Use of Biological Resources Flashcards
How can ideal photosynthesis conditions be replicated?
Glasshouses (big greenhouses) or Polytunnels (large tube-like polythene structures)
What are the ideal conditions created by glasshouses/polytunnels?
Enclosed - Free from pests and diseases.
Controlled water supply.
Artificial light can be used in the night for 24 hour growth.
Traps the sun’s heat to keep plants warm.
Paraffin-heaters increase CO2 levels.
What is a plant fertiliser used for?
Fertilisers replace or surplus minerals.
The minerals are such as nitrogen, potassium and phosphorus.
How does pest control change crop yields?
If fewer plants are damaged or destroyed then more crops survive, increasing the crop yield.
What are pesticides?
They are a form of chemical pest control. They are often poisonous to human’s so they must be used carefully to make sure there is a safe level of pesticides in the food.
What is Biological Control? (In relation to pest control)
It is reducing pest numbers through the use of other organisms. Through encouraging wild organisms or adding new ones.
Which is a more suitable form of pest control, pesticides or biological control?
Biological control has a longer lasting effect than pesticides, and are less harmful to humans and wildlife. However only when done properly, eg. Cane toads in Australia.
What is fermentation?
Fermentation is when microorganisms break sugars down to release energy, usually by anaerobic respiration.
What is just basically fermented milk?
Yoghurt
How is Yoghurt made?
1) The equipment is sterilised to kill unwanted microorganisms.
2) The milk is pasteurised (heated to 72C for 15 seconds) - to kill harmful microorganisms. Then left to cool.
3) Lactobacillus bacteria are added, and the mixture is incubated (heated to 40C) in a fermenter.
4) The bacteria ferment the lactose sugar in the milk to form lactic acid, causing the milk to clot and solidiy into yoghurt.
5) Flavours and colouring’s are added.
What is formed in the aerobic respiration of yeast?
Carbon Dioxide and Water
How is bread made?
A dough is made from mixing yeast, flour, water and sugar. The dough is left in a warm place to rise. The yeast respires and the dough has CO2 which expands the bread. When baked the yeast continuous to respire until it dies and the bread stops rising.
Summarise Selective Breeding:
Mating the best plants or animals with each other to produce the best offspring possible.
Give examples of a best feature that might be selectively bred for.
- Size of meat/grains.
- Maximum yield of milk/eggs
- Speed, Temperament, Fertility, Mothering Skills, etc.
- Attractive flowers, Good smells, etc.
What is the basic process for Selective breeding?
1) From your existing stock, select the ones with the best characteristics.
2) Breed them with each other.
3) Select the best offspring, Breed them together.
4) Continuing the process over many generations, and the desirable traits get stronger and stronger.
