Classwork: Comparison between Mitosis and Meiosis
Group: 405
Name: Marcela Medina
ID: A01194319
Introduction to the activity:
The cell is the basic unit of life. It can form unicellular organisms, or join with other cells to form
multicellular organisms. The maintenance and reproduction of these organisms depend on two processes of
cellular division: mitosis and meiosis.
The process of mitosis occurs in somatic or body cells. It is responsible for the production of new cells that
substitute damaged or dead cells, as well as for the production of new cells during growth and development.
For example, every minute, millions of red blood cells must be produced to replace those that die.
Meiosis is the process of cell division that is present exclusively in cells that will become gametes, cells
responsible for reproduction of the organism. The principle function of meiosis is to produce gametes that
are genetically different from each other and contain half the number of chromosomes so that during
fertilization, that offspring will have the complete number of chromosomes and will be different from the
parents. Therefore, meiosis allows genetic recombination that permits variations within the same species
and assures the evolutionary success of the species.
Materials required
Copy of the activity
Access to internet
Instruction/steps
Part 1: The cell cyle
1. Draw a diagram of the cell cycle indicating each of its stages, as well as the divisions within each
stage. Describe the major activity that occurs in each stage.
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Part II: Comparison of Mitosis and Meiosis
1.
Use your ebook to fill in the following table:
Characteristics of
comparison
Type of cell that it occurs in
Mitosis
Meiosis I
Somatic cell
Reproductive cell
Reproductive cell
Total number of cells
produced
1
2
4
Presence of genetic
variation
no
yes
yes
Type of cells produced
(haploid or diploid)
haploid
haploid
haploid
Importance of the process
Cells are
reproduces evry
day becuase of
mitosis
The result can be
mutation if
process fails
It occurs in sexual
organisms
It occurs in sexual
organisms
We don’t adapt and
sexual reproduction
does not occur
A chromosomal disease
(down syndrome)
Impact if the process fails
2.
Meiosis II
Based on the information in the above table and your eBook, answer the following questions:
a. What would happen if mitosis did not occur?
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Wll your body for straters would be a lot slower and also wouldn’t be able to reproduce
tissues.
b. What would be the consequences if meiosis did not occur?
We wouldn’t be able to adapt nor to reproduce.
c.
What would be the effects on evolution of the species if there was no genetic variation?
We would all be the same.
Part III: Define the following terms:
Apoptosis: or programmed cell death, decreases the number of cells.
The cell: Cycle is an orderly set of stages that take place between the time a cell divides and the time
the result- ing cells also divide.
Crossing over: means that the chromatids held together by a centromere are no longer identical. As a result
of crossing-over, the daughter cells receive chromosomes with recombined genetic material.
Cytokinesis: he division of the cytoplasm,
Mitosis: the division of the nucleus and genetic material,
Meiosis: reduces the chromosome number in such a way that the daughter nuclei receive only one
of each kind of chromosome. The process of meiosis ensures that the next generation of individuals will
have only the diploid number of chromosomes and a combination of traits different from that of either
parent.
Genetic recombination: process where the genes are combined to produce a new cell.
Haploid number: Half the diploid number, called the haploid (n) number of chromosomes, contains only
one of each kind of chromosome.
Diploid number: human cells contain 46 chromosomes, corn has 20 chromosomes, and the crayfish has
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200! This number is called the diploid (2n) number because it contains two (a pair) of each type of
chromosome
Homologous chromosome: two pairs of chromosomes.
Independent assortment: occurs because there are various ways for chromosomes to line up in metaphase I
of meiosis I
Interphase: The cell prepares to divide; it grows bigger, the number of organelles doubles, and the amount
of DNA doubles
Nondisjunction: is the failure of paired chromosomes or chromatids to separate during cell division.
Oogenesis: n human females, meiosis is a part of oogenesis, which occurs in the ovaries and produces
eggs
Sister chromatid: Genetically identical chromatids.
Somatic cell: any cell of a living organism other than the reproductive cells.
Spermatogenesis: In human males, meiosis is a part of spermatogenesis, which occurs in the testes and
produces sperm.
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Synapsis: During meiosis I, the homologous chromosomes come together and line up side by side.
Zygote: A haploid sperm (n) and a haploid egg (n) join at fer- tilization, and the resulting zygote has the full,
or diploid (2n), number of chromosomes.
Gamete: a mature haploid male or female germ cell that is able to unite with another of the opposite sex in
sexual reproduction to form a zygote.
Evaluation
Evaluation criteria
Contents of the report
Analysis of the
information
vocabulary
Report format
3
2
1
The report contained a
diagram of the cell
cycle, the comparative
table completed and
all the questions
answered.
All of the questions
were answered
correctly according to
the information asked
for in the comparison
table.
All 20 of the
vocabulary terms were
completed correctly.
The report contained a
diagram of the cell
cycle, the comparative
table was incomplete,
and all the questions
answered.
Some of the questions
were answered
correctly according to
the information asked
for in the comparison
table.
At least 15 of the
vocabulary terms were
completed correctly
The report contained a
diagram of the cell
cycle, the comparative
table incomplete and
not all the questions
answered.
None of the questions
were answered
correctly according to
the information asked
for in the comparison
table.
At least 10 of the
vocabulary terms were
completed correctly.
Followed teacher´s
instructions with
respect to format and
content.
Followed teacher´s
instructions with
respect to format but
not content.
Did not follow
teacher´s instructions
with respect to format
and content.
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