Section 11-1: the Work of Gregor Mendel
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Chapter 11: Introduction to Genetics
Section 11-1: The Work of Gregor Mendel 1. Define genetics.
2. Discuss why Gregor Mendel used peas as his model organisms for his genetic studies.
3. What does it mean to be a fertilization ?
4. How did Mendel control the self-pollination of the pea plants?
5. A trait is a:
6. What is a hybrid?
7. What is the P generation______The F1 generation______
8. What happened each time Mendel cross plants pure for contrasting traits?
9. Define what a gene is.
10. An allele is: 11. Mendel’s two conclusions as a result of his experiments were: 1.
2.
12. When will the recessive trait be observed in an individual?
13. What happened when Mendel crossed 2 offspring from his F1 looking at figure 11-4
14. Looking at figure 11-5 and the reading, explain what segregation is.
Section 11-2: Applying Mendel’s Principles 15. How does probability come into play in the study of genetics?
16. What does it mean to be homozygous for a trait? Heterozygous?
17. Define phenotype and genotype.
18. What is a Punnett square?
19. In pea plants, tall stem is dominant over short stems. If T = Tall stems and t = short stems, use a Punnett square to show the F1 cross from#14 (look at figure 11-8) 20. What does the above Punnett square show about the possible gametes formed as a result of this cross?
21. What are the two possible phenotypes for the Punnett square shown in #19?
22. What is the probability (out of 4) of getting a tall plant from the cross in #19?
23. What are the 3 possible genotypes for the cross in #19?
25. Out of 4, how many could be each of the 3 genotypes?
______TT: ______Tt : ______tt
26. For the tall and short stem traits, using the same symbols, what would a: a. homozygous dominant genotype look like? ______b. Homozygous recessive genotype ______c. Heterozygous genotype ______d. What is another term for heterozygous? ______
27. Let’s try some problems: If a plant is pure for green pea pods (GG) is crossed with another plant, hybrid for green pea pods (Gg): a. Construct a Punnett square to show the cross.
b. Figure out the Phenotype ratio (how many will be green to how many will be yellow)
c. Figure out the Genotype ratio (how many GG, Gg or gg can occur)
28. Do another problem but this time, cross a heterozygous (Gg) green with a homozygous recessive (gg) plant. a. Punnett square of the cross:
b. Phenotype ratio c. Genotype ratio
29. Did Mendel find that the gene that determines seed shape has anything to do with how seed color is inherited?
30. Let R = Round seeds, r = wrinkled seeds Y = Yellow seeds, y = green seeds What would a homozygous round, yellow seed genotype look like? ______What would a homozygous wrinkled, green seed genotype look like? ______
31. As a result of a cross between the above plants, what would the F1 genotype be? (figure 11-9).
32. What kind of cross did you just do? ______cross.
33. FOIL RrYy and get the 4 possible gene combinations that may result from meiosis.
34. Do an F1 cross of 2 offspring from #31. (figure 11-10)
34. What is the probability of getting the 4 different phenotypes?
35. Explain Mendel’s law of Independent assortment.