B4

Question 1

What does an ecosystem consist of?

Answer 1

The living organisms together with the physical conditions in an area.

Question 2

What’s a community?

Answer 2

All organisms (different species) living in a habitat.

Question 3

What’s a habitat?

Answer 3

Place where plants, animals, microorganisms live

Question 4

What’s the defenition of population?

Answer 4

All organisms of 1 species in a habitat

Question 5

What are producers?

Answer 5

Organisms that make thier own food, usually first trophic level.

Question 6

How’s energy transferred between organisms?

Answer 6

• Energy transferred to chlorophyll by light in producers
• CO2 reacts with H20 to make glucose, that stores energy in chemcial bonds
• Some glucose used, rest converts to carbs, fats, protein, this is used to grow. As it grows biomass increases
• Energy transferred to consumers as it gets eaten
• When respiration occurs, energy in food converts to ATP

Question 7

What does the arrow in food chain represent?

Answer 7

Biomass or energy transfer

Question 8

What are biotic factors?

Answer 8

Living factors of an ecosystem

Question 9

What are abiotic factors?

Answer 9

Non living factors (physical) factors of an ecosystem

Question 10

What are the main abiotic factors that affect communities?

Answer 10

• Temperature
• Moisture level
• Light intensity
• Soil pH

Question 11

How does temperature affects communities?

Answer 11

• It greatly affects enzyme controlled metabolic reactions
• Plants develop faster in warmer conditions as metabolism is faster
• Cold-blooded animals (ectotherms) rely on heat from sun for heat, warm blood (endotherms) less affected

Question 12

How does the light intensity affect communities?

Answer 12

• Light required for photosynthesis, more light, more sucess or growth of plant
• Plants evolve fro different light conditions, low light, wider leaves
• if too little light grass can be replaced with fungi, moss that are better able to cope with low light intensity

Question 13

How does moisture level affect communities?

Answer 13

• Lack of water causes death

- Lack of water in plants causes cells to wilt as no water to keep cells turgid, plant falls down

Question 14

How does soil pH affect communities?

Answer 14

-Affects biological activity, some plants grow better in acidic or alkali conditions

Question 15

Why do organisms compete?

Answer 15

• Organisms require materials

- If materials are limited, they are competed for, weaker species end up dying

Question 16

What do plants need to survive?

Answer 16

• Light -Minerals
• Water -Space
• Carbon dioxide

Question 17

What do animals require to survive?

Answer 17

• Food -Shelter
• Water -Territory
• Mates

Question 18

What is something that has a direct impact population?

Answer 18

Competition

Question 19

What’s interdependance?

Answer 19

How organisms in a community depend on each other

Question 20

What are the interactions between organsism known as?

Answer 20

Ecological relationship

Question 21

What are the 3 types of ecological relationships?

Answer 21

• Predation
• Mutualism
• Parasitism

Question 22

Whats predation?

Answer 22

Relationship between predatorand prey species. Prey population directly affects predator population.
predator goes up, prey goes down

Question 23

Why are prey-predator cycles out of phase?

Answer 23

It takes a while for one of each to respond to changes of other

Question 24

Whats mutualism?

Answer 24

Relationship where both organisms benefit

Question 25

Whats an example of mutualsim?

Answer 25

Nodules legume plants, contain nitroogen-fixing bacteria providing plants with nitrates and get sugars in return

Question 26

Whats parasitism?

Answer 26

Relationship where only one organism gains, parsite gains, host organism loses

Question 27

What does a biomass pyramid show?

Answer 27

It shows the flow of biomass through a community

Question 28

Why is a biomass pyramid in the shpae of a pyramid?

Answer 28

Biomass reduces as it cant all be trasferred, so less gets transferred each trophic level

Question 29

Why do scientists calculate dry mass of an organism?

Answer 29

Because waterweight varies between organisms making the average weight not accurate

Question 30

How is the gluose thats made from photosynthesis used?

Answer 30

• Some glucose instantly used in respiration
• Rest of glucose used to make biological molecules, like cellulose
• The biological molecules store energy helping plant grow thus increasing plants biomass

Question 31

Why is not much biomass transferred to the next trophic level?

Answer 31

• Animals use some biomass for respiration, to keep warm and help movement
• Biomass is lost through excretion(sweating, urinating, breathing out)
• Biomass is lost through egestion, getting rid of undigested food as faeces.

Question 32

Why do food chains usually contain max 5 trophic levels?

Answer 32

Somuch biomass is lost at each stage there isn’t enough to support organisms after a certain stage