Download Genetics Review Online

Genetics Review Online
Name_______________________________________
Go to: http://www.dnaftb.org/dnaftb/1/concept/index.html
-Click on “Bio” at the bottom and fill in the missing Mendelian law.
1. The Law of ___________________: Genes for different traits are sorted
separately from one another so that the inheritance of one trait is not
dependent on the inheritance of another.
2. The Law of __________________: An organism with alternate forms of a
gene will express the form that is dominant.
3. The Law of ______________: Each inherited trait is defined by a gene pair. Parental genes are
randomly separated to the sex cells so that sex cells contain only one gene of the pair. Offspring
therefore inherit one genetic allele from each parent when sex cells unite in fertilization.
-Click Genes Come in Pairs. Click on Problem.
4. To get a pure-bred colored plant, you start with a colored flower plant. What should you do next?
5. To get a pure-bred colored flower plant, you let a colored flower plant self-fertilize, then you plant,
and grow the seeds. Most of the plants you get have colored plants, but a few have white flowers.
What should you do next?
6. To get a pure-bred colored, you choose several colored flower plants, and let them self-fertilize,
then you plant and grow the seeds. Many of the self-fertilized plants have some colored and white
flowers. You choose one of the plants from a family with all colored flowers, let it self-fertilize, then
you plant and grow its seeds. All the plants you get have colored flowers. Now what?
-Click on Genes don’t blend. Click on Problem.
7. If you cross a pure-bred colored flower with a pure-bred white flower, what will the F1’s
phenotype(s) be?
8. What if you cross-fertilize the white flower with pollen from the colored flower?
-Click on Some genes are dominant. Click on Animation.
9. Review the animation…then answer: If bushy eyebrows is
dominant over “non-bushy” eyebrows, then why haven’t all
people become bushy eyebrowed?
-Click on Genetic inheritance follows rules. Click on Problem.
10. If there is a tall and yellow pea plant heterozygous for these two traits (height and seed color),
what are the dominant phenotypes?
11. If we are tracking two traits (instead of one), we are doing a _______________cross.
12. What is the genotype of this tall, yellow plant (if it is heterozygous for both traits)?
13. What is the genotype of a short, green plant?
14. What types of gametes will a TtYy plant produce?
15. How does a Punnett square differ in a dihybrid cross (when compared to a monohybrid cross)?
16. How many plants are tall and yellow? ____________ How many plants are short and yellow?
____________ Tall and green? ___________ Short and green? ____________
17. What is the ratio if you cross 2 parents that are heterozygous for two traits (in a dihybrid cross)?
18. Are tall plants always yellow? (no / yes) Are short plants always green? (no / yes)
19. The inheritance of one gene does not depend on the inheritance of another. This is Mendel’s Law
of __________________________.
-Click on Bio.
20. Who devised the “Punnett square”
-Click on Genes are real things. Click on Gallery
21. Read the red highlighted excerpt from the 1906 letter to the American Breeders Association. What
was Mr. Spillman trying to say in this “red” portion of his letter?
-Click on All cells arise from pre-existing cells. Click on Problem.
22. The body (somatic) cells of fruit flies have ___________(#) chromosomes.
23. Body cells undergo mitosis. How many sister chromatids does each cell
have during metaphase? _________By the end of mitosis, how many
chromosomes in each cell? _________
-Click on Specialized chromosomes determine gender. Click on Animation
24. Summarize what Nettie Stevens contribution to the genetics world was? How did she make this
contribution?
25. At the end of the animation, read the “Did you know?” What happens if, during meiosis, one
sperm receives no sex chromosomes whereas another sperm receives 2 sex chromosomes?
-Click on Chromosomes carry genes. Click on Animation.
26. The white-eyed trait in fruit flies appeared in a 3:1 ratio in the F2 generation. However the
(males / females) were the only one with white eyes. This suggested that the white-eyed trait is
carried on the X chromosome.
27. Look at the Punnett square for the F1 generation (on the next page). The “w” stands for recessive
white. The “R” stands for dominant red. How many female offspring? _______How many male
offspring? ______ How many white eyed females? _______ How many white eyed males? _________
28. Look at the Punnett square for the F2 generation. How did the results differ?
29. Describe 3 of the mutant flies that were studied:
a.
b.
c.
-Click on Mendelian laws apply to human beings. Read the concept. Then click on Problem. Read through the
examples and learn about pedigrees as you go.
30. John has alkaptonuria; it “runs in the family”. Although his father, paternal uncles and aunt do not have it,
his paternal grandmother did. What is one thing you learned about pedigrees?
31. What is a “consanguineous relationship”? How are they represented in pedigree charts?
32. If John marries someone who is heterozygous for alkaptonuria, what are the possible phenotypes for their
offspring?
33. Demonstrate this (#32) with a Punnett square?
-Click on Mendelian genetics cannot fully explain…
34. The eugenics movement embraced Mendel’s ideas. What is eugenics?
35. What did eugenists do wrong?
Go to: http://highered.mcgraw-hill.com/sites/0072485949/student_view0/chapter3/interactive_activity.html
Read the description thoroughly before completing Exercise 1.
36. Reading a pedigree: In pedigrees, males are indicated by a ____________, and a female by a _____________.
A horizontal line between male & female indicates a ____________ and a vertical line indicates descent (i.e.,
_______________). Individuals with the trait studied are indicated by blackened symbols.
37. From pedigree 1 below, how many children do A and B have? _________How many grandkids? _________
38. What are the genotypes of A?____________ B?____________ C?______________ D?____________
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Click on Exercise 2 and answer the following from Pedigree 2 below:
39. What are the genotypes of A? __________ B? ____________
40. What are the genotypes of A’s parents? Dad ______________ Mom _____________
41. What are the genotype frequencies of D (and her mate’s) offspring? Please answer in terms of percentages.
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