1. The Incredible Hulk was a scientist who got caught in
the blast
of a
bomb that he had created. As a result of the explosion, he
becomes transformed into the Hulk, who is a raging
monstrosity with superhuman strength. (picture from:
http://epguides.com/IncredibleHulk/cast.jpg)
2. The X-Men are a team of five teenagers who
were all gifted with special
superhuman like talents. (picture
from:
http://www.zianet.com/comic-booksuperstore/marvel/xmen-ultimate_guide.jpg)
3. Spider man is a boy who gets bitten by a
radioactive spider. The bite gives Peter Parker spider-like
abilities such as shooting a web, crawling/ walking up walls and
superhuman strength. (picture
from: http://bigheadmax.free.fr/wallpapers/images/spiderman.jpg)
4. The
Teenage Mutant Ninja Turtles are four wise-cracking, pizza
obsessed superheroes who fight the forces of evil from their sewer
hideout. (picture
from:
http://content.answers.com/main/content/wp/en/thumb/4/40/300px-TMNTGroup.jpg)
**** Challenge Question:****
Can you name any other mutations
in the entertainment industry? What are their superhuman like
qualities?
So, know
that you know that some of your favorite comic book characters are
mutants:
What is a mutation?
A
mutation is a permanent change in the genetic
information of a living
organism. This can include changes in the DNA of the cell,
which is the molecule in each cell that directs the cell's
activities. Mutations change the numbers, types, or order of base
pairs (A, T, G, and C). They occur during cell division, when the
DNA is copying itself, through a process called replication.
http://contest.thinkquest.jp/tqj1998/10098/image/ori/dna.gif
http://www.historyoftheuniverse.com/images/mutation.gif
How
can mutations affect organisms?
Mutations can affect an organism by
changing
its physical
characteristics (or phenotype)
or it can impact the way DNA codes the
genetic information (genotype).
When mutations occur they can cause
termination (death) of an organism or they can be partially
lethal. This means that the organism has difficulty
adapting to and surviving in its environment.
Mutations are usually the cause of many diseases and
defects in an
organism's life.
Types
of Mutations:
There are many types of mutations
that can be grouped
according to their effects on the structure, the function, and the
physical
characteristics (phenotype)
of an organism. Of these specific
types of mutations, they can be categorized into beneficial (helpful),
less favorable (harmful), and non-effective (neutral) mutations.
Some examples are listed below:
- Helpful Mutations: These
mutations can increase an organism's chance for survival and usually
occur over a course of many generations producing offspring (or babies) with
the helpful mutation. An example of this might be if you were a
tree frog, the ability to camouflage yourself
would prove to be helpful because it would supply protection from
predators because you can blend into your surroundings or
environment. This would allow you to mate and produce
offspring because you would have survived for longer lifespans.
- Harmful Mutations: These mutations
can affect an organism by decreasing it's chances for survival in the
natural environment. For example, if you were an albino tree frog
who
developed a mutation in your DNA for pigment (or coloration of
your skin), you would be easily seen by many
predators whoc could eat you for food. At this point, you
would decrease your chances for
survival and would not have much time to mate and produce offspring.
- Neutral
Mutations: These mutations
do not show any advantages or disadvantages to an organism. In
fact, many organisms may have mutated genes and not know it all because
it does not show through on its phenotype and does not affect the
structure or function of the gene in the cell at all.
<> Can
you tell which picture is an example of a harmful and helpful
mutation?
http://www.animalpicturesarchive.com/Arch01/1084721406.jpg
http://www.alanbauer.com/images/Critters/tree%20frog.jpg
How
do mutations occur and what causes them?
Mutations can
occur in two ways: spontaneously or by
agents
known as mutagens. Spontaneous, or random, mutations occur
because
molecules are constantly moving inside a cell, which can cause
collisions. These collisions can cause interruptions in DNA
replication which can result in damage of DNA information.
Also, because DNA is such a complex molecule, mutations can occur
without any outside influences. However, there are some
other factors that influence the occurrence of a mutation. A
mutagen is an abnormal
factor that changes genetic information. Mutagens are substances
such as x-rays,
ultra-violet radiation, and chemicals that come from cigarette
smoke.
When
damage occurs in a cell, three things can
happen:
1. Enzymes, which
are proteins that speed up a chemical reaction inside the cell, can
repair the
damage
and the cell goes on to function
normally. (No
mutated cell!)
2. The cell can
recognize that it needs to be repaired, but knows it can't fix the
problem. So, it
goes through a process of terminating itself
(also known as apoptosis).
(No
mutated cell!)
3. The enzymes fail
to repair the cell and it does not go through apoptosis. Now, the
cell has
remained damaged and it continuesto divide with a permanent change in
its genetic information.
In other words, a mutation has
occurred.
http://en.wikipedia.org/wiki/Image:Dna-split.png
Frequently
Asked Questions about
Mutations:
- How often do Mutations occur?
- Scientists
are still
researching this question. The frequency of cell division varies
among different types of cells. A mutation will occur more often
in a cell that divides and reproduces every few seconds versus a cell
that reproduces only every few days. Yet, base pairing during DNA
replication happens hundreds to thousands to millions of times in a set
period. Therefore, the possibility for mutations to occur is very
high, but that does not mean it happens.
- Can I get a mutation from someone who has it?
- No! Mutations are not
communicable. That is, you can not get the mutation by contact
with someone who has it. Mutations occur within your own
cells. However, you can inherit a mutated allele (different forms
or versions of a gene for the same trait) from your parents during fertilization
(the joining of an egg and a sperm cell during
reproduction).
- Are there cures for mutations?
- Depending upon the type of
mutation that has occurred, treatment may be possible. Cancer is
a disease caused by mutations and is treatable through radiation and
chemotherapy; yet, there is no definite cure for cancer as of current
dates. Another disease caused by mutated cells is Sickle Cell
Anemia which has treatment methods being used currently, but still no
cure.
- Since the completion of the Human
Genome Project in 2003, scientists have been trying to use the
information about human chromosomes and genes to detect and treat
genetically related disorders and diseases.
- Can mutations kill you?
- Most
mutations that occur
are lethal in the early stages of egg development. However,
death may occur at later periods of the organism's lifespan depending
upon the severity of the mutation.
- Could I have a mutation and not know about it?
- Yes!
There is a
possibility that some of your cells mutated during the course of your
lifespan. More than likely, these are neutral mutations and do
not prove to be helpful or harmful to your survival, so you may not
know bout them at all.
****To learn more about the types, causes, and effects of mutations:
Information for this page was obtained by:
Krogh, D. (2005). Biology: A Guide to the Natural
World. Pearson Prentice Hall. Upper: Saddle River, NJ.
<>
Mutations. (n.d.) Wikipedia: The free encyclopedia.
Retrieved on August 9, 2006 from: http://en.wikipedia.org/wiki/Mutation.
Encyclopedia of Science and Technology. (2002). McGraw Hill:
New York.
Vol. 4 p#151-153 and Vol. 7 p#771-772.