Topic N: Mans use of Biological Resources Flashcards
How do Glass Houses used to create better conditions for plants?
This is done by creating artificial conditions in a glasshouse by giving the plants the perfect conditions in order to perform photosynthesis and respiration at good rates.
How can the rate of photosynthesis be increased in a glass house?
- Keeping plants indoors in order to protect them from pest and diseases.
- Artificial light is used to give the crops more light at night.
- Glasshouse are able to trap the heat of the sun.
- Carbon dioxide levels are increased.
- Use heater.
How is artificial light made in a green house?
The farmer uses artificial lights which can run up to 24 hours a day in order to provide extra light for photosynthesis. This is going to increase the rate of photosynthesis.
How is Carbon dioxide and heat created in a Greenhouse?
Paraffin heaters are used. These are also used to heat and also the paraffin burns and as a by product, carbon dioxide is created. Carbon dioxide is also going to increase the rate of photosynthesis and the heat is able to increase the rate of all reactions in plants.
Why are fertilizers used?
Fertilizers are used to ensure that plants have enough Nutrients.
What elements do plants need to function properly?
- Nitrogen, potassium and phosphorus. These can all be used for plant growth.
Why do plants need elements to function properly and what do the farmers do to restore the elements?
if they don’t get enough of these elements then there growth and development are effected. The elements may be missing because they have been soaked up from the last crop. Farmers then use fertilizers to restore the elements.
How do fertilizers enter the food chain?
fertilizers may enter the food chain through plankton. They are then eaten by larger fish and the levels of fertilizer concentration increase. the levels of fertilizer concentration increase as you go up the food chain. Also known as DDT levels.
How does Pesticides work?
Form of chemical pest control. There often poisonous to humans and they must be used sparingly in food not to reach dangerous levels. Some harm other wildlife.
How does Biological control work?
Alternative to pesticides. It means using other organisms to reduce the numbers of pests, by encouraging more wild organisms or adding new ones. These could be predators, e.g. ladybirds or parasites e.g. flies or pathogen e.g. bacteria. It is long lasting control.
Why is there a need for tanked fish?
This is because there is now dangerously low supply’s of many fish in UK waters due to over fishing.
What is different about farmed fish?
Kept in optimum conditions. However they are given antibiotics and additives.
What are open fish farms?
- Open area in a lake or pond where fish are kept.
- Fish must have water supply, fresh water from river etc.
- It is free from deasise.
- There are no predators.
- No pesticides and chlorine.
- No competitors.
What is done to grow farmed fish?
- Animal manure is added to encourage growth of pond weed.
- After 4-6 years the fish are normally ready to eat.
How are the fish reproduced?
An enclosed system has large tanks, eggs and sperm are removed, these are then mixed in a laboratory and are moved into hatching tanks. As the fish grow they are moved to different tanks before reaching a suitable size where they are released into the main tanks.
Advantages of fish farming?
- production of food on a large scale.
- Controlled feeding
- Pests and desises can be treated.
- Highly efficient conversion of feed to protein in fish.
- Fish are cold blooded, so energy is not wasted through keeping the fish warm.
Disadvantages of fish farming?
- Cages can be crowded, infecting can spread fast.
- Pesticides and antibiotics can be used to keep infection down, this can lead to a polluted environment.
- Waste is produced which may need to be removed. this can pollute the water ways.
Salmon farming cycle?
- Newly hatched salmon in fresh water hatchery.
- Controlled light for long periods, speeds up growth, controlled food provided.
- Fish moved to cages in sea loch.
- The Salmon in the cages are fed pellets of concentrated small fish, vaccines, growth hormones and pink coloring.
- The cages keep out other preditors such as otter and pike. They also keep out other fish, reducing competition.
- Salmon grow quickly in cages, Fish are tightly packed 250,000 in one cage. Parasites can become a problem, such as sea lice. Pesticides used.
- Salmon staved for 10 days, empties the gut to increase the storage life of fish.
- Salmon goes to the shop.
Positive effects of using fertilizers?
- Increased yield.
- Kills pests
- faster growth.
Negative effects of using fertilizers?
- Euthophication.
- Issues further down the food chain.