Ecosystems And Material Cycles

Question 1

What are biotic factors

Answer 1

Any living interaction that affects the distribution of an organism

Question 2

What are abiotic factors

Answer 2

Non living conditions that affect the distribution of an organism

Question 3

Give 2 examples of abiotic factors

Answer 3

pH of soil
Light intensity
Rainfall
Temperature

Question 4

Give examples of biotic factors

Answer 4

Interspecific and intraspecific

Question 5

What is interspecific competition

Answer 5

Competing between species

Eg. Fox eating hare

Question 6

What is intraspecific competition

Answer 6

Competition within species

Eg. Stags fighting for hinds to mate with

Question 7

What is symbiosis

Answer 7

A close relationship between two different species

Question 8

Types of symbiosis

Answer 8

Parasitism and mutualism

Question 9

When does parasitism occur

Answer 9

When an organism (the parasite) benefits from another organism (the host) while causing harm to the host

Question 10

Give an example of parasitism

Answer 10

Elephantitis is caused by an infection with roundworms

Question 11

When does mutualism occur

Answer 11

When two different organisms live together in a relationship that benefits them both. If one is removed, then the other cannot survive

Question 12

Give an example of mutualism

Answer 12

The polyp gets food from the algae when it cannot survive

Question 13

What are three ways ecological degradation can occur

Answer 13

Eutrophication
Introduced species
Fish farming

Question 14

What is eutrophication

Answer 14

A process that is caused by human action (farming and sewage). It literally means the process of making too much food

Question 15

Why is eutrophication bad

Answer 15

Because water draining from fields sprayed with fertiliser may contain lots of nutrients which may run into rivers. Algae and some water plants float on the surface so when eutrophication happens, the water surface is covered with them. Lack of light prevents the plants below the water surface from photosynthesising. The plants die. Bacteria in the water breaks down the dead plants. The bacteria need energy from aerobic respiration to break them down. Fish die as there is not enough oxygen for them

Question 16

How can fish farming be bad

Answer 16

The fish pens encourage the built up of uneaten food and parasites. These in turn pollute the surrounding water and spread to wild populations.

Question 17

How can the introduction of a non-indigenous species reduce biodiversity

Answer 17

They compete with indigenous species for resources (food+shelter). Sometimes they are better at getting these resources and out-compete the indigenous species which decreases in number and eventually die out.

Question 18

Name the process that removes carbon from the air in the carbon cycle

Answer 18

Photosynthesis

Question 19

Name two processes that put carbon back into the air

Answer 19

Respiration and burning

Question 20

Why is the ability to produce potable water important in times of drought

Answer 20

Because we rely on water for drinking

Question 21

Describe the role of nitrogen-fixing bacteria in the nitrogen cycle

Answer 21

Turns atmospheric N2 into ammonia which forms aluminium ions

Question 22

What is crop rotation

Answer 22

Instead of growing the same crop in a field year after year, different crops are grown each year in a cycle.

Question 23

Monocultures

Answer 23

Forest plantations

Question 24

Reforestation

Answer 24

Trees cut down and replanted where they were before

Question 25

Afforestation

Answer 25

Planting of trees which were never there

Question 26

Decomposition

Answer 26

Rotting or decay

Question 27

Combustion

Answer 27

Burning

Question 28

Respiration

Answer 28

Breathing

Question 29

Precipitation

Answer 29

Rain, snow, sleet, hail

Question 30

Condensation

Answer 30

Conversion of vapour gas to liquid

Question 31

Evaporation

Answer 31

Liquid to vapour liquid