importance of variation?

Question

explain the importance of variation of meiosis and mitosis,
I've searched the internet and I could't find for what I was looking for.

any help will do thank you.

Answer 1

Variation is necessary for organisms to be able to withstand changes in the environment. If environmental changes happen and all the organisms are alike, they'll either all make it or they'll all die. With variations, some individuals may have exactly what they need in order to surve the change.

Meiosis allows for variation because it makes reproductive cells that will join with other reproductive cells. This makes new combinations of genes and chromosomes.
--During meiosis the homologous chromosomes separate randomly, so a gamete gets one of each homologous pair at random. This is Mendel's idea of independent assortment.
--During meiosis I the synapsed chromosomes that form a tetrad undergo crossing over. This changes the combinations of genes and increases variation, too.

Mitosis is supposed to divide the doubled nuclear material exactly evenly so the two resulting daughter cells are identical. Without variation, the cells have no way to survive adverse environmental conditions.

Answer 2

Hope this is of help.


www.life.umd.edu/classroom/biol106/jensen/via/syllabus/ViaLect4.html
A portion of the info follows:

BSCI 106 Dr. Via Spring 2000

Lecture 4. Patterns of Inheritance: Mitosis, Meiosis, Mendel

1. What is transmission genetics and why do we care??

a. "Transmission genetics" is the set of mechanisms by which genes are transmitted between dividing cells and from parents to offspring.

b. These genetic rules govern not only how traits are inherited, but determine genetic variation in populations

c. This genetic variation is the raw material for evolution!

2. Terminology (see back)

a. Chromosome, gene locus allele

b. Homologous, homolog

c. Homozygous, heterozygous

d. Recessive allele, dominant allele

e. Genotype, phenotype

3. Differences between mitosis and meiosis (YOU MUST KNOW THIS COLD, see handouts and your text)

a. Mitosis occurs during cell division of somatic (body) cells for growth and repair.

b. Meiosis occurs in germ cells during the production of gametes.

c. Mitosis leads to 2 diploid (2N) cells identical to the original cell.

d. Meiosis leads to 4 haploid (N) gametes, each with one copy of every chromosome. None of these chromosomes are necessarily identical with any in the original cell due to recombination (much more later)

e. Mitosis -- one cell division. Meiosis-- two cell divisions.

f. A key mechanistic difference between mitosis and meiosis: during the first division (Metaphase in mitosis, Metaphase I in meiosis), chromosomes line up differently!!

g. Follow individual alleles through mitosis and meiosis, without and with crossing over (recombination) during Prophase I of meiosis. Be sure that you can do this!

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Notes: A Comparison

Event Mitosis Meiosis
DNA replication interphase interphase
# of divisions 1: pro-, meta-, ana-, and telophases 2: 1) pro- to telo, 2) then meta- to telo
# of daughter cells 2 diploids 4 haploids
Bodily importance development, growth, tissue repair gamete production (reduce chromosome # by half, introduce genetic variation into the gametes)
http://library.thinkquest.org/C006669/data/Biol/meiosis_5.htm
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CiteULike: GLD-3 and control of the mitosis/meiosis decision in the ...
To address the relative importance of these two regulatory mechanisms in the mitosis/meiosis and sperm/oocyte decisions, we isolated ...
www.citeulike.org/user/stevanspringer/article/205612
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meiosis
6. Genetic variation. mitosis - conservative process; does not lead to genetic variation meiosis - leads to increased genetic ...
mrskingsbioweb.com/meiosis.html · Cached · Save
The Cell Division Unit
5.) Explain the importance of genetic variation during meiosis and why this variation does not occur in mitosis ...
www.msu.edu/~vogtjeff/biology/unit_pages/unit_outline_cell_divisi... www.msu.edu/~vogtjeff/biology/unit_pages/unit_outline_cell_division.htm · Save
Advanced Placement Biology at the University of Georgia
... the key mechanical and genetic differences between meiosis and mitosis ... compare and contrast the results of meiosis and mitosis in ...
apbio.biosci.uga.edu/lab/lab-obj.html · Cached · Save
Reproduction
... a process, the importance of variation, the nature of adaptation, and the ... of cell division, mitosis vs. meiosis, occur in the two ...
uts.cc.utexas.edu/~bramblet/ant301/three.html

Answer 3

challenging stuff. look into google or bing. that can assist!