6.3.1 Ecosystems

Question 1

Definition of an ecosystem

Answer 1

All the living organisms that interact with one another in a defined area, and physical factors present in that region
Vary in size
Dynamic (constantly changing)

Question 2

Examples of ecosystems

Answer 2

Rock pool
Oak tree
Playing field
Stretch of river

Question 3

Biotic factors that affect ecosystems

Answer 3

Presence of species, size of their populations
Competition within or between populations:
- for food
- for space
- for breeding partners

Question 4

Abiotic factors that affect ecosystems

Answer 4

Temperature:
- plants and ectotherms
- changing seasons can trigger migration and hibernation
- trigger leaf-fall, dormancy, flowering
Light availability:
- for plants, can adapt to certain conditions
Water availability:
- plants, can adapt
- plants wilt in lack of water
Oxygen availability
Soil factors: clay/loam/sandy

Question 5

What is a trophic level

Answer 5

Stage in a food chain

Question 6

What do food webs and chains show

Answer 6

Transfer of biomass through organisms in an ecosystem

Question 7

Food chain trophic levels

Answer 7

First: producer
All the rest: consumers
(Primary, secondary, tertiary, quaternary)
Decomposers

Question 8

Biomass definition

Answer 8

Mass of living material present in a place or organism