ECOLOGY

Question 1

What is a decomposer?

BREAK DOWN
DIGEST
USE NUTRIENTS

Answer 1

• a group of microorganisms (including bacteria and fungi) that break down waste and dead organisms (including animals and plants)
• the bacteria and fungi then digest everything - dead animals, plants plus their waste
• they use some of the nutrients to grow and reproduce and release carbon dioxide, water, and mineral ions as waste products
• decomposers return mineral ions (including nitrates to the soil)
• plants take them up through their roots and use them to make proteins
• decay returns carbon to the atmosphere as carbon dioxide that can be used by producers in photosynthesis
• decomposers also clean up the environment, removing the bodies of all the dead organisms

Question 2

Describe the main events in the water cycle and describe what happens at each stage

Answer 2

precipitation - as water droplets in clouds get heavier, they fall as rain, slow or sleet
percolation - water trickles through gaps in solids and rocks
transpiration and respiration - loss of water vapour from plants and animals directly to the atmosphere –> water vapour
surface run off
water goes into the oceans –> evaporates –> water vapour
condensation - as air rises, it cools. water vapour condenses back into liquid water droplets producing clouds
cooling
-precipitation