Flashcards in 184.108.40.206 - Energy and Ecosystems (Agricultural Farming) Deck (13)
Describe two ways that farming practises can increase the amount of energy available for human consumption.
1. Reduce the energy lost to other organisms e.g pest control.
Reduce the energy lost through respiration e.g restrict movement, control temp.
What are insecticides used for?
To kill insect pests that eat and damage crops.
What are herbicides used for?
To kill weeds to remove direct competition for sunlight.
How do biological agents increase crop yield?
They reduce the number of pests, so crops lose less energy and biomass.
What type of biological agents can be used?
Parasites to either kill the insect or reduce it's ability to function or
Pathogenic bacteria and viruses
What is an integrated system ?
A system of using both chemical and biological methods to reduce pests.
What ethical issues might arise from keeping animals in pens?
It may cause animals pain, distress and restrict their natural behaviours.
Why are intensively reared animals kept indoors?
To control the environmental temperature so less energy is wasted by generating body heat.
Keeping cattle indoors, in barns, leads to a higher efficiency of energy transfer.
Less energy lost as heat / in maintaining body
temperature / in movement
Explain 3 advantages for a farmer of removing hedgerows.
1. source of pests / animals, this effect on crop;
2. source of weeds / no longer taking nutrients, hence competition / reduced yield;
3. creation of larger fields / leaving room, hence more efficient use of machinery / grow more crops;
Apart from providing a habitat for predators of crop pests, give 3 biological benefits of replanting hedgerows.
2.source of food for animals;
3. habitat / nest for animals;
Give one reason why not all the light energy falling on the producers is used in photosynthesis.
transmission / reflected / misses chlorophyll / chloroplasts / wrong wavelength;