B7- Ecology

Question 1

What is an ecosystem?

Answer 1

The interaction of a community of biotic (living) with abiotic (non-living) parts of the environment.

Question 2

What four things do plants compete for?

Answer 2

• space
• water
• light intensity
• mineral ions

Question 3

What is a community?

Answer 3

A group of animals and/or plants of a different species

Question 4

What is a population?

Answer 4

A group of animals or plants of the same species

Question 5

What three things do animals complete for?

Answer 5

• Mates
• Food
• territory

Question 6

Give two examples of producers.

Answer 6

• Algae

* Plants

Question 7

Give an example of interdependence in a community.

Answer 7

Species depending on each other for:
•Food
•Shelter
•Pollination 
•seed dispersal

Question 8

What is a stable community?

Answer 8

Population size that remains fairly constant

Question 9

Name the primary consumer in this food chain:

Grass-> Rabbit-> Fox-> Eagle

Answer 9

Rabbit

Question 10

Name the secondary consumer in this food chain:

Grass-> Rabbit-> Fox-> Eagle

Answer 10

Fox

Question 11

Name the tertiary consumer in this food chain:

Grass-> Rabbit-> Fox-> Eagle

Answer 11

Eagle

Question 12

What do the arrows represent in a food chain?

Answer 12

The transfer of energy

Question 13

What is the name of the grid used in random sampling?

Answer 13

Quadrat

Question 14

Describe a method on how to carry out a random sample.

Answer 14

1) divide area into even sections and number them.
2) using a random number generator select 10 different numbers.
3) place a 1x1m quadrat on the different areas that the number generator selected.
4) count the number of organisms within the quadrat.
5) repeat for all 10 different area numbers.
6) work out the mean number of organisms per quadrat.

Question 15

How would you find the population size in a given area?

Answer 15

1) work out the mean number of organisms per m^2 using random sampling.
2) multiply the mean by the total area.

Question 16

Name the producer in this food chain:

Grass-> Rabbit-> Fox-> Eagle

Answer 16

Grass

Question 17

What are predators?

Answer 17

Consumers that hunt and kill other animals

Question 18

What are prey?

Answer 18

Animals eaten by predators

Question 19

In what tropic level are producers found?

Answer 19

Trophic level 1

Question 20

In what trophic level are herbivores found?

Answer 20

Trophic level 2

Question 21

What percentage of the incident energy from light is transferred for photosynthesis by producers?

Answer 21

About 1%

Question 22

What equation would calculate the efficiency of biomass transfer between trophic levels?

Answer 22

Efficiency=biomass of chosen level/biomass of previous level. x100

Question 23

What is an apex predator?

Answer 23

Carnivore at the top of the food chain that has no predators.

Question 24

Why does not all the biomass get passed up to the next trophic level? Give three reasons.

Answer 24

• Energy lost through movement and respiration.
• Not all ingested material is absorbed into the body, some is lost through faeces.
• Waste products of water and urea are lost through urine.

Question 25

What percentage of biomass from each trophic level is transferred to the level above?

Answer 25

About 10%

Question 26

Label the trophic levels on a pyramid of biomass with 4 levels.

Answer 26

Bottom:
Trophic level 1-producer
Trophic level 2-herbivore-primary consumer
Trophic level 3-carnivore-secondary consumer
Trophic level 4-carnivore-tertiary consumer-apex predictor
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