B3.3

Question 1

What is an ecosystem

Answer 1

All of the living organisms plus non living things such as soil and air found in one place

Question 2

What is habitat

Answer 2

The area in which an organism lives

Question 3

What is population

Answer 3

Number of one species living in a habitat or community

Question 4

What is community

Answer 4

All of the organism of all the species that live together in a habitat

Question 5

What factors affect how well an organism survives

Answer 5

Competition for food
Predation
Space
Water
Light
Shelter
Mates
Pollinators
Seed dispersers

Question 6

What do food webs show

Answer 6

The transfer of energy between organisms

Question 7

What is each level in a food web called

Answer 7

A trophic level

Question 8

What do the two pyramids show and which is better

Answer 8

Pyramids of biomass show the mass of all organisms in a trophic level, whereas pyramid of numbers shows how many there are and doesn’t take the size of the organism into account. Pyramids of biomass are more accurate since it shows you the size

Question 9

Is wet mass as accurate as dry mass and why

Answer 9

No wet mass changes it’s mass too much on a daily and seasonal basis

Question 10

Where is energy lost

Answer 10

Heat loss through cellular respiration
Egestion
Excretion

Therefore energy transfer is not efficient

Question 11

How do you calculate percentage efficiency

Answer 11

(Average energy in higher trophic level/average energy in lower trophic level) *100= percentage efficiency

Question 12

What does energy transfer explain

Answer 12

The shape of a pyramid of biomass

Question 13

What is decomposition

Answer 13

The process catalysed by enzymes released by microorganisms (bacteria and fungi)

Question 14

What is decomposition affected by

Answer 14

Temperature- affects enzymes and rate of reaction
Water- microorganisms need water to survive
Oxygen- needed for oxygen to respite

Question 15

What can methane be used for

Answer 15

Cooking and heating

Question 16

How can decomposition be improved on a landfill site

Answer 16

Good oxygen and constant temperature

Question 17

What do recycling and reusing do

Answer 17

Reduce waste going to landfill sites

Question 18

Why is methane produced in landfill sites

Answer 18

As landfill sites are often oxygen deficient there is an increase in anaerobic decomposition which produces methane which contribute lyes to global warming

Question 19

What happens to faeces and dead organisms

Answer 19

Detrivoree break down large bits into smaller bits ie worms and wood lice
Micro organisms decompose it ie bacteria and fungi

Question 20

What is the dry mass of organisms called

Answer 20

Biomass

Question 21

What is the unit of energy measurement

Answer 21

Joules

Question 22

What is the process when undigested food leaves the body

Answer 22

Egestion

Question 23

What do you call an animal that eats dead things

Answer 23

Detritivore

Question 24

What is the carbon cycle

Answer 24

The process in which carbon enters the food chain in photosynthesis and returns to the air when plants and animals respite

Question 25

What do decomposes like bacteria and fungi release in respiration

Answer 25

Carbon dioxide

Question 26

What happens to some plants and animals after millions of years

Answer 26

They form fossil fuels like coal oil and gas and release carbon dioxide

Question 27

What does feeding pass along the food chain

Answer 27

Carbon dioxide pesticides and energy

Question 28

How do soil and bacteria release carbon dioxide into the air

Answer 28

When they act as decomposers