B4.1: Ecosystems

Question 1

What is an ecosystem?

Answer 1

a community of living organisms and physical conditions in a particular area

Question 2

What is a community?

Answer 2

Organisms within the ecosystem

Question 3

What is a habitat?

Answer 3

The area where organisms live

Question 4

What is a population?

Answer 4

The total number of organisms of each species

Question 5

Which 3 groups are organisms divided into in a community?

Answer 5

Producers
Consumers
Decomposers

Question 6

What are producers?

Answer 6

Organisms that make their own food by photosynthesis
Plants
Algae

Question 7

What are consumers?

Answer 7

Organisms that cannot make their own food.
Have to eat other organisms to gain energy
All animals are consumers

Question 8

What are decomposers?

Answer 8

Special group of composers
Gain energy by feeding on dead or decaying matter

Question 9

What is biomass?

Answer 9

Mass of living material present

Question 10

What happens to biomass as an organism grows?

Answer 10

Increases in biomass

Question 11

What does a food chain display?

Answer 11

What an organism eats

Question 12

What do arrows in a food chain display?

Answer 12

Transfer of biomass from one organism to another

Question 13

What is a trophic level?

Answer 13

Each step in a food chain

Question 14

What does a food chain always begin with?

Answer 14

Producer - grass/plants

Question 15

What is a prey organism?

Answer 15

Eaten by another organism

Question 16

What is a predator organism?

Answer 16

It eats another organism

Question 17

What type of organism may you find at trophic level 1?

Answer 17

Producer

Question 18

What type of organism may you find at trophic level 2?

Answer 18

Primary consumer

Question 19

What type of organism may you find at trophic level 3?

Answer 19

Secondary consumer

Question 20

What type of organism may you find at trophic level 4?

Answer 20

Tertiary consumer

Question 21

What are biotic factors?

Answer 21

Living factors

Question 22

What are abiotic factors?

Answer 22

Non-living factors
Rainfall, temp of ecosystem

Question 23

How do light intensity affect communities?

Answer 23

Greater the light intensity, the greater te success of plants because light is needed to maximise photosynthesis

Question 24

How do temperatures affect communities?

Answer 24

Effect on enzymes that control metabolic reactions
Plants develop faster in warmer temperatures
Plants and animals have evolved to grow healthily at optimum temps

Question 25

How do moisture levels affect communities?

Answer 25

Overwatering plants, waterlogged soils, little oxygen Other plants like pitcher plants, (that grow in bogs) would need high moisture levels

Question 26

How does soil pH affect communities?

Answer 26

Affects biological activity in soil Some plants develop better in acidic soils (pH below 7) Some plants develop better in alkalinic soils (pH above 7)

Question 27

What is competition within an ecosystem?

Answer 27

Each of the organisms trying to survive in the ecosystem

Question 28

What MUST animals get access to in order for them to survive?

Answer 28

Food Water Space

Question 29

What MAY animals get access to in order for them to survive?

Answer 29

Sunlight, photosynthesis Mineral salts Water Space

Question 30

What is interdependance?

Answer 30

When scientists study how different organisms depend on each other within a community

Question 31

What are ecological relationships?

Answer 31

Interactions between organisms

Question 32

What are the 3 main types of ecological relationships?

Answer 32

Predation Mutualism Parasitism

Question 33

What is predation?

Answer 33

Name given to the relationship between predators and prey Size of predator population directly affects the prey population

Question 34

What is mutualism?

Answer 34

Both organisms benefit from the relationship

Question 35

What is parasitism?

Answer 35

Only one organism gains whereas the host suffers

Question 36

What do food chains show?

Answer 36

The flow of biomass through a community BUT They dont show the number of organisms involved or size of biomass transferred

Question 37

What are the food chain diagrams like?

Answer 37

Pyramid shape going from one trophic level to the next

Question 38

How can you calculate biomass?

Answer 38

Measure average mass of each of the organisms and multiply it by the number of organisms present

Question 39

What is the efficiency of biomass transfer like?

Answer 39

Usually only 10% is transferred between trophic levels Remaining 90% is used by organisms in life processes

Question 40

When can biomass be lost?

Answer 40

Not all of the organism is eaten: bones/roots not consumed Some biomass used in respiration Some parts of an organism might not be digestible Waste products lost through excretion, urine

Question 41

What is the efficiency of biomass transfer?

Answer 41

(Biomass available after transfer/ biomass available before transfer) x 100%

Question 42

How can animals put nitrogen back into the soil?

Answer 42

Urine Faeces

Question 43

What is the flow of nitrogen like in the nitrogen cycle?

Answer 43

When a plant is eaten, nitrogen compounds are passed onto an animal. When a plant is eaten and then the plants and animals die, compounds are released and broken down, and released back into soil as ammonia.

Question 44

How can water determine habitats?

Answer 44

Polar bears rely on ocean ice Frogs require water to reproduce Sharks can only survive when being submerged in water

Question 45

How does the water cycle move water?

Answer 45

Moves water and nutrients through the atmosphere, soil, rivers, lakes and oceans. By doing so, it brings fresh water to people, animals and plants

Question 46

By which processes does carbon cycle through the atmosphere?

Answer 46

Photosynthesis Respiration Combustion

Question 47

In carbon cycling, how does the carbon start and end in photosynthesis?

Answer 47

Starts as Carbon dioxide Ends as Glucose

Question 48

In carbon cycling, how does the carbon start and end in respiration?

Answer 48

Starts as glucose Ends as carbon dioxide

Question 49

In carbon cycling, how does the carbon start and end in combustion?

Answer 49

Starts as fuel - methane Ends as carbon dioxide

Question 50

How does carbon enter the atmosphere?

Answer 50

Enters as carbon dioxide from respiration and combustion

Question 51

Who absorb carbon dioxide?

Answer 51

Absorbed by producers to make glucose in photosynthesis

Question 52

What do decomposers break down?

Answer 52

Dead mattter Faeces Urine

Question 53

What are organisms that feed on dead matter called?

Answer 53

Saprophytes

Question 54

What are detritivores?

Answer 54

Smal animals Speed up decomposition by shredding organic material into very small pieces Creates a larger surface area for decomposers to work on

Question 55

What are examples of detritivores and what do they break down?

Answer 55

Earthworm: leaves Woodlouse: wood Maggot: animal material

Question 56

What is the formula for the rate of decay?

Answer 56

Change in mass (g) / time (days)

Question 57

How does temp affect the rate of decomposition?

Answer 57

Temp: high temps prevent decomposition (denature enzymes) but low temps slow it down (slow rate of enzymes)

Question 58

How does oxygen availability affect the rate of decomposition?

Answer 58

Lack of oxygen will prevent decay Oxygen is needed for microorganisms aerobic respiration Without oxygen they will die Very few organisms can still decompose using anaerobic respiration

Question 59

How does water availability affect the rate of decomposition?

Answer 59

Lack of water will prevent decay Water is needed to support reactions inside microorganisms Decomposers need water to digest