Assignment

CHAPTER 12: THE CELL CYCLE

1.Define genome:

2. What is the difference between DNA in the chromatin form and the chromosome form? What form is DNA in during most of the cell cycle?

3. What is the difference between the centromere and the kinetochore?

4. What happens during each of these phases of the cell cycle?

G1:

S:

G2:

M:

5. The mitotic spindle is mainly made of what type of protein fiber?

6. How does cytokinesis differ between plant and animal cells?

7. Is binary fission truly mitosis? What type of organisms use binary fission for reproduction? Is this process sexual or asexual?

8. Draw/depict the phases of mitosis from prophase to the end of cytokinesis for an animal cell containing a total of six chromosomes.

9. What is the cell cycle control system and why is it important?

10. What happens to most mammal cells when they reach the G1 checkpoint?

11. Explain howMPF helps to regulate the cell cycle. (See Fig 12.16)

12. What is a growth factor? Provide an example from the chapter.

13. What does cancer have to do with the cell cycle?

14. Explain why each of the following would undergo mitosis:

An early embryo:

An amoeba:

Skin cells:

A broken bone:

15. How is prokaryotic DNA different from eukaryotic DNA?

16. Are the daughter cells produced by mitosis clones of the parent cell?

17. When mitosis is used for reproduction, is it sexual or asexual? What type(s) of organisms use mitosis for reproduction?

CHAPTER 13: MEIOSIS & SEXUAL LIFE CYCLES

1.Define:

Gene

Allele

Locus

Gametes

Somatic cells

2. What is the difference between sexual and asexual reproduction (in terms of number of parents, and variation in offspring)?

3. What is the difference between homologous chromosomes and sister chromatids? (Where do they "come from"? Are they identical?)

4. What are autosomes? How many pairs of autosomes do humans have?

5. Meiosis produces gametes.

What are gametes used for?

What is the union of gametes called?

The union of gametes creates what?

6. What is the difference between cells that are haploid and cells that are diploid?

Are gametes haploid or diploid?

Are somatic cells haploid or diploid?

7. Do the following eukaryotes primarily reproduce sexually or asexually?

Animals:

Plants:

Fungi:

8. How many daughter cells does meiosis produce?

Are they diploid or haploid?

Are they clones of the parent cell?

9. Draw/depict Meiosis Prophase I and Metaphase I for three pairs of chromosomes:

10. What happens during synapsis? Does synapsis happen during mitosis?

11. What are three things that happen during meiosis but not mitosis? (See P.260)

12. What is independent assortment of chromosomes? During which phase of meiosis does this occur?

13. If a cell undergoing meiosis has a haploid number of 6, what is the number of different combinations of chromosomes that can occur in the daughter cells?

14. Explain what crossing over is and how it increases genetic variation in sexually reproducing organisms.

15. How is genetic variation introduced into asexually reproducing organisms like bacteria?

16. Why do most eukaryotes reproduce sexually? (What is the advantage?)

CHAPTER 14: MENDEL & THE GENE IDEA

1. What is the difference between a character and a trait?

2. What is the difference between an individual's genotype and phenotype?

3. What do we know about the genotype of true-breeding plants in Mendel's experiments?

4. In Mendel's experiments, what is the genotype of the individuals in a monohybrid cross (F1 x F1)? What is their phenotype?

5. Are dominant alleles always more common than recessive alleles in a population?

6. What is the law of segregation? This occurs during which phase of meiosis?

7. In complete dominance, do homozygous dominant individuals have the same phenotype as heterozygous individuals? Do they have the same genotype?

8. Mrs. Smith has a widow's peak (her genotype is Ww), but her husband does not (his genotype is ww).

What are the possible gametes for Mrs. Smith ___________ Mr. Smith _____________

Make a Punnett Square for potential offspring produced by this couple:

What is the probability that their child will have a widow's peak?

What is the probability that they will have two children both with widow's peaks?

9. Mendel's dihybrid cross (F1 x F1) looked at the inheritance of two characters. What were the genotypes of the F1 plants?

Did he find that seed color and seed texture were inherited together or independently? Explain.

10. Besides having a widow's peak (Ww), Mrs. Smithalso has attached earlobes (ff). Mr. Smith does not have a widow's peak (ww) or attached earlobes (Ff).

Considering both of these characters together, what are the possible gametes

for Mrs. Smith _________________________ and Mr. Smith __________________________?

Make a Punnett Square for both of these characters together.

What is the probability that their child will have a widow's peak and attached earlobes?

What is the probability that their child will have no widow's peak NOR attached earlobes?

11. An individual has a genotype WwFf. What are the possible gametes that this person can make in respect to these two genes?

12. In incomplete dominance, do homozygous dominant individuals have the same phenotype as heterozygous individuals?

13. How is codominance different from incomplete dominance?

14. Do most genes only have two alleles?

15. Explain:

Pleiotropy

Epistasis

Polygenic inheritance

16. Give an example of how environment can affect an organism's phenotype?

17. In a recessively-inherited disorder, what are the genotypes of:

A normal person

A carrier

An afflicted person

18. Why are dominantly-inherited disorders less common than recessively-inherited disorders?

19. Duncan and Maria are both carriers of cystic fibrosis, a recessively-inherited disorder. Draw a Punnett square to show their possible offspring.

What is the probability that their child will have cystic fibrosis?

CHAPTER 15: CHROMOSOMAL BASIS OF INHERITANCE

1. According to Morgan's terminology, what is the difference between wild type and mutant phenotype?

2. Look at Figure 15.4. How did Morgan figure out that the gene for eye color is on the X chromosome? Explain the F1 cross and what was produced in F2.

3. What are sex-linked genes?

4. In mammals (and fruit flies) are males or females the heterogametic sex? Is this the case for all species?

5. Draw a Punnett square to show how sex is determined in humans (XX x XY). This also explains why we have about a 50:50 sex ratio.

6. Which chromosome carries more genes, X or Y?

Are there genes on the Y chromosome that are important for all humans? What type of genes are found on the Y chromosome?

7. Why are men more likely than women to get a sex-linked disorder?

8. Can a man pass on a sex-linked disorder to his sons? Explain.

9. Define:

Non-disjunction

When can non-disjunction occur?

Aneuploidy

10. When aneuploidy occurs, what usually happens to the embryo?

11. Explain what happens to the DNA when the following occur:

Deletion

Duplication

Inversion

Translocation

12. What causes Down syndrome?