22- Ecosystem

Question 1

What are food chains?

Answer 1

diagram that shows how energy is transferred

Question 2

what are food webs

Answer 2

network of interconnected food chains

Question 3

what is the pyramid of numbers?

Answer 3

Pyramid showing biomass of trophic levels

Question 4

what is a trophic level?

Answer 4

position of an organism in a food web or food chain

Question 5

how is energy transferred along a food chain.

Answer 5

1. Plant use energy form sunlight to make chemical energy, 90% lost
2. Herbivores use 90% of the energy from the plant from the plant for staying alive
3. Carnivores use 90% of the energy from the herbivores to stay alive
4. only 10% of the energy becomes bio mass

Question 6

how do humans impact food webs?

Answer 6

over-harvesting: when deaths > births in a species

Question 7

how is N2 in the air turned into mineral ions

Answer 7

1. Nitrogen fixing bacteria: nitrogen fixing bacteria in the soil in legume roots
2. Lightning

Question 8

what are the 4 micro organisms involved in the nitrogen cycle

Answer 8

1. Decomposers: break down proteins into ammonium ions.
2. Nitrifying bacteria: use ammonium ions to create nitrites then nitrates
3. Denitrifying bacteria: turn nitrates into N2
4. Nitrogen fixing bacteria: turn nN2 into nitrates

Question 9

define population, community and ecosystem

Answer 9

1. Population: group of organisms of one species living in the same area at the same time.
2. Community: All the populations of different species living in an ecosystem
3. Ecosystem: A unit containing the community of organisms and its environment, interacting together