Download Genetic Engineering Learning Outcomes Natural Transfer of Genetic

National 5 Biology – Living Cells – Genetic Engineering
Genetic Engineering
Vector, plasmid, gene, genetic engineering, genetically modified (GM),
insulin
Learning Outcomes
You will be able to:

Describe the importance of being able to locate the position of genes on
chromosomes.

Describe the techniques involved in Genetic Engineering and show how
this technology can be used to combine genetic material from two
different species.

Explain how genes can be removed from chromosomes and inserted into
different chromosomes.

Explain why bacterial cells are used in genetic engineering.

Describe how insulin or human growth hormone is manufactured using
bacterial hosts and the benefits arising from this.
Natural Transfer of Genetic Information
Genetic information can be transferred from one cell to another by natural
means. E.g. a copy of a bacterial plasmid (circular molecule of DNA) can be
passed from one bacterium to another and the DNA in a virus can be
inserted into a host cell that is being attacked by the virus. DNA can also be
transferred from one cell to another artificially by genetic engineering.
Genetic Engineering
In recent years scientists have discovered that genetic material can be
transferred artificially from the cells of one species to the cells of another
completely different species using techniques called genetic engineering.
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National 5 Biology – Living Cells – Genetic Engineering
An example of Genetic Engineering
An example that is commonly used to
explain genetic engineering is that of
insulin. Insulin is a protein hormone
produced by the pancreas which helps to
regulate the concentration of sugar in
blood. One form of diabetes results from
some people’s inability to produce
functioning insulin. People with this form
of diabetes must inject insulin into their
bloodstream in order to control their
blood sugar levels.
In the past, the only source of insulin was from animals. It was extracted from
the pancreases of pigs and cows. This was not ideal. Today, people with this
form of diabetes can be given pure human insulin through genetic engineering.
The steps of genetic engineering
1. The gene for a particular protein that you want to produce needs to be
identified in the source chromosome and extracted. Enzymes are used to
cut out the gene.
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National 5 Biology – Living Cells – Genetic Engineering
2. The DNA that has been extracted from a human source must be added to
a vector. A vector is just a piece of DNA which carries our gene.
Bacterial plasmids are common vectors. The plasmid is cut open using an
enzyme, and then the gene is joined to the plasmid.
3. The plasmid can now be inserted into a host cell. Bacterial cells naturally
exchange plasmids and so they will readily take up any plasmids they are
exposed to. Once the plasmid is in the host bacterial cell, the cell will
make many copies of it. When they do this, they unwittingly also make
many copies of our human insulin gene.
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National 5 Biology – Living Cells – Genetic Engineering
4. Given the right conditions, the host bacterial cell will divide. As they do,
they will be making copies of our human insulin gene.
5. The bacterial cells will begin expressing the gene. This means they will
actually make the human insulin protein.
6. The insulin can be collected, purified and then given to people with
diabetes.
Learning Activity 1
1. Name an organism used in genetic engineering.
2. Give an example of a product manufactured using genetic engineering.
3. Describe the use of this product in humans.
4. Describe what a plasmid is.
5. State 2 advantages in using bacteria for genetic engineering.
6. Insert and complete the ‘Genetic Engineering’ diagram into your notes.
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National 5 Biology – Living Cells – Genetic Engineering
Genetically Modified (GM) Organisms
The transfer of genes from one organism into another has been applied more
widely in recent times. Genes have been taken from a wide variety of different
organisms and transferred into various crop plants to improve yield. These are
known as genetically modified (GM) crops.
Crop
Modification & Advantage
Rice
Genes from daffodil and soil bacteria
allow the rice plant to produce vitamin
A in its seeds.
Rapeseed
Genes from other organisms that give
the crop herbicide resistance allow
herbicides to be used to kill weeds
among the crop, increasing yield
Tomato
Soil bacteria carry genes from other
bacteria that code for insecticide
protein into tomato cells, so increasing
yield
Potato
Genes from other organisms give
potato plants fungal resistance, so
increasing yield
GM organisms offer the potential for great benefits to humans but there are
also issues connected to their production and use.
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National 5 Biology – Living Cells – Genetic Engineering
Benefits & Issues with GM organisms
Benefits

GM crops and animals can be higher yielding and better tasting.

They can increase food security for increasing human populations.

They can have a positive impact on the environment through the potential
for decreasing pesticide use.
Issues

There are safety issues related to human health.

Potential for unintented release of genes into wild populations.

Concern of over domination of food production by GM companies.

Ethical issues related to tampering with nature are raised.

Concern that we simply do not know or understand the potential
problems.
Learning Activity 2
1. Construct a table to show a list of genetically engineered food and
medicines. For each example explain the benefit to humans of the genetic
modification.
2. Describe why some people have concerns about the use of genetic
engineering in the production of GM organisms.
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National 5 Biology – Living Cells – Genetic Engineering
Tomatoes with a
longer shelf life
Golden Rice an effective
source of
vitamin A
In groups, choose one of these genetically engineered products or another of
your choice and research it using the Internet.
Making sure everyone has a role, prepare a 5 minute presentation for the rest
of the class including:

A statement of what the product is – include whether it is available or
being developed now

Information about the host organism

Information about the source of the added genetic material

The case for the product

The case against the product

The group’s opinion of the product

A list of References to show that the information you present is from a
reliable source.
Less toxic
rape seed oil
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Blight resistant
potatoes
Humulin effective
control of
diabetes
National 5 Biology – Living Cells – Genetic Engineering
Enviropig
The Enviropig was a pig which has been altered to include genes from E. coli (a
bacterium) and mice.
The inclusion of these genes meant that the pigs were better able to digest their
food, making their manure less harmful to the environment.
This project was closed in June 2012 due to loss of funding.
Extension Task
Use the internet to research some of the more extreme examples of genetic
engineering e.g. Enviropig, venomous cabbage, glow-in-the-dark cats and
medicinal eggs.
Produce a fact-file giving 4 examples of extreme genetic engineering. Include
the following information:
-
The name of the organism
-
Explanation of how the organism is genetically modified
-
Benefits of the modification
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