Cell Division
1. In your own words, define cell division. Describe the two types of cell division. What
is the purpose of each? How many and what types of cells are produced by each kind
of cell division.
2. Define in your own words the following terms (use drawings to help explain):
chromatin, chromosome, duplicated chromosome, sister chromatid, centromere,
homologous chromosomes (or homologues) Do sister chromatids carry identical
genetic information? Do homologous chromosomes?
3. Describe the relationship between autosomes (somatic chromosomes), sex
chromosomes, somatic cells and sex cells. Describe the terms diploid (2N) and
haploid (N).
4. What is the role of cytoskeleton in cell division? What are centrioles, spindle fibers,
microtubules, and how do they coordinate the various events of cell division?
5. Describe the cell cycle. Draw a simplified illustration of the cell cycle showing
interphase and mitosis. Next, label G1, S, G2 and the four phases of mitosis. What is
the longest phase of the cell cycle? Describe what happens during each phase of
interphase. Why must DNA replicate prior to mitosis and exactly when does this
occur?
6. What is the purpose of mitosis? Mitosis has four distinct stages. What are they and
describe what happens in each stage. Draw a simple diagram of what a cell nucleus
would look like in each phase.
7. What is cytokinesis and when does it occur? How is it different in animals versus plant
cells? Describe cleavage and how animal cells separate.
8. Answer the following practice problems, related to haploid vs. diploid cells:
 If a cell has 13 chromosomes as a haploid cell, how many chromosomes are found in
the diploid cell of the same organism?
 If a somatic cell has 30 chromosomes, how many are in the gametes?
 A gamete has 8 chromosomes, is this the N or 2N number? How many chromosomes
then, are in the somatic cells?
 If a somatic cell has 24 chromosomes, how many homologues are there?
 What is the haploid and diploid number of chromosomes in humans?
9. What is the purpose of meiosis in multicellular organisms such as plants and animals?
What are gonads and gametes? Meiosis is broken into two parts: meiosis I and
meiosis II. Name the stages of meiosis I and II. Describe the events of each phase.
10. What are some of the differences between meiosis in spermatogenesis vs. oogenesis?
11. What is synapsis/crossing over? What are tetrads? When does it occur? What is the
significance of crossing over? Describe how the separation of chromosomes is
different in Anaphase I vs. Anaphase II.
12. Independent assortment and random fertilization are also contributors to genetic
diversity. Explain what each of these is and how they contribute to this diversity.
13. How is the outcome of mitosis different from meiosis in cell number and
chromosome number? If a cell has 32 chromosomes and undergoes meiosis, how
many chromosomes would be found in each daughter cell? What if the original cell
undergoes mitosis?
14. What is nondisjunction and what kind of disorders can result from this problem?
What is a karyotype and why are they useful in detecting non-disjunction related
disorders?
15. What is the cause of Down’s syndrome and what is the relationship between Down’s
syndrome and the age of the mother.
16. Describe cri-du chat, fragile x syndrome Klinefelter’s and Turner’s syndrome.
17. What are mutagens? What are carcinogens?
Heredity-Mendelian Genetics:
18. Who was Gregor Mendel? What were the primary organisms he used in his research?
What are monogenetic traits? What is meant by Mendelian Inheritance?
19. List the four parts of the Law of Segregation?
20. What are genes? What are alleles? Describe the terms genotype and phenotype.
21. What is meant by homozygous and heterozygous? What is a dominant allele vs. a
recessive allele? Describe the conventions used in writing these (e.g. upper/lowercase
letters).
22. How do an organism’s genes get distributed into their gametes? What does this aspect
of inheritance have to do with the events of cell division?
23. What is the law of independent assortment and what does it have to do with the
events of cell division?
24. When doing a punnett square, what do the letters outside of the box represent and
where do they come from (be specific)? If a parent is homozygous dominant for a
trait, how many different kinds of gametes can (s)he make? Give an example If the
parent is homozygous recessive …? Example? If the parent is heterozygous ...?
Example? What do the letters inside the box represent (be specific)?
25. Show a cross using the following information: L = long wings, l = short wings Show
the punnett square and give the genotypic and phenotypic outcomes of the offspring.
26. Distinguish between complete dominance, co-dominance and incomplete dominance.
27. Human blood groups have which two types of dominance? Explain/show how this
works.
28. What is meant by multiple alleles? Give an example. If a man of blood type B and a
woman of blood type A have children, show (by punnett square) how they could have
children of all blood phenotypes (A, B, AB and O).
29. What is meant by Polygenic Inheritance? Give an example of a human trait that is
governed by polygenic inheritance.
30. What are sex-linked traits? Give some examples. Which sex is generally affected in a
greater percentage? Why? What is the meaning of the term hemizygous?
31. If a colorblind male marries a carrier female, what are the chances that their children
will be color-blind?
32. What is meant by an "autosomal recessive trait"? What is meant by an "autosomal
dominant trait"?
33. Describe the conventions used in designing pedigrees. What do circles and squares
indicate? How are “affected” individuals shown? How are adoptions, deaths,
mariages/matings and siblings shown?