Biotechnology - jflaherty1@kleinisd.net

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22 Οκτ 2013 (πριν από 3 χρόνια και 9 μήνες)

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Biotechnology

Breeding


The first
biotechnology


Selective
Breeding


The breeding of organisms
to produce certain desired
traits in their offspring


Used to
produce a new
breed with a
desired trait


Only the ones
with the desired
trait are
selected to
reproduce


Persian

Inbreeding


Crossing organisms that
have a similar genotype


Used to maintain a
desired set of traits


Can result in
problems and
undesirable traits
(p. 207)

Sharpei

German

Shepherd

Outbreeding
(hybridization)


The crossing of distantly related
organisms


Usually involves two breeds of the
same species

Liger

Mule

Genetic Engineering


Any technique used to
identify or change genes at
the molecular level


Involves the building of
Recombinant DNA


A molecule made from
pieces of DNA from
separate organisms

All genetic engineering
experiments share 4 steps:


Cleaving DNA



a
desired gene is cut from
DNA


Producing
Recombinant DNA



DNA fragment is put into
the DNA of another cell


Cloning cells



growing a
large number of genetically
identical cells from a single
cell


Screening cells



cells
that received the gene of
interest are identified and
isolated


Example:


The gene for
human insulin
can be isolated
and inserted
into a plasmid



Bacterial cells then
produce human insulin


This is used by people who are
diabetic


Reduces the need for pig
insulin which can cause allergic
reactions


Transgenic Organisms


Organisms that contain
genes

from other species


Ex. Bacteria


gene for
human insulin


Ex. Mice with human
immune genes to study
immune system

Identifying Sequences in
DNA


DNA Fingerprint


DNA is cut into
fragments by a
restriction
enzyme


Because of differences in
nucleotide sequences, the
number of cutting sites for a
restriction enzyme varies
among the DNA of different
individuals producing
fragments of different
lengths


The lengths are
unique

to
each individual


Samples are separated by a
process called
Gel
Electrophoresis

a. DNA fragments are dropped
into thin slits in a track of gel

b.
The gel tracks have a (+)
charge at one end and a (
-
)
charge at the opposite end

c.
DNA has a (
-
) charge so the
fragments move toward the
(+) end of the gel

d.
The smallest fragments move
farthest along the tracks and the
larger fragments stay toward the
(+) end

e. A unique banding pattern is
produced

f. Every person’s DNA has a unique
pattern that can be used for
identification


Cloning


Clone
: A member of a
population of
genetically

identical

cells

produced
from a single cell


First cloned mammal


Dolly
, the sheep

A donor cell is taken

from a sheep’s udder.

A donor cell is taken

from a sheep’s udder.

Donor Nucleus

These two cells are
fused using an electric
shock

Fused Cell

Egg Cell

The nucleus
of the egg
cell is
removed.

The fused
cell begins
dividing
normally.

Embryo

The embryo is
placed in the
uterus of a foster
mother.

Foster
Mother

The embryo
develops
normally
into a
lamb

Dolly

Cloned
Lamb

An egg cell is
taken from an
adult female
sheep.

EXAMPLES OF
BIOTECHNOLOGY IN
MEDICINE AND AGRICULTURE


After listening to some of these examples
of biotechnology in medicine and
agriculture, select
three

examples to
include in your notes.

Making genetically

engineered drugs


The human gene for
insulin can be inserted
into bacteria so the
bacteria produce human
insulin


Human insulin is the
first commercial
product of genetic
engineering


Genetically
engineered
Factor
VIII

is used to
treat hemophilia
patients


This helps blood
to clot but is free
of viruses (HIV
and Hepatitis B)
which could be in
donated clotting
factors.


Making genetically
engineered vaccines


Bacteria are genetically
engineered to act as antibodies
and are safer than using a
weakened form of a disease
-
causing virus


Helping treat the disease
Cystic
Fibrosis



Secretion of excess mucus in
the lungs caused by a
malfunctioning gene


This method has already had
some success


Healthy genes that have
recombined with certain viruses
or carrier cells can be delivered
to lung cells via a nasal spray


The healthy genes can replace
the malfunctioning genes,
correcting the genetic defect


Making crops resistance to
herbicides and insects


The gene that is resistant
to herbicides is inserted into
plants


The farmer treats the field
with an herbicide and
everything dies except the
plants with the new gene


Makes weed control easier

Making crops that need
no fertilizer


Genetically engineering
crops to fix nitrogen


Crops can be grown
without adding fertilizer