B6.1-2 Flashcards
What is biodiversity?
the variety of living organisims in a habitat
How have humans affected biodiversity (4 Reasons)
- Deforestation
- Agriculture (pesticides, monoculture, fertilisers)
- Pollution (algae growth due to fertilisers, water eutrophication)
- Hunting and Overfishing (loss in numbers/extinction)
What are 5 ways to conserve biodiversity?
- Captive breeding programs (then reintroduce them into the wild)
- Ecotourism — educate public and use money to fund habitats and poacher patrol
- Local Agreements - nature reserves and national parks, restrict human access
- Seed Banks - so you can grow the plants back after extinction
- International Agreements - WWF, etc
Evaluate the advantages and disadvantages of ecotourism
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
Evaluate advantages and disadvantages of captive breeding programs
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
What is eutrophication?
- 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
What is the capture - recapture method of sampling?
- 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
What are 5 capturing methods?
- Pooter - device that if you blow air into and place over animal can capture them and put them into the pooter chamber (small animals)
- 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)
- 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)
- 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)
How can you test for water pollution in a river?
- 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
How can you detect air pollution?
- lichen is very senstive to sulfur dioxide
- you can test by seeing the concentration of lichens from a suspected pollutant
What are 5 threats to food security?
- Developing nations population increases
- Changing diets (e.g quinoa)
- New pests and pathogens
- Conflicts
- Drought/Flooding
How can you sustainably fish?
- fishing quotas to allow pop to recover
- bans on fishing in breeding season + ground
- nets with larger gaps to allow offspring to escape
How are chickens intensively farmed?
- 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
How to maximise crop production?
- maximise photosynthesis
- use hydroponics
What are some negatives of intensive farming?
- Overuse of fertilisers which is not sustainable
- Pesticides and insecticides
What are some solutions to intensive farming?
- Manure/ Animal dung instead of fertilisers
- crop rotation so minerals in soil can regenerate
- biological control instead of pesticides
What is selective breeding?
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
What are some problems with selective breeding?
- Inbreeding is quite common so gene pool is limited
What is genetic engineering?
- a process which involves modifying an organisms genome by introducing a gene from another organism to give a desired characteristic
What are some advantages and disadvantages of GM crops?
- they increase the yield of the crop
- they could make a whole new species/we dont know enough
How do you produce GM insulin: 11 Steps
- You get an insulin producing donor cell
- You remove the DNA from the cell
- You identify the gene for insulin in the DNA
- You cut the gene out with a restriction enzyme
- You remove a plasmid from a bacteria
- You cut open the plasmid with another restriction enzyme
- You put in the insulin gene and a antibiotic resistance gene in the plasmid with a ligase enzyme (now called a recombinant plasmid)
- You put the plasmid back in the bacteria
- You allow the bacteria to reproduce via binary fission
- You put antibiotic on the bacteria and those that survive have had the plasmid successfully
- You extract the insulin once it has been produced and purify it and give it to diabetics
What are some advantages and disadvantages of GM insulin
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
How do you produce a GM plant? 5 Steps
- Pest resistant gene from donor plant cut out using restriction enzyme
- gene is inserted into virus (used as a vector) using ligase enzyme into DNA
- this virus infects the host cell and inserts this gene into the hots DNA
- The transgenic resistant plant grows, which is then clone by scraping some meristem off
- This is then grown into a series of pest resistant plants
