Download Genetic Variation Unit 4

Genetic Variation
Genetic variation is the key to optimizing the human species through the health of individuals.
What?
Definition of genetic variation: “Variations of
genomes between members of species, or
between groups of species thriving in different
parts of the world as a result of genetic mutation”
(Biology Online).
Simply, it is how one’s DNA differs from that of
everyone else around them.
How?
• Genetic variation is achieved through a process
called chromosomal crossover, or simply
crossing over.
• Definition of crossing over: “A process
occurring during meiosis wherein homologous
chromosomes pair up and exchange segments
of their genetic material" (Biology Online).
Since DNA is what instructs one’s body to
develop, variation in the genes that make it up
tell the body exactly how to do that.
Genetic variation is the reason that our physical
characteristics are so different from those around
us, be it eye color, skin tone, hair color, etc.
• During this process, a new form of a gene is
created, and this gene is what tells one to have
certain characteristics.
It also effects attributes you have but can’t see.
Genetic variation is responsible for the
differences in our DNA that make us more or less
susceptible to diseases.
• Crossing over makes the combinations of
different alleles possible, therefore making way
for variation in the genome.
Why?
To combat genetic disease
• If the genomes of two parents are drastically
different, there is naturally a lower probability
of those two parents creating a child that has a
genetic disease. This is due to the fact that
most genetic diseases are recessive, meaning
that both parents must carry the recessive trait
in order for the child to develop the disease.
To combat communicable disease
• Some DNA variations are responsible for
making us more or less susceptible to disease.
Some people simply don’t get sick as often as
others, and this is due to DNA in the immune
system the decides its strength.
Conclusion:
Genetic variation not only plays a key role in the
development of humans looking different, but
also in the functionality of us as individuals. Low
genetic variation results in less ability to fight
disease, and if that variation is so low as to have
the breeding of close relatives, that will also
result in low survival rates and high rates of birth
defects.
Our health is almost entirely dependent of our
genes, and these genes pre decide how we will
perform in life. Having high amounts of genetic
variation in one’s DNA is the key to optimizing
the health of all human beings.
Inbreeding is bad for everyone
• The effects of inbreeding directly represent the
effects of low genetic variation. Inbreeding is
the phenomenon of close relatives copulate.
Since close relatives have DNA that is very
similar to one another’s crossing over would
look very monotone and create a variety of
health problems for any resulting offspring.
These effects worsen when the act is repeated
through generations.
Survival of the fittest
• The helpful traits that we gain from having a
lot of genetic variation each help us adapt to
our environments a little more. The more welladapted to our environments we are, the more
likely we are to survive as individuals; and the
more likely we are to survive as individuals,
the more likely we are to survive as a species.
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Works Cited
"Chromosomal Crossover." Chromosomal Crossover - Biology-Online Dictionary. Biology Online, n.d. Web. 23 Apr. 2017.
Crossing Over. Digital image. Pearson. Pearson Education, Inc., n.d. Web. 23 Apr. 2017.
"Genetic Variation." Genetic Variation - Biology-Online Dictionary. Biology Online, 2005. Web. 23 Apr. 2017.
Mothersbaugh, Leah Rhian. "Eye Color Genetics." Eye Color Genetics. Movable Type, 1 Oct. 2012. Web. 23 Apr. 2017.
Schoeller, Mrtin. Genetic Variability in Faces. Digital image. National Geographic. National Geographic Partners, 15 Sept. 2014. Web.
23 Apr. 2017.
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