B18: Biodiveristy

Question 1

biodiversity?

Answer 1

variety of different species of organsims on earth/within an ecosystem

Question 2

how does biodiversity ensure stability of ecosystems?

Answer 2

reduces dependency on other organsims for shelter and food

Question 3

how are human activities reducing biodiversity?

Answer 3

population growth means :
- more land used for houses, factroies etc
- more waste
- pollution of water -> more sewage/toxic chemicals pollute water

Question 4

sources of water pollution?

Answer 4

toxic chemicals/pesticides- run off into water sources - lead to death/failure to breed
untreated sewage - sewage is good food for bacteria, so will increase and deplete oxygen levels in water as respire aerobically –> EUTROPHICATION /death of animals
fertilisers - increases algae/water plants so water plants at bottom die bc lack of sunlight

Question 5

sources of land pollution?

Answer 5

toxic chemcials
discarded rubbish - toxic chemicals from rubbish/landfill can go into soil

Question 6

sources of air pollution?

Answer 6

sulfur dioxide/nitrogen oxides - acid rain can damage leaves, flowers
- can make rivers too acidic -> death of aqautic animals

Question 7

how do humans reduce amount of land available?

Answer 7

building, quarrying, farming, dumping waste

Question 8

what are peat bogs?

Answer 8

bogs are areas of land that are waterlogged /acidic
- plants that die dont fully decay due to lack of oxygen
- the partly decomposed plant matter accumilates over time to form peat

Question 9

why are peat bogs destroyed /impact?

Answer 9

• to be used for farming
• peat can be used for fuel
• produce compost to increase food production

IMPACT : CO2 released when peat is burned as fuel

Question 10

why is deforestation happening in tropical areas?

Answer 10

• provide land for farming cattle/rice fields
• grow crops for biofuels

Question 11

consequence of deforestation?

Answer 11

extinction/loss of biodiversity
soil erosion - tree roots stabalise soil
- without trees , minerals are unused so washed away into rivers/lakes by rain (leaching)

flooding - topsoil will be loose/unstable so washes away –> increases flooding
CO2

Question 12

consequences of global warming?

Answer 12

Melting ice caps
Rising sea levels
increasing temps –> flooding, drought
increased migration of species
extinction –> decrease biodiversity

Question 13

positive human interactions with ecosystems?

Answer 13

• maintaining rainforests
• reducing water pollution
• preserving areas of scientific interest
• replanting hedgrows/woodlands

Question 14

negative interactions with ecosystems?

Answer 14

• production of greenhouse gases
• so2 from factories –> acid rain
• chemical from agriculture
• clearing land to build on

Question 15

how to reduce our negative impact on ecosystems?

Answer 15

1. breeding programs - stop endangered species from extinction
2. protect rare habitats - stop extinction of animals in that area/ may have to be regenerated
3. reintroduction of hedgrows/field margins around land where only 1 type of crop is grown - maintains biodiveristy (provide habitats/ field lines allow wild flwoers/grasses to grow)
4. reduce deforestation/CO2 emissions- slows down global warming
5. recycling - reduces land taken up by landfill

Question 16

trophic levels ?

Answer 16

level 1 : PRODUCERS - photsynthetic organisms (plants and alage)
level 2 : PRIMARY CONSUMERS - herbivores
level 3 : SECONDARY CONSUMERS - predators
level 4: TERTIARY CONSUMERS - predators
level 5 : QUATENARY- APEX predators

Question 17

how do decomposers break down organic matter?

Answer 17

secrete enzymes
- break food into small soluble food molecules
- these molecules then absorbed by decomposers

Question 18

what is biomass pyramid ?

Answer 18

shows relative biomass at each trophic level

Question 19

why is the biomass less as u go up pyramid?

Answer 19

not all food consumed is converted to biomass
- some biomass lost in respiration/ urine

Question 20

how is bomass transfered?

Answer 20

Primary consumers eat producers , they break down biomass of producer and use the chemical energy to increase/sustain own biomass
- this repeats at every trophic level

Question 21

efficiency of biomass transfer equn?

Answer 21

Biomass transferred to next level/biomass available in previous level x 100

Question 22

factors effecting food security?

Answer 22

INCREASED BIRTH RATE
CHANGING DIETS
NEW PEST/PATHOGENS - destroy crops
CLIMATE CHANGE - affect food production
CONFLICTS

Question 23

how can efficency of food production be increased ?

Answer 23

aim to increase the amount of energy converted into biomasss by restricting energy transfer from animals to environment by:
1. limiting movement - kept in cages
2. controlling temps of surrounding - livestock kept at optimum temp so use less energy regulating body temp
3. fed high protein food to increase growth

Question 24

ethical objections to intensive farming methods?

Answer 24

• disease can spread easily
• unethical to make animals live in unnatural/uncomfortabe conditions

Question 25

advanatges and disadvatages to modern farming techniques?

Answer 25

AD: livestock given **antibiotics** with food - growing one type of crop increases **yield/profit** - using fertilisers increase **plant growth** --> increase food yield DIS : unethical to keep animals **confined** - giving livestock antibiotics may cause **antibiotic resistance** - growing 1 type of crop **decrease biodiviersity** - fertilsers can cause eutrophication

Question 26

how to maintain fish stocks at a level where breeding continues?

Answer 26

**sustainable fisheries** - fisheries where overall population size doesnt decrease - bc no fish caught doesn't exceed no. fish born **controlling net size** - allow unwanted species to escape in larger net gaps - juvenile fish can escape so can reach breeding age/produce offspring before caught **fish quotas** - limit no./size of fish species that can caught in an area

Question 27

how can Fusarium produce mycoprotein?

Answer 27

fungus is grown in aerobic conditions/provided with glucose syrup as food source - fungus grows and multiplies in fermenter - fungus is then hervested/purified to produce mycoprotein -> protein suitable for vegs

Question 28

how is biotechnology used to provide sufficient food fro increasing population?

Answer 28

**Mycoprotein** - protein rich products good for vegetarians **GM crops** - modified to be resistant to pests/weather --> incresing yield - modifying them to increase nutritional value

Question 29

Required Practical : decay

Answer 29

Place 20cm cubes of fresh milk in 3 beakers - decide 3 temps you’ll investigate and write in each beaker Use universal indicator to determine pH of each beaker - cover each beaker in cling film/ put in water bath to get them to same temp - universal indicator again for each of the beakers after 24,48,62 hrs