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Eastern Regional High School
Honors Biology
Name: ANSWER KEY
Mod:__________ Date:__________________
Unit 11 – Cell Division – The Cell Cycle, Mitosis, and Cancer
Review Packet
1. Explain the process of binary fission in prokaryotic cells.
1
2
3
4
Replication of the plasmid DNA inside the cell.
Replicated DNA move to either poles of the cell.
The cell elongates.
The equatorial plate of the cell constricts and separates the plasma
membrane (cytokinesis) so each new cell has exactly the same genetic
material.
2. How are eukaryotic chromosomes different from prokaryotic chromosomes?
Eukaryotic Cells have multiple chromosomes (Humans have 46) and
when they are duplicated and condenses they have the familiar “x”
shape pattern.
Prokaryotic cells have one circular piece of DNA known as a plasmid.
3. Describe the difference between sexual and asexual reproduction.
Asexual Reproduction involved only ONE parent – binary fission and
mitosis are asexual forms of cellular reproduction
Sexual Reproduction involves the combination of genetic material
from two parents (sperm and egg cells)
4. Explain the relationship between DNA, histone proteins, chromatin and chromosomes.
DNA is wrapped around protein molecules known as histones. Uncoiled
DNA is known as chromatin. Condensed, visible, DNA are known as
chromosomes
5. What type of reproduction is mitosis? Asexual
6. Describe the events in the cell cycle.
G1 – Growth phase – cell
copies organelles,
increases ATP levels,
increases in volume
M Phase – Cell
Division: Mitosis
and Cytokinesis
S Phase – DNA is
copied in preparation
for cell division
G2 – growth in preparation for division –
increased ATP levels, more proteins are produced
for cell division
7. List the 3 stages in interphase and describe what happens in each phase.
Redundant Question SORRY!
See answer to previous question
8. In which phase of the cell cycle do cells spend the most time? Interphase
9. When during the cell cycle is DNA in the form of chromatin? Interphase
10. When during the cell cycle is DNA in the form of chromosomes? Mitosis (PMAT)
11. Label the structure of a duplicated chromosome below:
Chromosome
Telomeres
Centromere
Telomeres
Each half is called a sister chromatid
12. List and describe the phases of mitosis:
Prophase
Chromosomes begin to coil and become distinguishable thin, threadlike structures, widely dispersed in
the nucleus during prophase. Although there are no centrioles in plant cells, a spindle begins to form.
Nucleoli begin to disappear. The nuclear envelope is still intact.
Metaphase
Metaphase begins when the centromeres of the chromosomes lie on the equator of the cell. The arms
of the chromatids extend randomly in all directions. A spindle may be apparent. Spindle fibers are
attached to centromeres and extend to the poles of the cell. As metaphase ends and anaphase begins,
the centromeres split.
Anaphase
The splitting of centromeres marks the beginning of anaphase. Each former chromatid is now a
chromosome. Single-stranded chromosomes are drawn apart toward opposite poles of the cell.
Anaphase ends when the migrating chromosomes reach their respective poles.
Telophase
Chromosomes have now reached the poles. The nuclear envelope reforms around each compact mass
of chromosomes. Nucleoli reappear. Chromosomes begin to uncoil and become indistinct.
13. Describe the number of chromosomes found in both parent and daughter cells produced
by mitosis. (Use 46 as your sample chromosome number)
They should be the same in the daughter cells – 46 chromosomes for
humans
14. List a feature of plant cell division that distinguishes it from animal cell division.
Formation of cell plate during cytokinesis
No centrioles
15. List a feature of animal cell division that distinguishes it from plant cell division.
Formation of cleavage furrow during cytokinesis
Centrioles are present
Animal Cell
Plant Cell
16. List two types of cells that do NOT divide. Pancreatic cells, Neurons
17. List 3 functions of mitosis.
1.
2.
3.
4.
5.
6.
Growth – Makes more Somatic (Body) Cells
Development from Embryo
Repair Damaged Tissue – Somatic Cells
Replace worn out somatic cells
Reproduction – Asexual (Binary Fission v. Mitosis)
Response to Stimuli – ex. Plants grow toward light
18. Describe the two types of cancer.
Malignant Tumors – Spread throughout the body via the circulatory or
lymphatic systems
Benign Tumors – Stay in one location
19. Describe the three types of cancer treatment and their associated problems.
Surgery – removes mass of cancer cells – must take surrounding
healthy cells in the process – dangerous to health of individual
Radiation – cancers cells are killed via exposure to harmful radiation
waves (x-rays or gamma rays) – shotgun approach to treatment that
damages all the surrounding healthy tissue.
Chemotherapy – toxin is used to target and kill rapidly dividing cells –
also kills healthy cells that divide rapidly, skin, hair, bone marrow,
stomach cells
20. Why do cells divide? Smaller is better – avoids DNA overload and transport
issues
21. Explain why smaller cells are “better” cells.
Surface Area v. Volume – Large Ratio is Better - volume of the cell increases more
rapidly then the surface area of its membrane. Creates transport problems and DNA
overload issues.