B16/17/18 Ecology

Question 1

Biodiversity definition

Answer 1

Biodiversity is the variety of all the different species of organisms on Earth, or with an ecosystem.

Question 2

What does the future of the human species rely on in terms of biodiversity?

Answer 2

The future of the human species on Earth relies on us maintaining a good level of biodiversity. Many human activities are reducing biodiversity.

Onky recently, measures have been taken to prevent this reduction.

Question 3

Why has the global population increased so much recently?

Answer 3

The population has risen due to lots of medical advances keeping people alive more.

Question 4

What are the consequences of this population explosion?

Answer 4

• Pollution (water and air)
• Global warming, the Greenhouse effect and climate change
• Peat bog destruction
• Food security

Question 5

Why do people need land?

Answer 5

• Housing, retail, roads, industry
• Farming
• Quarrying
• Waste disposal

Question 6

What happens when people use land?

Answer 6

• Habitats are destroyed
• Earth’s resources are drained
• There is a huge amount of waste for disposal
• Many pollutants
• Biodiversity decreases

Question 7

What happens when we make more things?

Answer 7

We produce more waste, including waste chemicals.

Question 8

What does pollution affect?

Answer 8

It affects water, land and air which kills plants and animals, reducing biodiversity.

Question 9

How does pollution affect water?

Answer 9

Sewage and toxic chemicals from industry can pollute the water which affects the plants and animals who rely on them for survival.

Question 10

How does pollution affect land use?

Answer 10

We use toxic chemicals for farming. We also bury nuclear waste underground, and we dump a lot of household waste in landfill sites.

Question 11

How does pollution affect the air?

Answer 11

Smoke and acidic gases reduced into the atmosphere can pollute the air.

Question 12

What are the consequences of global warming?

Answer 12

1. Higher temperatures cause seawater to expand and ice to melt, causing the sea level to rise. It will lead to flooding, resulting in the loss of habitats.
2. The distribution of many wild animal and plant species may change as temperatures increase. Some species may become more widely distributed and other species may become less widely distributed
3. There could be changes in migration patterns.
4. Biodiversity could be reduced if some species are unable to survive a change in the climate.

Question 13

3 What does a food chain always start woth?

Answer 13

All food chains start with PRODUCER which make molecules like glucose.

Question 14

3 What are food webs?

Answer 14

These are constructed from lots of food chains in a habitat.

Question 15

3 What is biomass?

Answer 15

The dry mass of an organism

Question 16

3 What happens to the biomass of a product after a particular step in the food chain?

Answer 16

The total biomass at a particular step in a food chain is always less han the total biomass at the step before it.

Question 17

3 What is the percentage of biomass being transfered from one trophic level to another?

Answer 17

10% is used to build new biomass

Question 18

3. Why is there only 10% biomass transfered to the next trophic level? Name at least 3

Answer 18

Losses of biomass are due to:

• Not all of the ingested material is absorbed
• Some is egested as faeces
• Some is excreted as carbon dioxide and water (during respiration) and water and urea in urine
• Some is used in metabolic processes and is lots as thermal energy

Question 19

3 How do simple food chains work?

Answer 19

Producers are eaten by primary consumers, which are eaten by secondary consumers and then tertiary consumers.

Question 20

What are predators

Answer 20

Consumers that kill and eat other animals

Question 21

What are prey?

Answer 21

Those that are eaten are prey

Question 22

What happens when there is plenty of food?

Answer 22

Prey animals grow in numbers

Question 23

What happens when prey numbers go up?

Answer 23

More food for predators

Question 24

What happens when there is more food for predators?

Answer 24

Population increases for predators

Question 25

What happens if there is more food for predators?

Answer 25

More prey gets eaten so snumbers of prey go down

Question 26

What happens when there is fewer prey?

Answer 26

Less food for predators so predator population starts to decrease

Question 27

What happens when there are less predators

Answer 27

Prey animals can grown in numbers

Question 28

4 Why is material in the living world recycled?

Answer 28

It is used to provide building blocks for future organisms

Question 29

4 What are decomposers?

Answer 29

Decomposers are a group of miccroorganisms that include bacteria and fungi.

Question 30

4. What do decomposers do?

Answer 30

They break down waste and dead animals and plants to return/recycle the organic matter needed for building blocks.

Question 31

4 Steps of water cycle

Answer 31

1. Condensation - As moist air rises it cools, water vapour condenses back into liquid water droplets producing clouds 2. Precipitation - As water droplets in clouds get heavier they fall as rain, snow or hail. 3. Evaporation - The Sun heats the Earth's surface and water is turned from liquid into water vapour forming warm moist air. 4. Transpiration and Respiration - Loss of water vapour from plants and animals directly to the atmosphere

Question 32

4 Word equation for combustion

Answer 32

Fuel + Oxygen ---> Carbon Dioxide + Water

Question 33

All the steps of the Carbon Cycle

Answer 33

1. CO2 is removed from the atmosphere by green plants and algae during photosynthesis. 2. When the plants and algae respire, some carbon is returned to the atmosphere as CO2 3. The plant and algae are eaten by animals so some carbon becomes part of the fats and proteins in their bodies. 4. When the animals respire, some carbon is returned to the atmosphere CO2 5. Miccorganisms feed on the plants, algae and animals when they die so these organisms respire, CO2 is returnee to the atmosphere 6. Animals also produce waste that is broken down by detritus feeders and microorganisms 7. The combustion of wood and fossil fuels also releases CO2 back into the atmosphere 8. So the carbon is constantly being cyclee - from the air, through food chains and eventually taken back into the air.