Humans and their environment

Question 0

What happens if waste is not properly handled?

Answer 0

more pollution will be caused

Question 1

Why is increasingly more waste being produced?

Answer 1

Rapid growth in human population and an increase in the standard of living

Question 2

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

Answer 2

building, quarrying, farming and dumping waste

Question 3

What may human’s waste pollute?

Answer 3

water with sewage, fertiliser or toxic chemicals.

Air with smoke and gases e.g auld ur dioxide which contributes to acid rain

land with toxic chemicals e.g pesticides and herbicides which may then be washed into waterways

Question 4

Why is there large scale deforestation in tropical areas?

Answer 4

due to need for timber to provide land for agriculture

Question 5

What impacts has deforestation had?

Answer 5

increased release of CO2 into atmosphere via burning of the wood and activities of microorganism

reduced rate at which CO2 is removed from the atmosphere (photosynthesis)
and stops trees ‘locking up’ CO2

reduced biodiversity due to loss of food and habitats

Question 6

Why has deforestation occurred?

Answer 6

Allow crops to be grown to produce ethanol-based biofuels

allow increase in cattle and rice fields to provide food. However methane is produced by these organisms

Question 7

What happens when peat bogs are destroyed?

Answer 7

CO2 released into atmosphere because peat used as compost which microorganisms decay

Question 8

What is an environmentally friendly alternative to peat bogs?

Answer 8

Peat free composts

Question 9

What gas levels are increasing in the atmosphere and what are they contributing to?

Answer 9

Increased levels of CO2 and methane contribute to global warming

Question 10

What happens if the earths atmosphere increases by only a few degrees Celsius?

Answer 10

climate change
rise in sea level
reduction of biodiversity 
changes in migration patterns of animals e.g birds
changes in distribution of species

Question 11

How is CO2 related to oceans, lakes and ponds and why is this important?

Answer 11

CO2 sequestered in oceans, lakes and ponds. Important in removing CO2 from atmosphere

Question 12

What is a biofuel?

Answer 12

fuel produced from biological material which is renewable and sustainable

Question 13

Name the process by which ethanol based fuels are produced

Answer 13

fermentation

Question 14

Describe the process of producing ethanol-based biolfuels

Answer 14

Glucose produced from maize starch by the action of carbohydrase

Glucose and sugar cane juices then fermented by anaerobically respiring yeast

Produced ethanol which is extracted via distillation and used as fuel in motor vehicles

Question 15

What can ethanol be described as and why?

Answer 15

Carbon neutral as only the CO2 used for photosynthesis by the crops is released into the atmosphere when ethanol is burned

Question 16

What is biogas?

Answer 16

mainly methane

Question 17

How is biogas produced?

Answer 17

anaerobic fermentation by bacteria

Question 18

Describe the process of producing biogas

Answer 18

Plants and waste material containing carbohydrates (e.g cattle dung), broken down by biogas generators

Question 19

What do generators provide?

Answer 19

ideal conditions for bacteria to reproduce and ferment carbohydrates

Question 20

What to generators produce in tho process?

Answer 20

slurry which can be used as fertiliser

Question 21

what can biogas be used for?

Answer 21

cooking, heating or refrigeration

Question 22

What do large scale generators use?

Answer 22

waste from sugar factories or sugar works

Question 23

Where can small scale generators be used?

Answer 23

at home or on a farm

Question 24

How is temperature maintained in biogas generators?

Answer 24

using insulating jackets or being buried underground for insulation

Question 25

What uses oxygen free conditions?

Answer 25

biogas generators

Question 26

What happens at each stage of the food chain?

Answer 26

less material and less energy contained in the biomass of the organisms so less stages=more efficient

Question 27

How can meat be produced more efficiently?

Answer 27

Preventing animal from moving so that no energy wasted on movement

keeping animal warm so no energy lost on maintaining body temp

Question 28

What is happening to fish stocks?

Answer 28

declining

Question 29

How are fish stocks maintained?

Answer 29

Fishing quotas - fishermen can only remove a strict allocation per year

Nets with big holes - avoid catching small and young fish which can reproduce

Question 30

How is mycoprotein produced?

Answer 30

using fusarium (fungus) which is grown aerobically on cheap sugar syrup made from waste starch

mycoprotein then harvested

Question 31

What do industrial fermenters have?

Answer 31

air supply providing oxygen for respiration

stirrer or gas bubbles used to keep microorganisms spread out and to provide even temp

water-cooked jacket around outside as respiring microorganisms release energy which heats up contents

sensors to monitor pH and temp