marker

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14 Δεκ 2012 (πριν από 4 χρόνια και 7 μήνες)

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Notes pg 26
-
thru end of book

Transforming

Bacteria

Question: What happens during cell
transformation?

Answer: During transformation, a cell takes
in DNA from outside the cell. The
_______________ DNA becomes a
______________ of the cell's DNA.

External

component

Foreign DNA is first_____________ to a small,
circular DNA molecule known as a
plasmid
.

Plasmids are found ____________in some
bacteria and have been very useful for DNA
transfer.

The plasmid has a
______________
marker

a gene that makes it possible to
distinguish bacteria that carry the plasmid
(and the foreign DNA) from those that don't.

joined

naturally

genetic

Example: Diabetic humans don’t produce enough insulin
to control the amount of sugar in their blood. We used to
harvest insulin from horses. Now, however, thanks to
gene splicing we’re able to splice our genes for insulin
production into bacteria. We grow the bacteria in large
vats and produce large amounts of human insulin for a
fraction of the cost.

Transforming Plant Cells

Question: How can
you tell if a
transformation
experiment has been
successful?

Answer: If transformation is successful,
the _________________DNA is integrated
into one of the chromosomes of the cell.

Recombinant

A) In nature, a ________________ exists that
produces tumors in plant cells.

Researchers can _____________the tumor
-
producing gene found in this bacterium and insert
a piece of foreign DNA into the plasmid.

The bacteria with the _______________ plasmid
can then be used to infect plant cells.

bacterium

remove

recombinant

B) When their cell walls are removed,
plant cells in culture will
________________ take up DNA on their
own.

sometimes

C) DNA can also be _____________
directly into some cells.

Cells transformed by either procedure
can then be _________________ to
produce adult plants.

injected

Cultured

Many egg cells are ___________ enough that
DNA can be directly injected into the nucleus.

Enzymes may help to___________ the
foreign DNA into the _______________ of
the injected cell.

DNA molecules used for transformation of
animal and _________ cells contain marker
genes.

large

insert

chromosmomes

plant

DNA molecules can be constructed
with two ends that will
________________ recombine
with specific sequences in the host
chromosome.

The host gene normally found
between those __________
sequences may be lost or
replaced with a new gene.

sometimes

two

Transforming Bacteria

Question: What happens during cell
transformation?

Answer: During transformation, a cell takes
in DNA from outside the cell. The external
DNA becomes a component of the cell's
DNA.

The plasmid has a
genetic marker

a
gene that makes it possible to distinguish
bacteria that carry the plasmid (and the
foreign DNA) from those that don't.

Foreign DNA is first joined to a small,
circular DNA molecule known as a
plasmid
.

Plasmids are found naturally in some
bacteria and have been very useful for DNA
transfer.

Transgenic Organisms

An organism
described as
transgenic,
contains
genes

from other
species.

Question: How are transgenic organisms
useful to human beings?

Answer: Genetic engineering has spurred
the growth of
biotechnology
.

Transgenic Animals

Transgenic animals have been used to study
genes

and to improve the
food supply
.

Mice have been produced with human
genes that make their
immune

systems
act similarly to those of humans. This
allows scientists to study the effects of
diseases

on the human immune
system.

Researchers are trying to produce
transgenic chickens that will be
resistant to the bacterial infections
that can cause
food poisoning
.

Transgenic Microorganisms

Transgenic bacteria
produce important

substances

useful for
health and industry.
Transgenic bacteria have
been used to produce:

insulin

growth hormone

clotting factor

Transgenic Plants

Transgenic plants are now an
important part of our food
supply.

Many of these plants contain a
gene that produces a natural
insecticide
, so plants don’t have to
be sprayed with pesticides.

Cloning

A
clone
is a member of a population of
genetically
identical

cells produced from a
single cell.

In 1997, Ian
Wilmut

cloned a sheep
called Dolly.

Researchers hope cloning will enable them
to make copies of transgenic animals and
help save
endangered

species.

Warning! Studies suggest that cloned
animals may suffer from a number of
genetic defects and health problems.

In class

Do question 32
-
43

pg 46 in workbook

turn in answers as a
HW grade on the
sheet provided.