B8 - Humans and the Environment

Question 1

the main pollutant that causes acid rain is

Answer 1

D - sulfur dioxide

Question 2

describe how pH affects the variety of organisms in the lake

Answer 2

• as pH decreases so does number of species

- all organisms in lake are found at 6.0

Question 3

explain the problems associated with an increase in nitrates and phosphates levels in a lake

Answer 3

• eutrophication
• causes algal bloom
• • plants at bottom of the lake cannot get light to photosynthesise
• they die :(
• micro-organism break them down and respire moving oxygen from water
• reduction in biodiversity

Question 4

clean water. — indicator species

polluted water — indication species

Answer 4

clean water - freshwater shrimp

polluted water - bloodworm

Question 5

explain how the use of pesticides may benefit maize production

Answer 5

• reduces number of pests

- reduces damage to crop and increases yield

Question 6

maize plants can be used in production of biofuel

discuss advantages and disadvantages of the use of biofuel

Answer 6

ADV:

• removes carbon when growing
• less use of fossil fuels
• renewable / sustainable

DIS:

• reduced food production
• takes up land
• reduces biodiversity

Question 7

what is the name of process one

Answer 7

C - photosynthesis

Question 8

describe the numbered processes that return carbon dioxide back into the atmosphere

Answer 8

• respiration in animals (arrow 2)
• respiration in plants (arrow 5)
• decomposition by microorganism (arrow 3)

Question 9

human population is increasing

explain how this could change the concentration of co2 in the atmosphere

Answer 9

• increase in carbon levels

- due to increase in burning of fossil fuels

Question 10

name an indicator species used to monitor air quality

Answer 10

• lichen

Question 11

explain affects of eutrophication that may lead to death of aquatic animals

Answer 11

• increased algae bloom
• blocks sunlight from plants growing at bottom of lake
• stops photosynthesis
• plants die and decomposes break them down
• which uses oxygen for respiration

Question 12

explain which location in stream is most polluted

Answer 12

C because least amount of greasy water shrimp is found there

Question 13

location a had other organisms present

these are likely to be

Answer 13

D - stonefly

Question 14

some nitrate fertilisers leaked into the stream and causes

Answer 14

C - eutrophication

Question 15

describe what will happen to the organisms in the stream when nitrates leak from the factory

Answer 15

• algae rapidly grow
• block light from photosynthesising plants
• plants on stream bed die
• decomposes use up oxygen to break down dead plants
• other organisms die die to lack of oxygen

Question 16

state the impact of this energy loss on length of food chain

Answer 16

• it limits the length of the food chain

Question 17

calculate percentage of organisms in stream A that are clean water indications

Answer 17

70%

Question 18

use results to explain which stream is more polluted

Answer 18

• stream b is more polluted than stream a because stream A contains stonefly larvae which are indicators of clear water