Advances in Genetics.ppt -


12 déc. 2012 (il y a 9 années et 1 mois)

401 vue(s)

Advances in

By: Tess Branning,
Patrick Dancel, and
Romy Sidelsky

Identical Twins

Except for identical twins, all people have
different DNA.

Identical twins have identical DNA. They come
from the same fertilized egg, which had only one
complete set of DNA in the first place. That
fertilized egg and its single set of DNA split to
form twin embryos
each with its own set of DNA,
identical to the other.



A genome is all the
DNA in an organism,
including its genes.
Genes carry
information for making
all the proteins required
by all organisms. These
proteins determine,
among other things,
how the organism
looks, how well its body
metabolizes food or
fights infection, and
sometimes even how it

Goal for The HGP

The main goal of The Human Genome
Project is to prepare an encyclopedia that
shows the DNA sequence of every gene.

The HGP was completed in 2003 after 13
years of studies. In the earlier years, the
U.K. became an important partner in HGP,
additional contributions came from Japan,
France, Germany, and China.


DNA Fingerprinting

DNA fingerprinting is a term that has
been used in the scientific world for many
years. It is basically a way to find out if
the DNA from one piece of evidence is a
match to the other DNA. Ninety
percent of human DNA is identical
between individuals, but the 1% that
differs enables scientists to distinguish

The DNA alphabet is made up of four
building blocks

A, C, T and G, called
base pairs, which link together to string
long words.. The order in which these 4
DNA letters are used determines the
meaning (function) of the words, or
genes, that they spell.


Solving Crimes with Fingerprinting

Solve this crime…

DNA Fingerprinting is used to identify people. It is a technique
that measures a person’s DNA. Everyone except for identical
twins has a unique genetic code. This means that DNA
fingerprints are almost always unique. DNA extracted from a
person’s cells

such as cheek, skin or blood cells

can be
used to generate a DNA fingerprint.

DNA fingerprinting has widespread applications. Most
commonly it is used to identify criminals, to establish paternity
and to identify dead bodies. It is not only used to identify
humans, it can be used to identify anything that contains DNA.

Identifying DNA

In all DNA results, the
strands of DNA are set into
lanes with gel. The DNA
forms a band, or the white
lines on the gel.

The pieces of DNA can then
be separated according to
their size on a gel. This is
how you identify if the DNA

The smallest pieces travel
the furthest and are
therefore closest to the
bottom of the gel. The larger
pieces travel shorter
distances and are closer to
the top.

(ABOVE: DNA from six
different people. )

Genetic Engineering in Bacteria

Genetic engineering
: The control of all
the normal activities of a bacterium
depends on its single chromosome
and the small rings of genes which are
called plasmids. In genetic
engineering, pieces of chromosome
from a different organism can be
inserted into a plasmid. This allows
the bacteria to make a new

Genetic Engineering Steps

Steps In Genetic Engineering (Picture To
The Right)

1)The gene the genetic engineers want may be in a
human chromosome. It might be the gene for
insulin production.

2)They use an enzyme to cut the insulin gene out of
the chromosome.

3)Plasmids are then removed from bacterial cells

4)The plasmids are cut open with an enzyme

5)A human insulin gene is inserted into each

6)The genetic engineers encourage the bacteria to
accept the genetically modified plasmids

7)Bacteria with the insulin gene are then multiplied

8)Each bacterium will produce a tiny volume of

9)By culturing the genetically engineered bacteria
limitless supplies of insulin may be produced.

Other Uses of Genetic Engineering

Genetic engineering is used for the
production of substances which
used to be both expensive and
difficult to produce, some examples

1)Insulin for the control of diabetes

2)Antibiotics such as penicillin

3)Various vaccines for the control of

Benefits of Genetic Engineering

Insulin is a particularly successful example of the benefits of genetic

The need for insulin is rapidly increasing for these reasons:

1) Diabetes often does not occur until old age

2) People live longer and better treatment means many more patients
survive to old age

3) The world population is increasing

In addition to the fact that genetically engineered bacteria are able to
produce as much insulin as is needed, there are other advantages.

Some of these are:

1) Purifying insulin from the pancreas of slaughtered cattle and pigs was
slow and expensive

2)Production from genetically modified bacteria is both quick and relatively

3) Some patients were allergic to animal insulin

4) Some patients did not like using a product form slaughtered animals

5) The insulin produced by bacteria as a result of genetic engineering is
pure human insulin

Advantages of Genetic Engineering

Genetic engineering has several
advantages over selective breeding. Some
examples include,

1) Particular single characteristics can be

2) The selection may be quicker

3) A desirable characteristic can be
transferred from one species to another

Dangers of Genetic Engineering

There are dangers involved with
genetic engineering since it involves
creating completely new strains of
bacteria. There is a possibility of
creating some which are harmful to
animal or plant life.

Gene Therapy

Gene therapy is used
by researches to try
to correct some
genetic disorders. It
involves inserting
working copies of a
gene directly into a
cells of the person
with the genetic

Games and Movies

Human Genome Movie

DNA Building Games


Cornell University

Singapore Science Centre

Human Genome Information

The Naked Scientists

DNA Interactive

Scotland University

Lasker Foundation