IGCSE Biology Triple Science Notes
Use of Biological Resources
Contents:
Food Production
Selective Breeding
Natural Selection
Genetic Modification
Cloning
, Wallace's line is a biogeographic boundary separating Asian animals from Australian
animals. There is a sudden change in fauna across a 35km boundary.
The DDT insecticide resistance happened in insect survivors of pesticides. Only the
strongest survived thus making them resistant to the pesticide which let them eat crops.
Antibiotics select for resistance in bacteria, thus letting there be an evolution of superbugs. If
you take antibiotics, to kill bacteria including a resistant variety, making most of the bacteria
die, thus making the resistant bacteria multiply to become more common, thus making the
entire infection evolve into becoming a resistant strain.
Around 150,000 years ago, the polar bear evolved from the brown bear species. The polar
bears now have a great smell to identify prey, strong legs to help them swim in the water,
thick and sandpaper-like paws to grip the slippery ice, and giving the polar bears thick fur to
keep the warm and blend them into the snow. Selective Breeding is best described as the
breeding of only individuals with desired features.
Selective breeding began in 10,000 BC when organisms with favoured traits were allowed to
reproduce. Throughout the 1850s, inbreeding began, and in 1928, mutation breeding was
introduced in plants. They were subjected to UV rays. HYBRIDIZATION is the breeding of
dissimilar organisms to produce hybrids. Inbreeding is the breeding of similar or related
organisms. Mutation breeding is subjective of plant seeds to UV rays and letting them
grow.
A Crop Plant is a plant which is bred to produce strains which give higher yields, are
resistant to some diseases, are resistant to some insect pest damage, are hardier (survive in
harsher climates) and have a better balance of nutrients in crops.
How glasshouses and polythene tunnels increase the yield of crops:
1. Controls humidity so that it is not too hot
2. These things are controlled by farmers:
1. Light
1. farmers can put extra light in
2. thus inc photosynthesis
2. Temperature
1. use heaters
2. optimum temp for enzymes to photosynthesise due to the greenhouse
effect
3. CO2 concentration
1. any heaters will increase CO2 concentration
2. thus inc photosynthesis
4. Water Supply
1. humidity too high
2. breeds fungi
3. less water lost via transpiration
4. becomes more moist
Factors controlled in a greenhouse:
Use of Biological Resources
Contents:
Food Production
Selective Breeding
Natural Selection
Genetic Modification
Cloning
, Wallace's line is a biogeographic boundary separating Asian animals from Australian
animals. There is a sudden change in fauna across a 35km boundary.
The DDT insecticide resistance happened in insect survivors of pesticides. Only the
strongest survived thus making them resistant to the pesticide which let them eat crops.
Antibiotics select for resistance in bacteria, thus letting there be an evolution of superbugs. If
you take antibiotics, to kill bacteria including a resistant variety, making most of the bacteria
die, thus making the resistant bacteria multiply to become more common, thus making the
entire infection evolve into becoming a resistant strain.
Around 150,000 years ago, the polar bear evolved from the brown bear species. The polar
bears now have a great smell to identify prey, strong legs to help them swim in the water,
thick and sandpaper-like paws to grip the slippery ice, and giving the polar bears thick fur to
keep the warm and blend them into the snow. Selective Breeding is best described as the
breeding of only individuals with desired features.
Selective breeding began in 10,000 BC when organisms with favoured traits were allowed to
reproduce. Throughout the 1850s, inbreeding began, and in 1928, mutation breeding was
introduced in plants. They were subjected to UV rays. HYBRIDIZATION is the breeding of
dissimilar organisms to produce hybrids. Inbreeding is the breeding of similar or related
organisms. Mutation breeding is subjective of plant seeds to UV rays and letting them
grow.
A Crop Plant is a plant which is bred to produce strains which give higher yields, are
resistant to some diseases, are resistant to some insect pest damage, are hardier (survive in
harsher climates) and have a better balance of nutrients in crops.
How glasshouses and polythene tunnels increase the yield of crops:
1. Controls humidity so that it is not too hot
2. These things are controlled by farmers:
1. Light
1. farmers can put extra light in
2. thus inc photosynthesis
2. Temperature
1. use heaters
2. optimum temp for enzymes to photosynthesise due to the greenhouse
effect
3. CO2 concentration
1. any heaters will increase CO2 concentration
2. thus inc photosynthesis
4. Water Supply
1. humidity too high
2. breeds fungi
3. less water lost via transpiration
4. becomes more moist
Factors controlled in a greenhouse:
