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Question 1

What is an ecosystem?

Answer 1

The interaction of a community with abiotic parts of the environment

Question 2

How do abiotic factors affect communities?

Answer 2

1. Light intensity —
   —> increases rate of photosynthesis
   —> plants can be food sources for other organisms
2. Temperature —
   —> increases rate of photosynthesis
3. Water levels —
   —> plants and animals need water to survive

Question 3

How do biotic factors affect communities?

Answer 3

1. Competition —
   —> if some species are better adapted to the environment, they will outcompete others
2. Predation —
   —> some species will eat others

Question 4

Why is interdependence important?

Answer 4

Organisms will depend on other organisms for vital services

Question 5

When would you put Quadrats randomly?

Answer 5

When estimating population size

Question 6

When would you put Quadrats in regular intervals?

Answer 6

When measuring changes in distribution and abundance of organisms

Question 7

What is parasitism?

Answer 7

When one organism feeds off a host and causes harm to it
—> only one organism benefits

Question 8

Why is not all energy transferred to the next trophic level?

Answer 8

1. Not all biomass can be eaten
2. Glucose is used in respiration, which releases energy
3. Urea is a waste substance which is released in urine

Question 9

What are some positive human interactions with ecosystems?

Answer 9

1. Maintaining rainforests
   —> habitats are preserved
2. Reducing water pollution
   —> saves plants/animals in water

Question 10

What is the process of eutrophication?

Answer 10

1. Fertiliser is added
2. Heavy rain washes fertiliser off
3. Nitrates and phosphates dissolve in soil water
4. They are washed into the stream
5. Plants and algae grow rapidly in the water
6. They block sunlight so plants in water die and stop releasing oxygen
7. Bacteria use oxygen in water to break down dead materials
8. Oxygen concentration decreases
9. Aquatic animals die due to lack of oxygen