SB9 - Ecosystems and Material cycles

Question 1

What do organisms need to stay alive?

Answer 1

Resources

Question 2

What is an ecosystem?

Answer 2

An area in which all the living organisms and all the non-living physical factors form a stable relationship
–> Needs NO input in order to remain stable

Question 3

Give an example of a large ecosystem:

Answer 3

Rainforest

Question 4

Give an example of a small ecosystem:

Answer 4

Pond

Question 5

What does interdependent mean?

Answer 5

When organisms in an area need each other for resources

E.g. Food & Shelter

Question 6

What is Abiotic factors?

Answer 6

The non-living aspects of an ecosystem

Question 7

Give some examples of Abiotic factors:

Answer 7

• Temperature
• Light intensity
• Moisture
• Pollutants

Question 8

Explain how light intensity affects a community as an abiotic factor

Answer 8

• Light is required for photosynthesis
• Rate of photosynthesis affects the rate at which a plant grows
• Plants can be food sources or shelter for many organisms

Question 9

Explain how Temperature affects a community as an abiotic factor

Answer 9

• Temperature affects the rate of photosynthesis

Question 10

Explain how Moisture levels affects a community as an abiotic factor

Answer 10

• Both plants and animals need water to survive

Question 11

Explain how Soil pH and mineral content affects a community as an abiotic factor

Answer 11

• Soil pH affects the rate of decay
  —> Therefore how fast mineral ions return to soil
  —> Then taken up by other plants
• Different species of plants thrive in different nutrient concentration levels

Question 12

Explain how Wind intensity & direction affects a community as an abiotic factor

Answer 12

• Wind affects the rate of transpiration in plants
• Transpiration affects the temperature of the plant + rate of
  photosynthesis
  —> As it transports water and mineral ions to the leaves

Question 13

Explain how Carbon dioxide levels affects a community as an abiotic factor

Answer 13

• CO2 affects the rate of photosynthesis in plants
• It also affects the distribution of organisms as some thrive in high CO2 environments

Question 14

Explain how Oxygen levels for aquatic animals affects a community as an abiotic factor

Answer 14

• Levels in water vary greatly, unlike oxygen levels in air
• Most fish need a high concentration of oxygen to survive

Question 15

What is Biotic factors?

Answer 15

The living components of an ecosystem

Question 16

Give some examples of Biotic factors:

Answer 16

• Food availability
• Competition
• New pathogens
• New predators and other species

Question 17

Explain how Food availabilitycan affect a community as a biotic factor

Answer 17

More food = organisms can breed more successfully
—> Therefore the population can increase in numbers

Question 18

Explain how New pathogenscan affect a community as a biotic factor

Answer 18

When a new pathogen arises the population has no resistance to it
so they can be wiped out quickly

Question 19

Explain how Compeitioncan affect a community as a biotic factor

Answer 19

If one species is better adapted to the environment than another then it will outcompete it until the numbers of the lesser adapted species are insufficient to breed

Question 20

What is a Community?

Answer 20

All of the populations of different species living together in a habitat

Question 21

Describe the importance of interdependence within a community

Answer 21

Removal or addition of a species to the community can affect the populations of others greatly
–> Changes prey or predator numbers

Question 22

Give some examples on how organisms can be interdependent with each other

Answer 22

• Food
• Shelter
• Reproduction (pollination, seed dispersal)

Question 23

Describe the relationship of biotic and abiotic factors in a stable community

Answer 23

Biotic & Abiotic factors is balanced

Question 24

Describe what the happens in result of a stable community

Answer 24

• The population sizes remain roughly constant
• When they are lost it is very difficult to replace them

Question 25

Give some examples of a **stable community**

Answer 25

* Tropical rainforests * Oak woodlands * Coral reefs

Question 26

What are the *two types* of symbiotic relationships?

Answer 26

* Parasitism * Mutualistic relationships

Question 27

What is a **parasite**?

Answer 27

An organism that lives on (or in a) host organism and takes food from it while it's alive

Question 28

What is **parasitism**?

Answer 28

The interaction between two organisms where only one organism, the parasite, benefits whilst the host does not

Question 29

What is **Mutualism**?

Answer 29

The interaction between two organisms where both benefit as a result of their relationship

Question 30

What can we use to *assess pollution levels*?

Answer 30

Indicator species

Question 31

What is **polluted water** often identified by?

Answer 31

The presence of bloodworms or sludgeworms

Question 32

What are **sludgeworms** also known as?

Answer 32

Sewage worms

Question 33

What is **clean water** often identified by?

Answer 33

The presence of freshwater shrimps and stonefly

Question 34

What is **good air quality** often identified by?

Answer 34

The presence of lichens or blackspot fungus

Question 35

What is **bad air quality** often identified by?

Answer 35

The absence (or little presence) of lichens or blackspot fungus

Question 36

What *pollutant* is present when there is an **absence ( or little presence)** of **lichens or blackspot fungus**

Answer 36

Sulphur dioxide

Question 37

Why is the rose blackspot fungus *more likely* to be found in **less polluted areas**?

Answer 37

As sulphur dioxide protects plants from certain fungi