6.5 Ecosystems

Question 1

What is an ecosystem?

Answer 1

A group of living and non living things that interact with each other.

Question 2

Give 3 components of an ecosystem

Answer 2

Habitat, Population and Community

Question 3

What is the habitat?

Answer 3

The place where the organism lives.

Question 4

What is the population?

Answer 4

All of one species who can breed together and live in the same place.

Question 5

What is the community?

Answer 5

All the populations of different species who live in the same place and interact with each other.

Question 6

What is a species’ niche?

Answer 6

The specific role of each species in an ecosystem

Question 7

What are the two types of factors that affect an ecosystem?

Answer 7

Biotic factors and Abiotic factors

Question 8

Give 3 examples of biotic factors

Answer 8

Producers, Consumers and Decomposers

Question 9

Give 4 examples of abiotic factors

Answer 9

Weather
Temperature
pH
Pollutants

Question 10

Give an example of an abiotic factor that is lethal at both extremes

Answer 10

Temperature

Question 11

Give an example of a abiotic factor that is lethal at one extreme

Answer 11

Pollutants

Question 12

What is the the name given to describe ecosystems constantly changing?

Answer 12

Dynamic

Question 13

What are the three types of changes that affect the population number?

Answer 13

Cyclic
Directional
Erratic

Question 14

Describe cyclical changes

Answer 14

Changes that repeat themselves in rhythm (e.g predator vs prey fluctuations)

Question 15

Describe directional changes

Answer 15

Changes that go in one direction and usually last longe than a life time (e.g erosion)

Question 16

Describe erratic changes

Answer 16

Changes that have no rhythm or direction and are therefore unpredictable (e.g hurricanes)

Question 17

What is lost at each trophic level?

Answer 17

Biomass

Question 18

What is used to calculate the biomass or an organism?

Answer 18

An organism’s dry mass

Question 19

What is used to calculate biomass transfer?

Answer 19

Ecological Efficiency

Biomass transferred to higher trophic level / biomass at lower trophic level

Question 20

What can be used to represent biomass transfer?

Answer 20

A pyramid of biomass

Question 21

What is gross primary productivity?

Answer 21

The rate at which plants convert light energy into chemical energy by photosynthesis

Question 22

What is secondary productivity?

Answer 22

The rate at which consumers produce biomass

Question 23

What limits both primary and secondary productivity?

Answer 23

Respiration

Question 24

What are saprotrophs?

Answer 24

Bacteria and fungi that decompose dead organisms by secreting digestive enzymes onto the dead matter and absorbing the material.

Question 25

How is nitrogen gas obtained by plants

Answer 25

Nitrogen fixing

Question 26

Describe nitrogen fixing?

Answer 26

A nitrogen is unreactive, it has to be fixed by nitrogen fixing bacteria in soil or roots to form nitrogen or ammonium ions. It can also happen through the haber process or lightening striking.

Question 27

What is ammonification?

Answer 27

When chemoautotrophic bacteria (such as nitrosomonas) oxidises ammonia to form nitrates

Question 28

What is nitrification?

Answer 28

When chemoautotrophic bacteria (such as nitrobacters) oxidise nitrites to form nitrates

Question 29

How are nitrates used by plants?

Answer 29

To produce amino acids and nucleotide bases

Question 30

What is denitrification?

Answer 30

When nitrates are converted back into nitrogen gas by bacterias