Classwork: Comparison between Mitosis and Meiosis
Group: 405
Name: Ana Sofia Lozano
ID: A01194526
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 cycle
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.
1 Part II: Comparison of Mitosis and Meiosis
1.
2.
Use your ebook to fill in the following table:
Characteristics of
comparison
Type of cell that it occurs
in
Mitosis
Meiosis I
Meiosis II
Somatic
Sexual
Sexual
Total number of cells
produced
2
2
4
Presence of genetic
variation
No
Yes
Yes
Type of cells produced
(haploid or diploid)
Diploid
Haploid
Haploid
Importance of the
process
To have new
cells, generation
of new tissues.
Genetic Variation
Genetic Variation
Impact if the process fails
Cancer
Down Syndrome,
chromosomal
diseases
Down Syndrome,
chromosomal
diseases
Based on the information in the above table and your eBook, answer the following
questions:
a. What would happen if mitosis did not occur?
• Cells will not reproduce and we would get old
b.
What would be the consequences if meiosis did not occur?
• We wouldn’t be able to adapt or reproduce
c.
What would be the effects on evolution of the species if there was no genetic variation?
• We couldn’t be able to adapt
Part III: Define the following terms:
a. Apoptosis: the death cells that occurs as a normal and controlled part of an organism’s
growth or development.
2 b. Cell cycle:
c.
Crossing over: the exchange of genes between homologous chromosomes, resulting in
a mixture of parental characteristics in offspring.
d. Cytokinesis: the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing
about the separation into two daughter cells.
e. Mitosis: a type of cell division that results in two daughter cells each having the same
number and kind of chromosomes as the parent nucleus, typical of ordinary tissue
growth.
f.
Meiosis: a type of cell division that results in four daughter cells each with half the
number of chromosomes of the parent cell, as in the production of gametes and plant
spores.
g. Genetic recombination: is the process by which two DNA molecules exchange genetic
information, resulting in the production of a new combination of alleles.
h. Haploid number: having the same numbers of sets of chromosomes as a germ cell, or
half the diploid number of a somatic cell.
i.
Diploid number: the number of chromosomes present in the body cells of a diploid
organism.
j.
Homologous chromosome: are chromosomes of the same size and similar structure.
k.
Independent assortment: formation of random combinations of chromosomes n meiosis
and in genes on different pairs of homologous chromosomes by the passage according
to the laws of probability of one of each diploid pair of homologous chromosomes into
each gamete independently of each pair.
l.
m. Interphase: the resting phase between successive mitotic divisions of a cell, or between
the first and second divisions of meiosis.
n.
Nondisjunction: the failure of one or more pairs of homologous chromosomes or sister
chromatids to separate normally during nuclear division, usually resulting in an
abnormal distribution of chromosomes in the daughter nuclei.
o. Oogenesis: the production or development of an ovum.
3 p. Sister chromatid
q. Somatic cell: any cell of a living organism other than the reproductive cells.
r.
Spermatogenesis: the production or development of mature spermatozoa.
s.
Synapsis: the fusion of chromosome pairs at the start of meiosis.
t.
Zygote: a diploid cell resulting from the fusion of two haploid gametes.
u. 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
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.
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.
Did not follow
teacher´s
instructions with
respect to format
and content.
vocabulary
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
Report format
Followed teacher´s
instructions with
respect to format
and content.
Followed teacher´s
instructions with
respect to format but
not content.
Analysis of the
information
4 5