Download Genetic Engineering

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)
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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:
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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
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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

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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 itsA) 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 thatA)
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 aA) 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 allowsA) 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 includeA) 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
consumptionB) insecticide resistance developing in pest speciesC) gene flow into natural relatives of GM cropsD) harm to
the crop itself from mutations
Question 8

Genomic imprinting seems to involveA) 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 isA)
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 usingA) bacteria.B) micropipettes (needles).C)
viruses.D) Currently, cells are not modified genetically. Instead, healthy tissue is grown and transplanted into the patient.