886017
Descripción
Mapa Mental por charl.mallon, actualizado hace más de 1 año
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Creado por charl.mallon
hace más de 10 años
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B3g: NEW GENES FOR OLD
- SELECTIVE BREEDING
- When humans artificially select the plants or animals that are going
to breed. Organisms are selectively bred to develop the best features
- Maximum yield of mean, milk, grain etc
- Good health and disease resistance
- Temperament
- Speed
- Attractiveness
- Maximum yield of mean, milk, grain etc
- Method
- Select best characteristics from existing stock
- Breed them together
- Select the best of the offspring & breed them together
- Continue until the desirable gene gets stronger and stronger
- Continue until the desirable gene gets stronger and stronger
- Select the best of the offspring & breed them together
- Breed them together
- Select best characteristics from existing stock
- Main drawback: REDUCTION IN GENE POOL
- Reduces the number of different alleles because of inbreeding
- Can cause health problems: more chance of harmful genetic disorders when gene pool is limited
- This is because lots of genetic conditions are recessive (you need two alleles to be
the same) - inbreeding means that recessive alleles are more likely to build up
- There can also be problems if a new disease appears: not much variation = if one suffers it is likely that the others will
- There can also be problems if a new disease appears: not much variation = if one suffers it is likely that the others will
- This is because lots of genetic conditions are recessive (you need two alleles to be
the same) - inbreeding means that recessive alleles are more likely to build up
- Can cause health problems: more chance of harmful genetic disorders when gene pool is limited
- Reduces the number of different alleles because of inbreeding
- When humans artificially select the plants or animals that are going
to breed. Organisms are selectively bred to develop the best features
- GENETIC ENGINEERING
- Moving genes from one organisms to another so that it produces useful biological products
- Advantage: you can produce organisms with new and useful features very quickly
- Risk: the inserted gene might have unexpected harmful effects
- EG: genes are often inserted into bacteria so they produce useful. If these bacteria mutated
and became pathogenic, the foreign genes might make them more harmful and unpredicatable
- People also worry about the engineered genes 'escaping' - e.g. weeds could gain
rogue genes from a crop that's had genes for herbicide resistance inserted into it
- EG: genes are often inserted into bacteria so they produce useful. If these bacteria mutated
and became pathogenic, the foreign genes might make them more harmful and unpredicatable
- Advantage: you can produce organisms with new and useful features very quickly
- Method
- The gene that codes for the desirable characteristic is selected
- It is then cut out (using restriction enzymes) and isolated
- The useful gene is inserted into the DNA of another organism
- The organism then replicates and soon there are loads of similar organisms all producing the same thing
- The organism then replicates and soon there are loads of similar organisms all producing the same thing
- The useful gene is inserted into the DNA of another organism
- It is then cut out (using restriction enzymes) and isolated
- The gene that codes for the desirable characteristic is selected
- EXAMPLES
- Putting beta-carotene (contains vitamin A) from carrot plants into rice plants
- In places in the world which rely heavily on rice for food, vitamin A
deficiency is a problem because rice doesn't contain much vitamin A
- In places in the world which rely heavily on rice for food, vitamin A
deficiency is a problem because rice doesn't contain much vitamin A
- Human insulin into bacteria
- The bacteria are cultured in a fermenter, and the human insulin is extracted from the medium as they produce it
- The bacteria are cultured in a fermenter, and the human insulin is extracted from the medium as they produce it
- Herbicide resistance into useful plants such as crops
- Some weed-like plants have resistance to things like herbicides, frost damage and disease - so it is put into crops
- Some weed-like plants have resistance to things like herbicides, frost damage and disease - so it is put into crops
- Putting beta-carotene (contains vitamin A) from carrot plants into rice plants
- MORAL AND ETHICAL ISSUES
- Some people think it's wrong to genetically engineer other organisms purely
for human benefit, particularly animals, especially if the animal suffers
- People worry that we won't stop: in the future those who can afford genetic engineering might be able
to decide characteristics of their children, and those who can't may become a 'genetic underclass'
- The evolutionary consequences are unknown, so some people think it's irresponsible to
carry on when we're not sure what the impact of future generations might be
- Some people think it's wrong to genetically engineer other organisms purely
for human benefit, particularly animals, especially if the animal suffers
- Moving genes from one organisms to another so that it produces useful biological products
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