B6.1-2

Question 1

What is biodiversity?

Answer 1

the variety of living organisims in a habitat

Question 2

How have humans affected biodiversity (4 Reasons)

Answer 2

• Deforestation
• Agriculture (pesticides, monoculture, fertilisers)
• Pollution (algae growth due to fertilisers, water eutrophication)
• Hunting and Overfishing (loss in numbers/extinction)

Question 3

What are 5 ways to conserve biodiversity?

Answer 3

1. Captive breeding programs (then reintroduce them into the wild)
2. Ecotourism — educate public and use money to fund habitats and poacher patrol
3. Local Agreements - nature reserves and national parks, restrict human access
4. Seed Banks - so you can grow the plants back after extinction
5. International Agreements - WWF, etc

Question 4

Evaluate the advantages and disadvantages of ecotourism

Answer 4

Advantages:
- money generated can be used to fund conservation efforts for the habitat
- poacher patrols can be funded
Disadvantages:
- by drawing more people to the place, there will probably be more trampling than before
- pollution from cars and human infrastructure for tourists

Question 5

Evaluate advantages and disadvantages of captive breeding programs

Answer 5

Advantages:
- they can stabilise populations of near extinct species
- they can reintroduced to the wild, increasing biodiversity
Disadvantages:
- they do not know how to hunt/ are not integrated with the wild
- there is difficulty finding suitable reintroduction sites

Question 6

What is eutrophication?

Answer 6

• fertilisers from the soil used too much
• the rain causes it to run off into a nearby pond/lake
• algae uses these fertilisers and grows rapidly
• this blocks the lake from oxygen and photosynthesis that the organisms in the lake need

Question 7

What is the capture - recapture method of sampling?

Answer 7

• the animals in a certain sample area are trapped
• you count them and mark them
• come back after a suitable period of time to the same area
• trap the animals
• count them and see how many are marked
• use this formula to find population size

Pop Size = Count1 x Count2 / No. in 2nd count that were tagged

Question 8

What are 5 capturing methods?

Answer 8

1. Pooter - device that if you blow air into and place over animal can capture them and put them into the pooter chamber (small animals)
2. Pitfall Trap - (pits dug in place, with canopy overhead to stop flooding, organisms fall in but cannot climb out so they can be identified and releases)
3. Sweep Net - larger handheld nets that can be swept across trees leaves to capture invertebrates in the tree (must be done systematically, e.g 10 second sweep at 2 metre height)
4. Kick Sampling - (scientist stands in stream and uses feet to gently agitate stream bed while having a net downstream, and those organisms that are disturbed are captured for id)

Question 9

How can you test for water pollution in a river?

Answer 9

• you can test the type of organisms up and downstream of the suspected pollutant
• e.g stone nymphs need clean oxygenated water, but a sludgeworm does not

Question 10

How can you detect air pollution?

Answer 10

• lichen is very senstive to sulfur dioxide
• you can test by seeing the concentration of lichens from a suspected pollutant

Question 11

What are 5 threats to food security?

Answer 11

1. Developing nations population increases
2. Changing diets (e.g quinoa)
3. New pests and pathogens
4. Conflicts
5. Drought/Flooding

Question 12

How can you sustainably fish?

Answer 12

• fishing quotas to allow pop to recover
• bans on fishing in breeding season + ground
• nets with larger gaps to allow offspring to escape

Question 13

How are chickens intensively farmed?

Answer 13

• they’re movement is restricted so biomass is optimised
• they have antibiotics mixed in with their feed to stop illness
• theyre kept in warm enclosures

Question 14

How to maximise crop production?

Answer 14

• maximise photosynthesis
• use hydroponics

Question 15

What are some negatives of intensive farming?

Answer 15

1. Overuse of fertilisers which is not sustainable
2. Pesticides and insecticides

Question 16

What are some solutions to intensive farming?

Answer 16

1. Manure/ Animal dung instead of fertilisers
2. crop rotation so minerals in soil can regenerate
3. biological control instead of pesticides

Question 17

What is selective breeding?

Answer 17

This is where humans artificially select the animals or plants they want to breed together so that the genes for a desired characteristic can remain in the population

Question 18

What are some problems with selective breeding?

Answer 18

• Inbreeding is quite common so gene pool is limited

Question 19

What is genetic engineering?

Answer 19

• a process which involves modifying an organisms genome by introducing a gene from another organism to give a desired characteristic

Question 20

What are some advantages and disadvantages of GM crops?

Answer 20

• they increase the yield of the crop
• they could make a whole new species/we dont know enough

Question 21

How do you produce GM insulin: 11 Steps

Answer 21

1. You get an insulin producing donor cell
2. You remove the DNA from the cell
3. You identify the gene for insulin in the DNA
4. You cut the gene out with a restriction enzyme
5. You remove a plasmid from a bacteria
6. You cut open the plasmid with another restriction enzyme
7. You put in the insulin gene and a antibiotic resistance gene in the plasmid with a ligase enzyme (now called a recombinant plasmid)
8. You put the plasmid back in the bacteria
9. You allow the bacteria to reproduce via binary fission
10. You put antibiotic on the bacteria and those that survive have had the plasmid successfully
11. You extract the insulin once it has been produced and purify it and give it to diabetics

Question 22

What are some advantages and disadvantages of GM insulin

Answer 22

A:
- supply the growing demand of insulin
- less side effects as before pigs insulin was used, people disagreed with it
D:
- Only works if bacteria can produce the human insulin

Question 23

How do you produce a GM plant? 5 Steps

Answer 23

1. Pest resistant gene from donor plant cut out using restriction enzyme
2. gene is inserted into virus (used as a vector) using ligase enzyme into DNA
3. this virus infects the host cell and inserts this gene into the hots DNA
4. The transgenic resistant plant grows, which is then clone by scraping some meristem off
5. This is then grown into a series of pest resistant plants