B 12, 13

Question 1

What are the two ways toxins build up in organisms?

Answer 1

Bioaccumulation - toxins enter the food web by building up in individual organisms

biomagnification - toxins are passed from one trophic level to the next (and thereby increase in concentration)

Question 2

Why are only some of the carbon taken in by animals passed to the carbon compounds in dead organisms?

Answer 2

Animals respire and release carbon dioxide

+ carbon is lost by excretion

Question 3

what is the process called?

carbon compounds in plants –> carbon compounds in animals

Answer 3

feeding, nutrition

Question 4

What are the four effects of removing rainforests?

Answer 4

loss of soil/erosion
loss of habiat - extinction of species
flooding
increase in CO2 in the atmosphere

Question 5

Why do stonefly nymphs die in a river polluted with sewage?

Answer 5

it causes the decomposers to feed on it by respiring and using up oxygen, and making it unable for aerobic respiration to happen –> death

Question 6

why do stonefly nymphs die in a river polluted with chemical waste?

Answer 6

chemical waste is toxic and it can bioacculumate, eventually becoming fatal enough, killing it.

Question 7

What are ways that waste energy during transfer between trophic levels

Answer 7

respiration in order to create heat
not all prey are eaten
not all prey are digested, the waste products are egested

Question 8

What is an ecosystem

Answer 8

A unit containing all of the organisms and their environment, interacting together in a given area

Question 9

What is a foodweb

Answer 9

A network of interconncected food chains

Question 10

what is a food chain?

Answer 10

A method of showing the transfer of energy from one organism to the next, beginning with a producer

Question 11

what is a producer?

Answer 11

organism that makes its own organic nutrients

Question 12

what are decomposers

Answer 12

organisms that get its energy from dead or waste matter

Question 13

What are the five components in the carbon cycle

Answer 13

carbon dioxide in the atmosphere, fossil fuels, carbon compounds in dead organisms, carbon compounds in animals, carbon compounds in plants

Question 14

name to processes of the carbon cycle (7)
and what other things effect the carbon cycle

Answer 14

combustion, respiration, nutrition/feeding, fossilisation, photosynthesis, decomposition, excretion and egestion.

human activity, deforestation

Question 15

how do fossil fuels form

Answer 15

millions of years, a lot of pressure, no decomposers,

Question 16

why forestation?

Answer 16

building, plantation, animal farming

Question 17

What is eutrophication?

and explain the steps

Answer 17

The sudden increase in the nutrient content of a a lake or river

1. fertilisers are washed into a lake/river
2. algae feed on them and drastically increas population
3. algal blooms block sunlight resulting in, decrease in plant population
4. bacteria feed on the dead plants and use up oxygen
5. organisms that require aerobic respiration have difficulties surviving.