Topic 9

Question 1

Population

Answer 1

A group of organisms of the same species living in the same place at the same time

Question 2

A community

Answer 2

All the populations living in the same area at the same time

Question 3

A habitat

Answer 3

Place where an organism lives

Question 4

Ecosystem

Answer 4

All the biotic factors and abiotic factors that interact within one area at one time

Question 5

Biotic factors

Answer 5

All living components such as plants and animals

Question 6

Abiotic factors

Answer 6

All non living factors such as mineral ions, water availability and light intensity

Question 7

Interdependence

Answer 7

If one species is removed it will affect the whole community

Question 8

Paristic relationship

Answer 8

Parasite gains resources but host does not

Question 9

Mutalsitic relationships

Answer 9

Both organisms benefit in some way

Question 10

Biodiversity

Answer 10

The range of variety of different species of organisms within a given area

Question 11

Important of biodiversity

Answer 11

High biodiversity ensures the stability of ecosystems by reducing the dependence of one species on another

Question 12

Distribution

Answer 12

How a species is spread out in an ecosystem

Question 13

How are quadrants laid

Answer 13

Randomly to prevent bias

Question 14

The carbon cycle

Answer 14

Carbon is taken out of the atoms sphere in the form of co2 by plants
It is passed onto animals by feeding
It’s returned to the atomosphere as a result of reputation
If animals and plants die in conditions were decomposing microorganisms are not present the carbon in their bodies can be converted into fossil fuels
Fossil fuels are burnt and carbon is released

Question 15

The importance of the carbon cycle

Answer 15

To maintain the correct balance between stores in order to sustain life

Question 16

What does the nitrogen cycle show

Answer 16

How nitrogen is recycled in ecosystems

Question 17

How much of the atomesphere is nitrogen

Answer 17

78%

Question 18

Nitrogen fixation

Answer 18

Atomespheric nitrogen gas is converted into nitrogen containing compounds such as ammonia form ions that can be used in plants
This is carried out by nitrogen fixing bacteria that are found free living in soil and in the root nodules of certain legumes - it takes N2 gas and changes it into nitrates in the soil

Question 19

Ammonification

Answer 19

Nitrogen compounds in waste products and dead organisms are converted into ammonia by saprobiants
This ammonia form ammonium ions in the soil

Question 20

Nitrification

Answer 20

The ammonium ions are converted by nitrifying bacteria into nitrates which can be used by plants

Question 21

Denitrification

Answer 21

Denitrifying bacteria use nitrates in the soil during respiration
The process produces nitrogen gas which returns to the atmosphere
Occurs in anaerobic conditions

Question 22

Benefits of fish farms

Answer 22

Raise large numbers of fish in a small space
Maximise yields

Question 23

The effect of fish farms on biodiversity

Answer 23

Predators may be attracted and get caught in nets
Diseases can spread quickly
Eutrophication can occur