1. What is an allele?
2. Give an example of a genetic trait and two alleles for the gene that determine the trait
a. Genetic trait
b. Allele #1
c. Allele #2
3. Compare and contrast the terms phenotype and genotype. --Answer below:
4. List the allele combinations (gamete possibilities) that can be formed by an individual with the following genotype: AABB (2 points)a.--Answer below:
5. List the different allele combinations (gamete possibilities) that can be formed by an individual with the following genotype: AaBb. (4 points)a.b.c.d.--Answer below:
6. Given: P = purple flowers and p = white flowers and P is dominant over p. a. What is the phenotypic ratio of offspring from a cross between Pp x pp? (2 points)b. In a population with 160 individuals how many will be homozygous? (2 points)c. In that same population, how many will be purple?--Answer below:
7. a. Which of Mendel's laws is illustrated in a dihybrid cross? ) b. What does this law state? )--Answer below
AND
Use the following information for Questions 8-11.
Let R = red flowers and r = white flowers; Red is dominant over white coloration; S = smooth seed covers and s = wrinkled seed covers; Smooth is dominant over wrinkled.
RS RS rS rS
Rs 1 2 3 4
Rs 5 6 7 8
rs 9 10 11 12
rs 13 14 15 16
8. Complete the Punnett square referenced above for the dihybrid cross by entering the genotypes below.
9. What are the genotypic and phenotypic ratios for color and seed cover for a dihybrid cross between RrSS x Rrss? a. genotypic ratiob. phenotypic ratio--Answer below:
10. What is the probability of this cross resulting in a plant that is red with wrinkled seed covers? (--Answer below:
11. In a population of 100, how many will have smooth seed covers?--Answer below:
12. The student has a purple plant and a white plant. The student 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? Answer below:
13. The student runs a test cross with an offspring purple plant from Question 12. The phenotypic frequencies of the resulting offspring are 50% white and 50% purple. What is the true genotype of this offspring purple plant? --Answer below:
14. Using Mendel's laws, explain why 0% of the offspring from a cross between a homozygous purple pea plant (e.g. PP) and a homozygous white pea plant (e.g. pp) are white, while 25% of the offspring from a cross between two heterozygous purple pea plants (e.g. Pp x Pp) are white. --Answer below:
15. Compare the 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. )--Answer below:
16. The student's father is very tall. The student's mother is very short. The student's height is somewhere in between. Is this codominance or incomplete dominance? Justify your answer. --Answer below:
17. If a person were to have 14 children in a row, all female, what is the probability the next child would be a female? --Answer below:
18. In the sickle cell activity, what happened to the percentage of surviving alleles that were HbA and the percentage of surviving alleles that were HbS over the course of the experiment? Why did this happen? (5 points)--Answer below:
19. Will these percentages continue to change as they did in the first few generations? Why or why not? --Answer below
20. Explain the impact of malaria of the HbS allele in Africa vs. the United States.
21. (Application) How might the information gained from this lab pertaining to genetics be useful to the student or how can the student apply this knowledge to everyday life as a non-scientist? -Answer below:.