous? (2 points)
In that same population, how many will be purple? (2 points)
Which of Mendel’s laws is illustrated in a dihybrid cross? (1 point)
What does this law mean, in your own words? (1 point)
What was the tallied frequency (phenotypic ratio) of purple to yellow kernels from Step 1? Which of the possible Mendelian ratios is best represented by this corn cob? (2 points)
What was the tallied frequency (phenotypic ratio) of purple to yellow kernels from Step 2? Which of the possible Mendelian ratios is best represented by this corn cob? (2 points)
What was the tallied frequency (phenotypic ratio) of purple and smooth, purple and wrinkled, yellow and smooth, or yellow and wrinkled kernels from Step 3? Which of the possible Mendelian ratios is best represented by this corn cob? (Remember there were four possible types for this part of the lab.) (2 points)
Explain why the tallies from each corn cob do not exactly match the Mendelian ratio. (2 points)
P
p
P
1
2
p
3
4
What is the ratio of purple to yellow kernels based on the Punnett square? (2 points)
How did this Mendelian ratio numerically compare to the ratio obtained from counting the corn kernels for ear number two in part II of the lab? (2 points)
PS
Ps
pS
ps
PS
1
2
3
4
Ps
5
6
7
8
pS
9
10
11
12
ps
13
14
15
16
What is the ratio of kernels based on the Punnett square? (2 points)
How did this Mendelian ratio numerically compare to the ratio obtained from counting the corn kernels for ear number three in part II of the lab? (2 points)
genotypic ratio
phenotypic ratio
APPLICATION QUESTION
(Application) How might the information gained from this lab pertaining to genetics be useful to you, or how can you apply this knowledge to your everyday life as a non-scientist? The
