Ecosystems and Interactions

Question 1

define a population

Answer 1

all the organisms of one species in a habitat

Question 2

define a community

Answer 2

all the organisms of different species living in a habitat

Question 3

define an ecosystem

Answer 3

a community of organisms along with all the non living conditions

Question 4

what is interdependent ?

Answer 4

when organisms depend on each other for food and shelter in order to survive

Question 5

what is mutualism ?

Answer 5

relationship between two organisms from which both organisms benefit

Question 6

what is parasites?

Answer 6

they take what they need to survive and don’t benefit the other organism

Question 7

what does abiotic mean?

Answer 7

non living

Question 8

examples of abiotic factors

Answer 8

temperature
amount of water
light intensity
levels of pollutants

Question 9

what does biotic mean?

Answer 9

living

Question 10

example of biotic factors

Answer 10

competition

predation

Question 11

what is biodiversity?

Answer 11

variety of living organisms in an ecosystem

Question 12

what causes eutrophication?

Answer 12

when nitrate is used as fertiliser and flows into rivers

Question 13

what is the effect of eutrophication?

Answer 13

death of many species reducing biodiversity

Question 14

how does eutrophication work?

Answer 14

• fertilisers enter the rivers
• algae grows fast and blocks light
• plants can photosynthesise and start to decompose
• micro organisms increase as more food

Question 15

what are non indigenous species?

Answer 15

one the doesn’t normally occur in an area

Question 16

disadvantages of non indigenous species

Answer 16

bring new diseases
reduces biodiversity
kill indigenous species as beat them for food

Question 17

Give ways fish farms can reduce biodiversity

Answer 17

• farmed fish escape into the wild and cause problems for indigenous species
• predators attracted to net and die
• parasites get out of farm and infect wild animals
• waste can leak into open water and cause eutrophication

Question 18

what is reforestation?

Answer 18

when land where a forest previously stood is replanted to form a new forest

Question 19

Deforestation

Answer 19

removes trees reducing biodiversity

Question 20

why do forests have a high biodiversity?

Answer 20

because they contain a wide variety of tress and plants to provide food and shelter

Question 21

what are examples of conservation schemes?

Answer 21

protecting a species habitat
protecting species in safe areas
seed banks to store and give seeds to endangered plants

Question 22

Benefits of maintaining biodiversity

Answer 22

• protecting the human food supply
• ensuring minimal damage to food chains
• providing future medicines
• cultural species
• providing new jobs

Question 23

what does ecotourism do?

Answer 23

helps bring money into biodiversity areas w he re conservation work is taking place

Question 24

what are the four steps of the carob cycle?

Answer 24

photosynthesis
respiration
combustion
decomposition

Question 25

What are the steps of the water cycle?

Answer 25

• energy from sun makes water evaporate into vapour
• warm vapour is carried upwards
• it cools and condenses to form clouds
• precipitation falls from the clouds
• provides water for plants and drains into the sea

Question 26

what is desalination?

Answer 26

removes salts from salt water

Question 27

what causes droughts?

Answer 27

when there isn’t enough precipitation

Question 28

what is thermal desalination and how does it work?

Answer 28

water is boiled in a enclosed vessel so water evaporates
the steam rises and the salt stays at the bottom
condenses into pure water

Question 29

what does reverse osmosis do?

Answer 29

removes impurities

Question 30

how do farmers increase the amount of nitrate in the soil?

Answer 30

crop rotation - different crops grown in a cycle

Fertilisers

Question 31

Disadvantage of fertilisers

Answer 31

artificial ones can be expensive

Question 32

what is nitrogen fixation?

Answer 32

process of turning nitrogen from the air into nitrogen containing ions in the soil

Question 33

what are the two ways nitrogen fixation happen?

Answer 33

lightening

nitrogen fixing bacteria

Question 34

Decomposers

Answer 34

decompose proteins and urea to turn them into ammonia

Question 35

Nitrifying bacteria

Answer 35

turns ammoni in decaying matter into nitrites and the nitrates

Question 36

Nitrogen fixing bacteria

Answer 36

turn atmospheric N2 into ammonia which forms ammonium ions

Question 37

Denitrifying bacteria

Answer 37

turns nitrates back into N2

Question 38

how much nitrogen gas is in the atmosphere?

Answer 38

78%