1. An oak tree cell with 14 chromosomes undergoes mitosis.
- How many daughter cells are formed, and what is the chromosome number in each cell?
- If the same cell had undergone meiosis, how many cells would have resulted, and what would have been the chromosome number in each?
2. Humans have 46 chromosomes in each somatic cell.
- How many chromosomes does a child receive from its father?
- How many autosomes and how many sex chromosomes are present in each somatic cell?
- How many chromosomes are present in a human ovum?
- How many sex chromosomes are present in a human ovum?
3. Somatic cells of chimpanzees contain 48 chromosomes. How many chromatids and chromosomes are present at:
- Anaphase of mitosis
- Anaphase I of meiosis
- Anaphase II of meiosis
- Prophase of meiosis I
- A chimpanzee sperm.
4. In cats, a sex-linked pair of alleles determines coat color. The allele B results in orange fur, and b results in black fur.
a. You and a friend are walking down the street and see a calico cat. You tell your friend the cat is female. Your friend doubts your statement, how do you convince him?
b. An orange male is crossed with a calico female. If the female has a litter of 6 males, what are the possible phenotypes?
c. An orange female cat has a litter of 2 calico, and 1orange. What is the probable sex of the orange kitten?
d. A calico female has a litter of 7kittens; 2 orange females, 2 calico females, 1 black male and 2 orange males. What was the probable genotype of the father?
5. In humans, normal color vision vs. color blindness is determined by alleles C (normal) and c (color-blind) at an X-linked locus.
a. Can a normal daughter have a color-blind father? A color-blind mother? Explain
b. Can a normal son have a color-blind father? A color-blind mother? Explain
c. Can two normal parents have a color-blind son? A color-blind daughter? Explain.
d. A brother and sister are both color-blind. Is it possible for them to have a normal brother?. A normal sister? One parent who is normal? Explain.
6. In humans, red-green color blindness is inherited as an X-linked recessive trait. A woman with normal vision, whose father was color-blind, marries a man with normal vision, whose father was also color-blind. This couple has a color-blind daughter with a normal complement of chromosomes. Is infidelity suspected? Diagram the pedigree and explain your answer.
7. Among 160 progeny in the F2 generation of a dihybrid cross, a geneticist observes four distinct phenotypes in the ratio 91: 21: 37: 11. She believes this result may be consistent with a ratio of 9:3:3:1. Perform a Chi Square test to determine if her hypothesis is correct.
8. There is also a discussion component to this section. Please log into the discussion board and answer one of the two questions listed for Feb. 11th. Upon doing so then please RESPOND to the discussion of another student for the question you did not originally answer. So you should be on the board AT LEAST twice and under each question ONCE. If you need further guidelines for the discussion please see your syllabus, if you're still unclear then please e-mail me.