Download CHAPTER 22: THE CELL CYCLE (MITOSIS) AND MEIOSIS

Cell Division (MITOSIS) Ch 5 and MEIOSIS (Ch 6.1-6.2)
STUDY GUIDE
Name: ____________________________
Date: _____________
1. Name the 2 types of cell division and state the differences.
Mitosis – creates 2 identical cells to the parent. Produces body cells
Meiosis – creates 4 genetically different cells. Produces sex cells (sperm & egg)
2. What is the difference between the cell cycle and cell division?
The cell cycle is a series of events that a cell goes through in order to divide. It includes
interphase, mitosis and cytokinesis.
Cell division includes mitosis (PMAT) and cytokinesis. It is the steps a cell goes through
while dividing.
3. Describe the purpose of mitosis and list the 2 reasons for mitosis?
Mitosis purpose is to create body cells that are identical to the parent cell. It takes place
in order to replace damaged and worn out cells.
4. What are the 4 main parts of the cell that are involved in mitosis?
Centrioles
Spindle fibers
Nucleus/nuclear membrane
DNA
5. Explain the difference between a chromatid, sister chromatids, chromosomes,
duplicated chromosomes and chromatin?
Word
Chromatin
Definition
A ball of tightly coiled
DNA found inside the
nucleus.
Phases
Interphase
Sister Chromatids
Also known as duplicated
chromosomes. Visible in
the form of an X.
Prophase
Metaphase
Draw Picture
Duplicated
Chromosome
Also known as sister
chromatids. Visible in the
form of an X.
Prophase
Metaphase
Chromatid
A single chromosome.
Anaphase
Telophase
Chromosome
A single chromatid.
Anaphase
Telophase
6. Draw and label a duplicated chromosome. Circle a chromatid and label the
centromere.
7. Define interphase, list the three sub stages of interphase in order and explain what
happens in each sub stage of interphase?
Interphase is a long period of cell growth; cell spends 90% of its time in interphase.
Sub phases:
G1 – The cell grows in size and starts forming organelles.
S – Also known as synthesis, DNA is replicated.
G2 – Cell finishes cell growth and prepares for cell division.
8. List the 4 phases of Mitosis in order and describe how the nuclear membrane and
DNA appear in each phase?
Phase of Mitosis
Nuclear Membrane
DNA
Prophase
Starts to disappear.
In the form of visible
duplicated chromosomes.
Metaphase
Gone
Anaphase
Gone
Telophase
Starts reappearing
Duplicated chromosomes
are lined up along the
middle of the cell.
Sister chromatids are
separated from each
other and start moving to
opposite poles.
Sister chromatids are on
complete opposite sides of
the cell.
9. Draw a picture of each phase of mitosis.
10. Label each phase in question #9. Already done above.
11. Explain the process of Cytokinesis. What does the prefix “cyto” and “kinesis” stand
for?
Cytokinesis is the splitting or separating of the cells cytoplasm.
Cyto = cell
Kinesis = split
12. What are the 2 main differences of mitosis between animal and plant cells?
Mitosis in an animal cell will have centrioles and the cell membrane will pink.
Mitosis in a plant cell will not have centrioles and since the cell membrane cannot pinch it
forms a cell plate to help separate the cell wall.
13. How many chromosomes are in one of your body cells? How many pairs would that
make?
There are 46 chromosomes total.
This would make 23 pairs. One set (23 from mom) and one set (23 from dad)
14. Explain how cancer and aging change the rate of mitosis?
If mitosis goes faster cancer can result.
If mitosis goes slower aging results.
15. Name 3 possible causes of cancer.
Chemicals, radiation and some viruses.
16. What is the cluster of cancerous cells called? What do the following words meanbenign, malignant, metastasize?
A cluster of cells is known as a tumor.
Benign = not cancerous
Malignant = cancerous
Metastasize = spreading
17. Describe at least five differences between mitosis and meiosis.
Mitosis
 For growth and to replace
old, worn out cells.
 Occurs in body cells
 Two cells from 1 cell
 Identical cells to the
parent cell.
 Same number of
chromosomes as the
original (2N) - diploid
 One division of the
nucleus.
Meiosis
•
•
•
•
•
•
To make sperm and eggs
with
Occurs in sex cells
Four cells from 1 cell
Genetically different from
the parent cell.
Half the number of
chromosomes (1N) haploid
Two divisions of the
nucleus.
18. Explain the purpose of meiosis?
Meiosis is to create 4 genetically different cells known as sex cells (sperm or egg)
19. What are sex cells?
Also known as gametes or sperm and egg.
20. Define fertilization?
Fertilization is the joining together of sperm and egg to create a fertilized egg known as a
zygote. Purpose is to create offspring.
21. What are Polar bodies?
Created during oogenesis (creation of eggs) 3 small polar bodies are produced which
will die.
(THIS IS DUE TO AN UNEVEN DIVISION OF CYTOPLASM DURING MEIOSIS)
22. What are Gametes?
Also known as sex cells or sperm and egg.
23. Define a Zygote.
A fertilized egg resulting when a sperm cell fertilizes an egg cell.
24. Why are there 4 sperm cells from the original male cell and only 1 egg cell from the
original female cell?
During spermatogenesis 1 cell divides into 4 individual sperm that are genetically
different from the parent cell. During oogenesis 1 cell divides into 4 genetically
different cells. Of these 4 cells 3 will have developed into small polar bodies which will
die and only 1 large egg will result.
(THIS IS DUE TO AN UNEVEN DIVISION OF CYTOPLASM DURING MEIOSIS)
25. What happens to the 3 polar bodies at the end of meiosis of a female cell?
They will die.
26. When meiosis is complete, how many of the original chromosomes are in the final
cells?
Always half the number of chromosomes from the original number. This is because
the cell divides two times.
27. When meiosis is complete, how many final cells are present?
4 genetically different cells.
28. Why does each sex cell have only ½ of the chromosomes, and what happens to the
number of chromosomes when the egg cell is fertilized by the sperm cell?
The cell divides two times therefore cutting the original chromosome number in half.
When the egg is fertilized by a sperm the chromosome doubles and returns to the original
number.
29. If an organism has 40 chromosomes, how many chromosomes are in each cell at the
end of meiosis? 20 (HALF THE NUMBER) At the end of mitosis? 40 (ORIGINAL #)
REFER TO YOUR PN 5.1 WORKSHEET FROM CLASSWORK FOR THE ANSWERS.
REFER TO YOUR MITOSIS REVIEW WORKSHEET FORM HW FOR THE ANSWERS.