Transcript 4 Genetic engineering

Genetic
Engineering
TITLE: Genetic Engineering
Objectives
• What is genetic engineering? – grade C-A*
• How are genes transferred from one
organism to another? – grade C-A*
• What are the issues involved in genetic
engineering? – grade C-A*
Outcomes:
• Complete a learning summary fill in the gaps
exercise;
• Label a diagram to show how human insulin
can be produced using genetic engineering;
• Look at modelled exam questions and
complete your own based on the model
KEY WORDS:
Summary – see worksheet
• In genetic engineering, genes from the chromosomes of
humans and other organisms can be ‘cut out’ using enzymes
and transferred to cells of other organisms.
• Genes can also be transferred to the cells of animals,
plants or microorganisms at an early stage in their
development so that they develop with desired
characteristics.
• New genes can be transferred to crop plants
• Crops that have had their genes modified in this way are
called genetically modified crops (GM crops)
• Examples of genetically modified crops include ones that
are resistant to insect attack or to herbicides
• Genetically modified crops generally show increased yields.
Genetically modified organisms
‘GMOs’
• Concerns about GM crops include the effect
on populations of wild flowers and insects,
and uncertainty about the effects of eating
GM crops on human health.
Benefits…
• Crops grow more rapidly and produce more
– there are more people in the world to
feed;
• Pest and disease resistance can be given to
crops to increase yields
• Crops can be given frost / drought
resistance
• Production of medicines that reduce the
risk of rejection and side effects – human
insulin
Maybe we will be able
to genetically engineer
humans to replace
defective genes that
cause genetic diseases.
Cattle and methane
Exam style question
• Scientists are investigating how to reduce
methane emissions from cattle. Most of this
methane is emitted by the cows belching.
• Scientists have found that less methane is
belched if the cows eat high-sugar rye grass.
• This rye grass has been produced by genetic
engineering.
(i) Suggest how the high-sugar rye grass might
have been produced by genetic engineering.
Model answer
• remove gene using enzymes
• from plant with high sugar production
• insert gene into rye grass cells using
enzymes
• (ii) Some people might object to the
growing of genetically-engineered, highsugar rye grass for feeding cattle.
• Give two reasons why.
Model answer
• concern about effect on (health) of cow
• concern about effects on human (health) as
humans eat cow products (dairy / meat)
• concern about food chain effects or effects on
ecosystem
• effect on gene pool
• ignore not natural or cost
• ignore ethical / religious arguments
• if no other marks awarded
‘we don’t know the long term effects’ = 1 mark
TITLE: Genetic Engineering
Objectives
• What is genetic engineering? – grade C-A*
• How are genes transferred from one
organism to another? – grade C-A*
• What are the issues involved in genetic
engineering? – grade C-A*
Outcomes:
• Complete a learning summary fill in the gaps
exercise;
• Label a diagram to show how human insulin
can be produced using genetic engineering;
• Look at modelled exam questions and
complete your own based on the model
KEY WORDS: