U3 Key Area 5- Food Production Flashcards
How is the human population different to other predations
The human population is different from all other predations in that a number of the selection pressures have been overcome.
What stuff have we developed to help with survival (2)
- we have created and developed areas for food production to prevent starvation
- we have developed medicines to combat diseases
What are nitrates
Very important chemicals found dissolved in water
How are nitrate used for protein synthesis (3)
- Nitrates are absorbed into the root of the plant and then used to produce amino acids.
- Theses amino acids are then synthesised into plant protein for growth and repair.
- Animals can consume plants (or other animals) to obtain amino acids for their own proteinsynthesis.
What are fertilisers
Fertilisers are chemicals added to soil to increase nutrients such as Nitrates
The more the nutrients grow….
The more it van grow which means the more food there will be to feed a growing population
What is one of the main problems with fertilisers
Leaching
Algal bloom summary (7)
- Nitrates in fertilisers leach into water ways
- Increased growth of algae forming algal bloom on surface of water.
- Algal bloom blocks sunlight from entering water
- Dead plant can’t photosynthesis which means more bacteria
- Bacteria use up large quantities of oxygen when decomposing dead plants
- Less oxygen available for other organisms such as fish
- Reduction in biodiversity
How does algal bloom occur
This happened when water can carry fertilisers and run off the land (leach) into rivers and locks. This will increase the population of algae in the water and results in algal bloom
Problem with pesticides
some pesticides can have adverse effects on populations e.g. DDT
What is DDT
The pesticide DDT was used a lot during and after WW2 but it was discovered that it build up in bodies and animals that ate plants containing it.
What happens to the food chain when Bioaccumulation occurs
As the pesticide travels along the food chain, the level of toxicity increase and can reach lethal levels. This can often be fatal for the top carnivores.
What is an alternative of pesticides
Biological control
What is biological control
This is the deliberate introduction of a predator or parasite of a pest
Advantages of biological control (3)
- No chemicals being added to the food chains
- The introduced predator is specific to the particular pest being dealt with
- It is much cheaper after the initial set-up costs
What are pesticides
Pesticides are important chemicals used in farming to kill plants and animals which reduce crop yield
What is the biological control for aphids
The biological control is a ladybird and the outcome is that the ladybird eat the aphids that are damaging the crops
What is the biological control for cactus
The biological control of cactus moth caterpillar which have the outcome of the caterpillars stop the spread of the cactus
What is the biological control for rabbits
The biological control of myxomatosis and the outcome is myxomatosis kills the rabbits that are eating the crops
What are the disadvantages of Biological Control (3)
- Sometimes, the introduced species can, itself, become a pest
- It doesn’t guarantee that all pests will be killed.
- The introduced predator can leave the environment
What can GM crops used to reduce
The use of fertilisers and pesticides
What can GM crops used to increase
Their yells and so can reduce the need to use a fertiliser or pesticides
Why do cauliflowers become genetically modified
Scorpion genes to kill insects
Why do rice become genetically modified
Has vitamin A in it to help children get that vitamin in their diet
Why do maize become genetically modified
Drought resistance so it can grow in deserts
Why do tomatoes become genetically modified
So there is a bigger yield (more produced)
What is bioaccumulation
The build-up of toxic substances in bodies of animals that ate plants containing it
