3.4 Humans And Their Environment

Question 1

What does rapid growth and increased standard of living lead to?

Answer 1

More waste produced

Question 2

What does waste lead to?

Answer 2

Pollution

Question 3

What can be polluted and by what?

Answer 3

Water - with sewage, fertiliser or toxic chemicals
Air - with smoke and gases
Land - with toxic chemicals

Question 4

Which gas pollutes the air and what can it do?

Answer 4

Sulfur dioxide 
Causes acid rain
Kills organisms 
Trees can be damaged if exposed for long periods of time
Change the pH of the soil

Question 5

Which toxic chemicals can pollute the land?

Answer 5

Pesticides and herbicides

Question 6

Why do humans deforest, reducing land for animals and plants?

Answer 6

Building
Farming
Quarrying
Dumping waste

Question 7

What is large scale deforestation in tropical areas used for?

Answer 7

Need for timber

Provides land for agriculture

Question 8

What does deforestation lead to?

Answer 8

Increased release of CO2
Reduced rate at which CO2 is removed by photosynthesis
Reduced biodiversity due to loss of food and habitats

Question 9

What produces methane?

Answer 9

Cattle and rice fields

Question 10

What are peat bogs?

Answer 10

Areas where plants don’t fully decompose upon death

A store of locked up carbon

Question 11

What is peat used in?

Answer 11

Compost in agriculture to improve the nutrient content of soil

Question 12

What happens when peat bogs are destroyed?

Answer 12

They release CO2

Question 13

What should be encouraged?

Answer 13

Using ‘Peat free’ compost

Question 14

How does global warming happen?

Answer 14

The gases CO2 and methane help re-radiate energy back to earth

Question 15

What can global warming cause?

Answer 15

Changes in the earths climate
Rise in sea level
Reduce biodiversity 
Changes in migration patterns of birds
Changes in distribution of species

Question 16

How is CO2 removed?

Answer 16

It can be sequestered in oceans, lakes and ponds

Question 17

How can biofuels be made?

Answer 17

From natural products by fermentation

Question 18

What is the main biogas?

Answer 18

Methane

Question 19

How can methane be produced?

Answer 19

Anaerobic fermentation of plants products or waste material containing carbohydrates

Question 20

Where can the waste used in anaerobic fermentation come from?

Answer 20

Industrial: sugar factories and sewage works

Organic: waste of plants and animal faeces

Question 21

Where is the output of biogas higher?

Answer 21

Warmer countries

Question 22

What are the advantages of biogas?

Answer 22

Useful to recycle waste material 
Fuel is readily available 
Waste is used in fertilisers (called slurry)
Reduces use of fossil fuels
Raw materials are cheap

Question 23

What happens the more stages in a food chain there are?

Answer 23

Less energy and less biomass the organism contains

Question 24

How can efficiency of food production be improved?

Answer 24

Reducing the number of stages in a food chain
Restricting movement
Controlling the temperature of the surroundings
Give the preemptive antibiotics

Question 25

What are happening to fish stocks?

Answer 25

They are declining

Question 26

What rules are fishermen under when fishing?

Answer 26

They can only remove a strict allocation per year

They use certain sized nets to avoid catching smaller young fish

Question 27

What fungus is used to create meat substitutes?

Answer 27

Fusarium

Question 28

Why is Fusarium grown?

Answer 28

To produce Mycoproteins

Question 29

Where is the fungus grown?

Answer 29

On glucose syrup (waste starch) in aerobic conditions and the biomass is harvested and purified

Question 30

How can producing Mycoproteins be produced on a large scale?

Answer 30

In industrial fermenters

Question 31

What do industrial fermenters have?

Answer 31

Air supply
Stirrers or air bubbles
Water cooled jackets
Sensors to monitor pH and temperature