biodiversity

Question 1

what is biodiversity?

Answer 1

• the variety of living organisms living in an area

Question 2

what are the three types of biodiversity?

Answer 2

• species, genetic, habitat

Question 3

define species BD

Answer 3

• the number of different species and individuals within each species in a community

Question 4

define genetic BD

Answer 4

the variety of genes amongst all the individuals in a population of one species

Question 5

define habitat BD

Answer 5

the range of different habitats

Question 6

what is species diveristy broken down into?

Answer 6

• richness and evenness

Question 7

how can genetic diversity be measured?

Answer 7

• polymorphism.
• number of polymorphic gene loci/total number of loci.
• most genes are monomorphic

Question 8

How can sampling be made representative?

Answer 8

• large sample
• random
• calculate mean and statistical test

Question 9

What is on method of random sampling?

Answer 9

• two tape measures at right angles to create a grid
• random number generator to generate two numbers which serve as coordinates on the grid

Question 10

What are the three non-random sampling techniques?

Answer 10

• opportunistic. unlikely to result in accurate data. biased as only samples organisms which are conveniently available.
• stratified. some populations or habitats can be separated into groups to sample from (strata). E.g a pond: surface, shallow, deep. Take random samples within each strata
• systematic. belt transect. Change in distribution. Set intervals.

Question 11

two types of qudrat?

Answer 11

• point quadrat: pin pushed through. Whatever species touch it are recorded. Horizontal bar with hoes along it.
• frame quadrat: a square frame of a known size.

Question 12

Uses of quadrats (3)

Answer 12

• density: count individuals present.
• frequency: Count how many squares out of the 100 have the species in.
• % cover: estimate the percentage of the entire quadrat covered with the species that is being investigated. Quick, but subjective and therefore lower accuracy. Can be improved by standardisation of how % is estimated.

Question 13

What factors affect biodiversity?

Answer 13

• human population increase; more land required for building. Deforestation.
• agriculture; clearing land results in habitat destruction and chemical pesticides or fertilisers may be added. Monocultures.
• climate change; melting polar ice caps result in flooding. Less rain and higher temps mean some species can’t survive. Xerophyte dominance

Question 14

reasons to maintain biodiversity?

Answer 14

• ecological: all organisms interdependent on each other, incl. humans. Knock on effect on our food security.
• Economic: soil erosion and monocultures deplete soil of mineral content, worsening an area’s crop production. Tourism to natural beauty. Medicines.
• Aesthetic: enriches people lives. Creative inspiration, mental health

Question 15

methods of maintaining BD (conservation)?

Answer 15

• in situ and ex situ

Question 16

in situ conservation?

Answer 16

• happens within the habitat.
• genetic diversity is maintained as individuals are not bred captively.
• Interdependence of organisms; preventing extinction of one species will support many others.
• wildlife reserves and marine conservation zones. Designated areas for wildlife to recover and repopulate. Limited fishing and tourism

Question 17

ex situ conservation?

Answer 17

• removing organisms from their natural habitat to try and protect them; usually in addition to in situ measures.
• botanical gardens can provide the optimal conditions for a huge
• captive breeding: programmes to reproduce animals in zoos and aquariums. Increase number of endangered species which may be reintroduced.
• seed banks are stores of genetic material. Seeds of a variety of plant species are stored in water and temp controlled environments to keep them viable for longer. Stored as a backup for potential plant species that may go extinct.

Question 18

What is CITES?

Answer 18

• Convention on International Trade in Endangered Species
• 145 countries signed in 1973.
• cooperation and agreement between countries
• Drives up price of illegal substances like ivory.

Question 19

What is the Rio Convention on Biological Diversity?

Answer 19

• Began in 1992, 172 nations signed.
• sustainable development, reduced greenhouse emissions, prevent desertification and drought.
• Share access to scientific knowledge and technology.

Question 20

What is the CSS?

Answer 20

• countryside stewardship scheme
• Protect and enhance the natural environment

Question 21

how can large moving populations be estimated?

Answer 21

capture-recapture

Question 22

examples of abiotic factors?

Answer 22

• wind speed
• temperature
• soil pH
• light intensity
• humidity
• oxygen content in water

Question 23

what factors affect genetic diversity>

Answer 23

• mutation
• gene flow (two separate populations interbreeding)
• natural selection
• bottlenecks
• founder effect
• genetic drift (random nature of allele inheritance)