B2f

Question 1

What does an expose to more UV rays do to the ocean?

Answer 1

• an increase in UV rays might kill plankton in the sea
• this could have a massive effect on the sea ecosystem because plankton are on the bottom of the food chain
• scientist predict fish levels will drop.

Question 2

What are indicator species?

Answer 2

• species can be used to show pollution in areas

- some species can only survive in unpolluted conditions

Question 3

What indicator species show low pollution?

Answer 3

• lichens are used to monitor air quality (they’re damaged by pollution). The cleaner the air, the greater diversity of lichens that survive
• mayfly larvae are used to monitor air quality (they can’t survive in polluted water). The cleaner the water, the more mayfly larvae survive

Question 4

What indicator species show high pollution?

Answer 4

• water lice, rat-tailed maggots and sludgeworms all indicate polluted water.
• rat-tailed maggot and sludgeworms indicate a very high level of pollution

Question 5

How can pollution levels be measured with indicator species?

Answer 5

• a survey to see if a species is present or absent from the area. It is a quick way to tell if the area is polluted or not, but not how polluted
• count the number of times an indicator species occurs in an area will give you a numerical value, letting measurements from different areas to be compared so you can see how polluted an area is

Question 6

What are the advantages and disadvantages of indicator species?

Answer 6

• measuring pollution directly
• sensitive instruments measure the concentration of chemical pollutants in samples of air and water
• satellite data can also be used to indicate pollutant levels, e.g. satellites show where the ozone layer is thin or absent

Question 7

What are the disadvantages and advantages of measuring pollution with instruments?

Answer 7

• advantage: living methods are quick, cheap and easy way of saying whether an area is polluted or not. No expensive equipment or highly trained workers needed
• disadvantages: factors other than pollution can influence the survival of indicator species so living methods aren’t always reliable

Question 8

How can pollution levels be measured with machinery?

Answer 8

-advantages: directly measuring the pollutants give reliable, numerical data that’s easy to compare between different sites
,the exact pollutant is detected
-disadvantages: non-living methods require more expensive equipment and trained workers than methods that use indicator species