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PowerPoint Notes: Standard 4, Objective 3
Slide 1:
We learned about DNA and the basis of its structure when we talked
about biological macromolecules, what do you remember? What are the
monomers called? What are the parts of the monomer? How do they
connect to make a polymer? What are they two types of polymers? The
GATC code provides instructions for cell structure and function.
Slide 2:
Line up base pairs and talk about where the connections (bonds) are and
how they bond together. Label the parts of the DNA structure (backbone
and rungs). Discuss the idea of anti-parallelism that the two strands are
opposite to each other. Discuss the length of these molecules and that in
the human genome that if all DNA from one cell was lined up end to end it
would be 3 meters (over 6 feet) long.
Slide 4:
Replication – DNA splits in half and nucleotides come in to fill in the
blanks. This happens in the nucleus during Interphase. Accurate
replication is important to the correct transmission of traits.
Slide 5:
DNA makes proteins. It also has other functions like development and
function of the organism.
Transcription – DNA can’t leave the nucleus but proteins are made in
ribosomes outside of the nucleus… we have a problem. We need a way
for the DNA code in the nucleus to get to the ribosomes. THIS IS WHERE
RNA APPEARS.
There are different kinds of RNA and the first we’ll learn about today is the
mRNA (messenger RNA). DNA transcribes codes into RNA molecules
that can leave the nucleus.
RNA molecules are different from DNA (single strand, thymine replaced by
uracil, can leave nucleus). RNA provides the code for amino acids to form
proteins. Enzymes are made from proteins and control reactions in the
cell.
Slide 6:
Messenger RNA (mRNA) - the messenger that brings DNA from the
nucleus to the ribosome. Talk about how the information is passed and
introduce URACIL.
Translation – mRNA meets the ribosome and tRNA (transport RNA)
comes in to bring the appropriate amino acids. These form chains that
become the complex proteins we learned about.
Slide 8:
A mutagen is a physical or chemical agent that changes the genetic
material and increases the frequency of mutations above the natural
background level. Many mutations cause cancer.
Slide 9:
Spontaneous mutations occur due to errors in DNA replication, repair or
recombination.
Slide 15:
Reproductive Cloning: Pros
1) Parents with no eggs and sperm can create children that are genetically
related
2) Same sex couples can have children without the use of donor sperm or
donor eggs
3) The men would only require a surrogate to carry the clone until birth
4) Parents that have lost a child can have that child returned to them with
a clone
5) Endangered animals can be cloned to save the species
Organ Replacement:
Many believe that cloning can be used to replace failing organs. This will
diminish the waiting list for organ donations and allow more people to be
saved. Not only that, but because the organ is, in fact, your own organ,
there would be less chance of rejection. Your body would recognize the
new organ as your own.
Genetic Research:
Cloning could prove helpful in the research of genetics. Using cloning
technologies, genetic researchers would have a better understanding of
the composition of genes and the effects of genetic constituents on human
traits. There is also the likely ability to alter genetic constituents in cloned
humans, and cloning could help combat genetic diseases.
Obtaining Desired Traits in Organisms:
With the use of cloning, organisms can be customized to suit the needs of
whatever research purposes being done. Using genetic alteration in plants
and animals, researchers can replicate organisms needed for research.
No longer would there be the worry of scientists harming creatures
because these creatures would be cloned specifically for the purpose of
research.
Recovery from Traumatic Injury:
Healing and recovery times could be lowered because of cloning. Using
the person’s own cells, they will be able to recover that much faster and
that much easier. Using their own cells, they would be given the chance to
truly heal with less complications.
Slide 16:
Reproductive Cloning: Cons
1) Cloning children could foster an understanding that children can be
designed and replicated to the parents’ wishes. There would be a lack of
uniqueness and violate convictions regarding human individuality and
freedom. Clones could be seen as less than human compared with nonclones
2) Children created by cloning would live in the shadow of the genetic
donor, always having to live up to the expectations of a person they were
created from. Imagine discovering that you are the clone of a child your
parents lost, and you live your life always being compared to the dead
child
3) 95% of animal cloning has ended in failure due to genetic defects, and
cloning is considered unsafe because of it
4) Many believe that cloning is against God’s wishes because the clones
would be created by man. Man would be playing God and create people
that are unable to feel and empathize. There is also the belief that these
clones would be created without a soul.
Increased Malpractice:
While the cloning of body organs can be a great asset to extending human
life, it could also cause a lot of malpractice. Along with the ability to clone
desired traits, there could be the possibility of people deliberately
reproducing undesired traits. This could lead to a rise in malpractices
within society.
Lack of Diversity:
Cloning involves a process of creating identical genes. As such, there
would be a lack of diversity in humankind. Scientists believe this lack of
diversity will lower the human race’s ability to adapt. Plus, there would be
a lack of diversity in the world leading to everyone looking the same.
Faster Aging:
The idea behind cloning is to harvest cells from a donor, raise them to
embryonic stage in a petri dish, and then place them in a surrogate to
grow to term. However, there is a possibility that the age of the donor
could be imprinted on the growing embryo. Tis would cause premature
aging issues and potentially lead to premature death.
Security:
People shed millions of cells throughout their day as their skin cells fall off.
You can leave skin cells even on a computer keyboard, and those cells
could be used to clone you if cloning becomes a reality. What laws would
there be to defend your rights as the true non-clone compared to the
clone? Would there be any defense against people collecting cells and
cloning random people?
Studies show that the clone would in fact not be completely identical to the
original, just as twins are not completely identical. Though they might look
alike, twins have different personalities and enjoy different things. The
same would be said of clones. Even if technology were created in which
your memories and thoughts could be transmitted to the clone, your clone
would still be a different person.