Cycles within ecosystems

Question 1

What organism is involved in decomposition?

Answer 1

decomposers

Question 1

What organism is involved in nitrogen fixation?

Answer 1

nitrogen fixing bacteria

Question 2

What organism is involved in nitrification?

Answer 2

nitrifying bacteria

Question 3

What organism is involved in denitrification?

Answer 3

denitrifying bacteria

Question 4

Describe the process of decomposition

Answer 4

conversion of waste products into ammonia

Question 5

Describe the process of nitrogen fixation

Answer 5

conversion of nitrogen gas into ammonia

Question 6

Describe the process of nitrification

Answer 6

oxidation of ammonia into nitrites then nitrates

Question 7

Describe the process of denitrification

Answer 7

nitrates are used as energy
nitrogen gas released

Question 8

Explain why farmers would grow pea plants and then plough the roots through their fields

Answer 8

pea plants are leguminous so have root nodules which contain nitrogen fixing bacteria
bacteria decompose
increase soil fertility due to ammonia that can -> nitrates

Question 9

Which compounds in living things contain nitrogen?

Answer 9

protein and nucleic acid

Question 10

Which compounds in living things contain carbon?

Answer 10

carbohydrates, lipids, protein and nucleic acid

Question 11

Describe the process of saprotrophic feeding

Answer 11

bacteria and fungi release enzymes to break down an organism or waste products

Question 12

What is a community?

Answer 12

all populations of different species living together in a particular place at a particular time

Question 13

What are abiotic factors?

Answer 13

non-living parts of an ecosystem

Question 14

What are biotic factors

Answer 14

living components of an ecosystem

Question 15

What is biodiversity?

Answer 15

variety of living organisms in an ecosystem

Question 16

What is distribution?

Answer 16

spread of living organisms

Question 17

What is an ecosystem?

Answer 17

community of organisms and non living components of a particular area and how they interact with one another

Question 18

What is a habitat?

Answer 18

place in an ecosystem when an organism lives

Question 19

What is population?

Answer 19

all the organisms of the same species living with one another in a habitat at any one time

Question 20

What are decomposers?

Answer 20

organisms that release enzymes which speed up breakdown of dead material

Question 21

What are energy transfers?

Answer 21

the flow of energy from one trophic level to the next

Question 22

What does a food chain show?

Answer 22

feeding relationships between organims

Question 23

What is a food web?

Answer 23

network of food chains

Question 24

What is a primary consumer?

Answer 24

herbivores consume producers

Question 25

What are producers?

Answer 25

photosynthetic organisms that provide biomass for all organisms in food chain

Question 26

What is a pyramid of biomass?

Answer 26

pyramid with each layer representing amount of mass of living material at each trophic level of food chain

Question 27

What is a pyramid of number?

Answer 27

pyramid showing numbers of each organism at each trophic level

Question 28

What is a quadrat?

Answer 28

square grid

Question 29

What are quaternary consumers?

Answer 29

carnivores consume tertiary consumers

Question 30

What are secondary consumers?

Answer 30

carnivores consume primary consumers

Question 31

What are tertiary consumers?

Answer 31

carnivores consume secondary consumers

Question 32

What is an apex predator?

Answer 32

organism not consumed by another

Question 33

What is a trophic level?

Answer 33

position of an organism in a food chain

Question 34

Why is it better to draw a pyramid of biomass rather than a pyramid of numbers?

Answer 34

pyramid of numbers are variable, pyramid of biomass always look the same

Question 35

Describe how we can use a quadrat to measure population

Answer 35

estimate % cover of species OR count number of particular species

Question 36

Describe how we can use a quadrat to measure diversity

Answer 36

count number of different species

Question 37

Give examples of abiotic factors

Answer 37

temperature, light intensity, moisture, soil pH, CO2 and O2 levels

Question 38

Give examples of biotic factors

Answer 38

food availability, pathogens, predation and competition

Question 39

What organisms are decomposers?

Answer 39

bacteria and fungi

Question 40

What happens to the amount of energy transferred as you move up the food levels?

Answer 40

decreases

Question 41

Why does the amount of energy transferred decrease as you move up the food levels?

Answer 41

energy used respiration/movement lost in excretory products

Question 42

What do the arrows represent in a food chain?

Answer 42

flow of energy

Question 43

Why are food webs better than food chains?

Answer 43

more realistic animals feed on one or more organism

Question 44

What is a quadrat used for?

Answer 44

sample populations abundance distribution of organisms

Question 45

How much energy is transferred between trophic levels?

Answer 45

only 10% transferred from one to the next

Question 46

Where are nitrogen fixing bacteria found?

Answer 46

root nodules of legumes soil

Question 47

Give examples of decomposers

Answer 47

fungi bacteria