Humans and their environment

Question 1

Why has there been an increase in waste from human activity?

Answer 1

A rapidly growing human population with an increasing standard of living.

Question 2

What will happen if waste isn’t handled properly?

Answer 2

More pollution will be caused.

Question 3

Waste may pollute water how?

Answer 3

With sewage, fertiliser or toxic chemicals.

Question 4

Waste may pollute air how?

Answer 4

With smoke and gases, such as sulphur dioxide which contributes towards acid rain.

Question 5

Waste may pollute the land how?

Answer 5

With toxic chemicals such as pesticides and herbicides, which may be washed into waterways.

Question 6

How do humans reduce the amount of land for other animals and plants?

Answer 6

By building, quarrying, farming and dumping waste.

Question 7

Large scale deforestation for timber and land for agriculture in tropical areas has had what effects?

Answer 7

Increased the amount of carbon dioxide released into the atmosphere by the burning of the wood and by the activity of microorganisms.
Reduced the rate at which carbon dioxide is removed from the atmosphere and ‘locked up’ in wood for many years.

Question 8

Deforestation leads to a what in biodiversity?

Answer 8

Decrease.

Question 9

Why has deforestation occurred?

Answer 9

For crops to be grown from which biofuels, based on ethanol, can be produced.
Increase in space for cattle or rice to grow due to increase in food demands.

Question 10

Disadvantage of deforestation for cattle grazing:

Answer 10

Cattle produce huge amounts of methane which has led to an increase in methane levels in the atmosphere. Methane is a greenhouse gas.

Question 11

Destruction of peat bogs and other areas of peat leads to what?

Answer 11

An increase of carbon dioxide in the atmosphere.

Question 12

Instead of using peat people and governments are turning to what as a sustainable source of soil nutrients?

Answer 12

‘Peat-free’ composts.

Question 13

Increasing levels of methane and carbon dioxide in the atmosphere cause what?

Answer 13

Global warming.

Question 14

An increase in the world’s temperature by a few degrees Celsius can lead to:

Answer 14

Big changes in the Earth's climate.
Sea level rise.
Reduction in biodiversity.
Changes in migration patterns.
Changes in distributions of species.

Question 15

Carbon dioxide can be sequestered where?

Answer 15

In oceans, lakes and ponds. It is an important factor in removing carbon dioxide from the atmosphere.

Question 16

Biofuels are generally made from what?

Answer 16

They are made from natural products of fermentation.

Question 17

How can biogas be made?

Answer 17

Biogas, mainly methane, can be produced by anaerobic respiration of plant products or waste containing carbohydrates.

Question 18

At each stage of a food chain the amount of energy and biomass…

Answer 18

…decrease.

Question 19

Energy efficiency in food chains can be improved how?

Answer 19

By reducing the number of stages in the food chain.

By restricting energy loss in animals by restricting movement and heat loss to surroundings.

Question 20

Fish stocks are…

Answer 20

…declining.

Question 21

What must be done with fish stocks to ensure some species don’t become extinct in certain areas?

Answer 21

The must be maintained at a level where breeding takes place.

Question 22

How can fish stocks be managed/protected?

Answer 22

Regulating net sizes and introducing fishing quotas.

Question 23

The fungus Fusarium can be used to do what?

Answer 23

For producing mycoprotein, an important protein substitute for vegetarians.

Question 24

Fusarium is grown in what conditions?

Answer 24

It is grown on a glucose syrup in aerobic conditions. The biomass is then harvested and purified.