Advances in Genetics.ppt - ScienceRocks8

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Dec 14, 2012 (4 years and 7 months ago)

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ADVANCES IN GENETICS

Key Concepts


What are three ways of
producing organisms with
desired traits?


What is the goal of the Human
Genome Project?

KEY TERMS


Selective breeding


Inbreeding


Hybridization


Clone


Genetic engineering


Gene therapy


genome

SELECTIVE BREEDING


One of 3 methods used to
develop organisms with
desirable traits


Select organisms with
desirable traits to be
parents of
next generation


Ex:
Corn, dogs


Two selective breeding
techniques are
inbreeding

and
hybridization

INBREEDING


Crossing 2 individuals that have


similar characteristics


Ex. Crossing 2 turkeys that are


both plump and grow quickly
-

offspring are likely
to have
both those desirable qualities


Inbred organisms have alleles that are
very similar
to parents


Inbred organisms are genetically very similar so
they may inherit alleles that lead to
genetic
disorders

HYBRIDIZATION


Breeders cross 2
genetically
different
individuals


Hybrid that results is bred to
have
best traits
from both
parents


Ex. Crossing one type of corn
with large kernels with
another that is resistant to
disease. Result might be
hybrid corn
with both of the
desired traits

CLONING


Clone


an organism that has
exactly the same
genes

as the organism from which it was
produced


Easy to clone
many plants


cut a stem, put it
in soil and water, and it will develop into a new
plant


genetically the same as the parent


Researchers have been cloning animals such
as
sheep, cows, goats and pigs


Click and Clone

GENETIC
ENGINEERING


Genes

from one organism are transferred into
the
DNA
of another organism


Used to produce
medicines

and improve
food
crops

GENETIC ENGINEERING IN BACTERIA


Used to produce
insulin


Bacteria has 1 DNA molecule in the
cytoplasm


Also has small circular pieces of DNA called
plasmids


Scientists insert a
human gene
into the plasmid


The bacteria and all its offspring will now make the
protein

that this gene codes for

in this case
insulin


Since bacteria reproduce very


quickly,
large amounts
of insulin


can be produced

GENETIC ENGINEERING IN OTHER ORGANISMS


Can use technique to
insert genes
into other
animals


Human genes can be inserted into the cells of
cows


The cows will produce the
protein

for which
the gene codes in their
milk


This has been used to produce
the blood clotting
protein

needed by people with
hemophilia


Genes have also been inserted into
plants
to help
them survive in
cold temperatures
and resist
insect pests

GENE THERAPY


Using genetic engineering to correct
genetic
disorders


Involves inserting
copies of a gene
directly into
a person’s
cells


Ex. To treat
hemophilia
, doctors would replace
the
defective allele on the X
chromosome so
the person’s blood would clot normally

GENE THERAPY

HURDLES FOR GENE THERAPY


First, scientists must find the best way to
correct

the genetic defect that is causing the disorder


Correct or increase
the defective cell product


Make diseased cells
weaker


Block operation

of diseased cells


Second


scientists must find a way to
carry
the
g
enetically engineered
DNA
to target cells


Viruses
are an excellent candidate to deliver the genes
because they infect living cells


Virus must be genetically engineered to render it
harmless


CONCERNS ABOUT GENETIC ENGINEERING


Some people are concerned about
long
-
term
effects
of genetic engineering


Ex. Are genetically modified foods safe?


Concerns that they may harm the
environment
or cause
health problems
in humans


Scientists are trying to address these concerns
and learn more about the
effects of genetic
engineering


LEARNING ABOUT HUMAN GENETICS

The Human Genome Project


Genome


all the DNA
in
one cell of an organism


Main goal of Human
Genome Project has been
to identify the DNA
sequence
of every gene in
the human genome


Completed first draft
-

found that we have at
least
30,000

genes
.
Average gene has
3,000
bases

DNA FINGERPRINTING


DNA technology can be used


to identify
people
and show


relationships


DNA is broken down into
small fragments
.
Selected fragments are used to produce a
pattern similar to a
fingerprint


Except for identical twins no 2 people have the
same DNA
fingerprint

SOURCES


http://www.energy
-
dimension.com/12
-
bizarre
-
examples
-
of
-
genetic
-
engineering/