Name:
Biology
Cell Reproduction
Review Packet
Define the following terms:
Chromatid: one of the two identical copies of DNA making up a duplicated
chromosome
Chromosome:single piece of coiled DNA
Homologous Chromosome:matching pairs of chromosomes
Tetrad:two homologous chromosomes formed during meiosis (prophase 1)
Gamete:sex cell
Somatic Cell:body cell
Crossing over:during prophase 1 when gene segments are exchanged
Synapsis:joining together of homologous chromosomes to form a tetrad
Disjunction:during anaphase when the tetrad is pulled apart into 2 equal parts
1. In a human, what is the ratio of the normal chromosome number in a nucleus
produced by mitosis to the normal chromosome number in a nucleus produced by
meiosis?
a. 1:1
b. 2:1
c. 3:1
d. 4:1
2. The distribution of chromosomes in one type of cell division is shown in the diagram
below.
Which process is represented in the diagram?
a. asexual reproduction
b. meiosis
c. mitosis
d. vegetative propagation
3. Which statement best explains the observation that clones produced from the same
organism may not be identical?
a. Events in meiosis result in variation.
b. Gene expression can be influenced by the environment.
c. Differentiated cells have different genes.
d. Half the genetic information in offspring comes from each parent.
4. Which event normally occurs in meiosis but not in mitosis?
a. chromosome replication
b. synapsis of homologous chromosomes
c. nuclear membrane disintegration
d. movement of chromosomes to opposite poles
5. In the process of oogenesis in humans, a primary sex cell undergoes divisions that
normally produce
a. 4 sperm
b. 1 sperm and 3 eggs
c. 1 egg and 3 polar bodies
d. 4 eggs
Base your answers to questions 6-9 on the diagram below and your knowledge of
biology. The diagram represents a single-celled organism, such as an amoeba,
undergoing the changes shown.
6. As a result of these processes, the single-celled organism accomplishes
a. gamete production
b. energy production
c. sexual reproduction
d. asexual reproduction
7. Process 1 is known as
a. replication
b. meiosis
c. differentiation
d. digestion
8. Process 1 and process 2 are directly involved in
a. meiotic cell division
b. mitotic cell division
c. fertilization
d. recombination
9. The genetic content of C is usually identical to the genetic content of
a. B but not D
b. Both B and D
c. D but not A
d. Both A and D
10. Which cell process occurs only in organisms that reproduce sexually?
a. mutation
b. replication
c. meiosis
d. mitosis
11. Which statement is both true of mitosis and meiosis?
a. Both are involved in asexual reproduction.
b. Both only occur in reproductive cells.
c. The number of chromosomes is reduced by half.
d. DNA replication occurs before the division of the nucleus.
12. State the important end result of meiosis and how these cells differ from the end
result of mitosis.
Meiosis produces four daughter cells with half the DNA from the original parent
Mitosis produces two genetically identical daughter cells with the same amount of DNA
as the parents.
13. Give the meaning of crossing over, state when it occurs, and how it could affect
variation in organisms.
Crossing over is the exchange of gene segments during Prophase 1 in meiosis. This
causes variation because DNA is being rearranged and then split.
14. Distinguish between asexual and sexual reproduction.
Asexual – 1 parent, identical cell is produced
Sexual – 2 parents, variation results
15. State the differences between an egg cell and a sperm cell. (Include: where
produced, name of the process, size comparison, # produced, male/female gamete)
Egg – ovaries, oogenesis, large, 1 egg & 3 nonfunctional polar bodies, female gamete
Sperm – testes, spermatogenesis, small, 4 motile sperm, male gamete
16. List the phases of meiosis I and meiosis II and describe the events characteristic of
each.
Meiosis I
Prophase – chromosomes visible (double
set), centrioles to poles, synapsis &
crossing over occur
Metaphase – tetrads lined up on equator
Anaphase – tetrads pulled apart into
homologous chromosomes
Telophase – 2 daughter cells result (1 full
set of chromosomes)
Meiosis II
Prophase – chromosomes visible (1 full
set)
Metaphase – homologous chromosomes
line up on equator
Anaphase – homologous chromosomes
pulled apart
Telophase – 4 daughter cells result (half
original DNA)