Ecology

Question 1

Ecosystem

Answer 1

A community (the sum of all living things in a habitat) of organisms and its environment (biotic and abiotic components), and the interactions between them

Question 2

Abiotic factor

Answer 2

• The non-living components of an ecosystem
• Affect living things, but are not themselves living
• Affect which organisms can live in an area
• Important in determining the ecosystem of a region

Question 3

Biotic factor

Answer 3

• A living factor within an ecosystem
  □ E.g. animal or plant
• Include the presence or absence of other organisms that can affect an organism

Question 4

Abiotic examples

Answer 4

• Temperature
• Light intensity
• Texture of soil
• pH of soil
• Concentration of significant gases in water or air
• Nutrient availability
• Water availability
• Wind speed
• Wind direction

Question 5

Biotic examples

Answer 5

• Animals
• Plants
• Other organisms of their own species
• Competitors
• Collaborators
• Predators
• Disease causing organisms
• Parasites
• Availability of mates

Question 6

Competition

Answer 6

• When individuals compete for a resources that limits their survival (food, habitat) and reproduction
• Interspecific competition
  □ Competition between two organisms of a different species
  □ E.g. a great white competes with an orca for food
• Intraspecific competition
  □ Competition between two organisms of the same species
  □ E.g. male birds compete for a mate

Question 7

Predator prey/predation

Answer 7

□ One organism (predator) kills another organism (prey) and consumes some or all of it for food
□ Includes
- Animals eating animals (animals preying on other animals)
◊ Lion eating a zebra
- Herbivory
◊ Zebra eating grass
- Plants preying on animals
◊ Venus fly-trap eating flies

Question 8

Disease

Answer 8

• Interaction between a disease-causing organism and a host can affect the biodiversity of an ecosystem
• E.g. Chlamydia (bacteria) can cause disease in koalas, affecting their ability to reproduce

Question 9

Symbiotic relationships

Answer 9

○ A relationship between two or more species that benefits at least one of the species
○ Includes mutualism, parasitism and commensalism

Question 10

Mutualism

Answer 10

• Both species of a relationship benefit and neither is harmed
• E.g. acacia ant and acacia tree

Question 11

Parasitism

Answer 11

• One species (parasite) benefits at the expense of the other (host)
• E.g. fleas on a dog

Question 12

Commensalism

Answer 12

• One species benefits and the other neither benefits or is harmed
• E.g. a bird making a nest on a tree