B4.1

Question 1

What are the organisms in an ecosystem called

Answer 1

Community

Question 2

Population

Answer 2

The total number of organisms of each species

Question 3

Types of organism

Answer 3

Producers
Consumers
Decomposers

Question 4

Producers

Answer 4

Make their own food by photosynthesis

- plants/ algae

Question 5

Consumers

Answer 5

Can’t make their own food

Question 6

Decomposers

Answer 6

Type of consumer. Gain energy by feeding on dead/ decaying material

Question 7

How is energy transferred between organisms

Answer 7

• energy from transferred by light to chlorophyll in producers
• produces glucose stored energy in bonds
• glucose converted to fats/ proteins/ carbs
• consumer eats producer - when respires the energy stored in the bonds is transferred to atp

Question 8

What’s at the start of all food chains

Answer 8

A producer

Question 9

What are the tropic levels

Answer 9

1 - producer
2 - primary consumer - herbivore/ omnivore
3- second consumer - carnivore/ omnivore

Question 10

What are abiotic factors

Answer 10

Non - living factors

- rainfall/ temperature

Question 11

What are biotic factors

Answer 11

Living factors

-beech trees/ animals

Question 12

How does light intensity effect communities

Answer 12

• required for photosynthesis

- evolved to grow - large SA

Question 13

How does temperature effect communities

Answer 13

• effect in enzymes that control metabolic reactions
• plants develop faster in warmer conditions - higher metabolism
• cold - blooded (lizards) require sun to warm them

Question 14

How do moisture levels effect communities

Answer 14

• lack of water - death
• plants - flaccid - Wilt
• overwatering - no oxygen/ no respiration - death

Question 15

How does soil communities effect pH

Answer 15

• some plants grow at different pH levels
• acidic -ferns
• alkaline - cucumbers

Question 16

What do plants need to survive

Answer 16

• light, water, carbon dioxide, minerals and space

Question 17

What do animals need to survive

Answer 17

• food water breeding partners space and shelter

Question 18

Interdependence

Answer 18

Refers to how all organism rely on each other to survive

Question 19

What is predation

Answer 19

• between predator and prey

Question 20

What is mutualism

Answer 20

• both organism benefit from the relationship

Question 21

What is paratism

Answer 21

• only one organism gains (the parasite)

- host suffers

Question 22

How to calculate biomass

Answer 22

Average mass of each organism x number of organisms present

Question 23

Why do they take the dry mass of an organism

Answer 23

• water content varies

Question 24

How much chemical energy do consumers at each trophic level convert

Answer 24

10%

Question 25

How is biomass lost

Answer 25

- not all eaten - eg. Bones - used in respiration - indigestible parts - egestion (removed from body as faeces) - extraction

Question 26

How to calculate the efficiency of biomass transfer

Answer 26

Energy after/ energy before

Question 27

What is nutrient cycling

Answer 27

How materials are passed between biotic and abiotic factors

Question 28

What are the three types of bacteria in the nitrogen cycle

Answer 28

- nitrifying bacteria (nitrites - nitrates) - denitrifying bacteria (nitrates - nitrites) - nitrogen - foxing bacteria (root nodules)

Question 29

Basic nitrogen cycle

Answer 29

- Nitrogen from air transfers into plants into plants by nitrogen - fixing bacteria/lightning - plants either eaten by animals ( excretes ammonia) or decomposes (ammonia) - nitrifying bacteria turns ammonia into nitrites and then nitrates - denitrifying break down nitrates and release into the air

Question 30

Water cycle

Answer 30

-precipitation - percolation - through gaps in soil - surface run off (End up in ocean) - ocean evaporates into water vapour - transpiration - water vapour - water vapour condenses

Question 31

Basic carbon cycle

Answer 31

- plants photosynthesise - take in co2 - plants decompose or animals eat and then decompose - carbon in decaying waste (Become fossil fuels or respire away) - fossil fuels burnt - releases co2 (Plants and animals respire - release co2 into atmosphere)

Question 32

How is carbon dioxide removed from atmosphere

Answer 32

- photosynthesis

Question 33

How is carbon released into the atmosphere

Answer 33

- respiration - decomposition - release co2 as they respire - burning fossil fuels

Question 34

How do carbon levels vary throughout the day

Answer 34

- photosynthesis only takes place in light/ daytime - less co2 in the day - respiration carried out all day - more co2 at night cause there’s nothing to absorb it

Question 35

Decomposers

Answer 35

Break down animal waste

Question 36

Detrivores

Answer 36

Shredd organic material into very small pieces - larger SA - digest internally and absorb nutrients - speeds up decomposition

Question 37

How do decomposers release nutrients

Answer 37

- secrete enzymes to break down DOM and absorb soluble nutrients back into their body

Question 38

What factors effect the rate of decomposition

Answer 38

- warm temperatures - denaturing of enzymes - death - cold temp - slow rate of decomposition - moist environments - lack of water slows down reactions in microorganisms - aerobic conditions - oxygen is needed for microorganisms to respire

Question 39

How to calculate rate of decay

Answer 39

Change in mass/ time