Slide 1 - El Camino College

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14 Δεκ 2012 (πριν από 4 χρόνια και 10 μήνες)

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Biotechnology


Altering biological
molecules, cells,
organisms


Genetic Engineering
-

modification of genes: Change,
delete, insert genes


1. To learn more about cellular processes


2. To better understand and develop treatments of diseases


3. For economic and commercial benefits


Recombinant DNA


recombining or rearranging
genes for manipulations, in the same or different
organisms


Transgenic



organisms that express recombinant
DNA



1. Genomics


genome

is the full genetic information of an organism


sequence of the entire human genome (2000)


More than
3 billion base pairs


between
20K and 30K

protein
-
encoding genes

2. DNA Fingerprinting



Forensics


Cut person’s DNA and analysis of fragment because
every person has a unique DNA fragment pattern due
to unique DNA sequence


Collect samples


Cut DNA with Restriction
Enzymes

Run cut DNA through gel:
Fragments move through gel

Separated by size


#1

#2

Larger

fragments

Smaller

fragments

3. Genetic Engineering
-
Medicine


genetic engineering has focused to improve medicine:


production of proteins

(drugs) used to treat illness


creation of
new vaccines

to combat infection


replacement of
defective genes

(i.e.,
gene therapy
)


genetic defects
occur because our cells fail to
make critical
proteins, such as
diabetes


diabetics cannot control their blood sugar levels because a
critical protein,

insulin
, is not made


failure can be overcome by receiving insulin made
through genetic engineering


Genetic engineering creates
vaccines

against viruses,
such as
herpes

and
hepatitis



Gene transfer therapy


involves introducing “healthy” genes into cells that
lack them


With adenovirus was
unsuccessful

in humans
because of immune attack


Human gene +

virus DNA:
Recombinant

DNA



Put into

unhealthy

individual


4. GM food
-
Agriculture


made plants more
resistant
to disease


improved
nutritional

content and yield


made crops hardier and
better able to resist
environmental

stresses


supertomatoes
with

genes from soil
bacterium produce a protein toxic to
crop pests



“golden” rice
combat iron and vit A
deficiency with genes from a
bean, a
fungus, wild rice, and a daffodil

to
increase its nutritional value

5. Cloning


nuclear
transplants

of a
nucleus from an
animal cell into the
an enucleated egg


Wilmut
-
Campbell:

cloned a sheep
using the mammary
cells of an adult


6. Embryonic Stem Cells


special cells
-

Totipotent:



ability to form any body tissue and restore damaged
tissues


each has the capacity to develop into a healthy
individual


form early in development



Using
embryonic
stem cells to
restored
damaged
tissue

As genetic engineering advances, the

ethical questions

of the technology

increases

Practice questions

Question 1


The total amount of DNA in an organism, including all of its genes and other DNA, is its
A)
heredity.
B)
genetics.
C)
genome.
D)
genomics.


Question 2


A possible reason why humans have such a small number of genes as opposed to what was anticipated by scientists is that
A)
humans don't need more than 25,000 genes to function.
B)
the exons used to make a specific mRNA can be rearranged to
form genes for new proteins.
C)
the sample size used to sequence the human genome was not big enough, so the number of
genes estimated could be low.
D)
the estimate will increase as scientists find out what so
-
called "junk DNA" actually does.


Question 3


A protein that can cut DNA at specific DNA base sequences is called a
A)
DNase.
B)
DNA ligase.
C)
restriction enzyme.
D)
DNA polymerase.


Question 4


The four steps of a genetic engineering experiment are (in order)
A)
cleaving DNA, cloning, producing recombinant DNA,
and screening.
B)
cleaving DNA, producing recombinant DNA, cloning, and screening.
C)
producing recombinant DNA,
cleaving DNA, screening, and cloning.
D)
screening, producing recombinant DNA, cloning, and cleaving DNA.


Question 5


Using drugs produced by genetically engineered bacteria allows
A)
the drug to be produced in far larger amounts than in the
past.
B)
humans to permanently correct the effects of a missing gene from their own systems.
C)
humans to eliminate the
chances of infection from blood transfusions.
D)
All of these answers are correct.


Question 6


Some of the advantages to using genetically modified organisms in agriculture include
A)
increased yield.
B)
unchanged
nutritive value.
C)
the ease of transferring the gene to other organisms.
D)
the possibility of anaphylaxis.


Question 7


Which of the following is
not

a concern about the use of genetically modified crops?
A)
possible danger to humans after
consumption
B)
insecticide resistance developing in pest species
C)
gene flow into natural relatives of GM crops
D)
harm to
the crop itself from mutations


Question 8


Genomic imprinting seems to involve
A)
protein signals that block transcription of a gene from its DNA.
B)
proteins that
cause deformation of RNA polymerase.
C)
methylation or demethylation of RNA polymerase.
D)
methylation or
demethylation of DNA.


Question 9


One of the main biological problems with replacing damaged tissue through the use of embryonic stems cells is
A)
immunological rejection of the tissue by the patient.
B)
that stem cells may not target appropriate tissue.
C)
the time needed
to grow sufficient amounts of tissue from stem cells.
D)
that genetic mutation of chosen stem cells may cause future
problems.


Question 10


In gene therapy, healthy genes are placed into cells with defective genes by using
A)
bacteria.
B)
micropipettes (needles).
C)
viruses.
D)
Currently, cells are not modified genetically. Instead, healthy tissue is grown and transplanted into the patient.