Biodiversity 2

Question 1

Why maintain biodiversity

Answer 1

Provide resources such as food and medical uses
Protect food webs maintain ecosystem
Aesthetic reasons
Reduce ability to grow crops - soil erosion from deforestation
High biodiversity protects against abiotic stresses

Question 2

Why are monocultures bad

Answer 2

1 species same field lacking biodiversity more susceptible to disease
Leach off soil for nutrients and minerals
Efficient
Must rotate to improve quality of soil

Question 3

CSS

Answer 3

Farmers have a grant from government to make land more biodiverse

Question 4

CITES

Answer 4

Prevention of trade of exotic animals or those at risk of extinction

Question 5

Rio convention

Answer 5

All development requires an environmental impact assessment

Question 6

Ways biodiversity can be studied

Answer 6

Habitat biodiversity
Species biodiversity
Genetic biodiversity

Question 7

Habitat biodiversity

Answer 7

No of different habitats that can be found within an area - greater the habitat biodiversity greater species biodiversity

Question 8

Species biodiversity

Answer 8

-species richness - number of different species in an area
- species evenness - comparison of the numbers of individuals of each species living in a community

Question 9

Genetic biodiversity

Answer 9

Variety of genes that make up a species
Species have the same number of genes however different alleles leads to genetic biodiversity within a species
More biodiverse better adapted to changing environment

Question 10

Sampling techniques

Answer 10

Random - at chance (mark out grid random number generator coordinates)
Opportunistic - organisms conveniently available
Stratified - population divided into subgroups and random sample of these proportion to size
Systematic - line transect or belt transect - studland bay

Question 11

Reliability of samples

Answer 11

Never entirely representative
Sampling bias - selection process may be bias - use random sampling
Chance - organism selected may not be representative of whole population - minimised by using a large sample size

Question 12

Sampling animal techniques

Answer 12

Pooter - catch small insects
Sweep nets - catch insects in long grass
Pitfall traps - catch small crawling invertebrates
Tree beating - samples of invertebrates in tree
Kick sampling- river bank and bed kicked to disrupt substrate and organisms

Question 13

Estimating animal population size

Answer 13

Capture mark release recapture
Greater the number of marked recaptured smaller the population size

Question 14

Measuring abiotic factors

Answer 14

Can be measured quickly and accurately with specialised equipment eg pH probe
Human error is reduced
High level of precision
Data can be stored and tracked on a computer

Question 15

How to calculate biodiversity

Answer 15

Simpsons index= 1-sum of (total no of a particular species/total number of all organism of all species)^2

Question 16

Simpsons index value

Answer 16

0 represents no diversity and 1 represents infinite biodiversity
The higher the value the more diverse the habitat

Question 17

Low biodiversity values

Answer 17

Low biodiversity habitats may not be able to support many species the ones present may be highly adapted to extreme environment
Important to conserve these habitats in order to conserve rare species that may not cope elsewhere

Question 18

Importance of genetic biodiversity

Answer 18

Greater genetic biodiversity likely to adapt to changes in their environment less likely to become extinct
More likely some organisms carry an advantageous allele which enables them to survive

Question 19

Factors that increase genetic biodiversity

Answer 19

Mutation in dna creating new alleles
Interbreeding between different populations- gene flow

Question 20

Factors that decrease genetic biodiversity

Answer 20

Selective breeding
Captive breeding programs
Artificial cloning
Natural selection
Genetic bottlenecks - pop died reducing gene pool only survivors able to pass on genes
Founder effect - geographically isolated small gene pool
Genetic drift

Question 21

Polymorphic genes

Answer 21

More than one allele
Proportion = no of poly gene loci/ total No of loci
Greater proportion greater genetic biodiv

Question 22

Human influence on biodiversity

Answer 22

Deforestation - permanent removal of trees to provide wood and make space for building etc
Agriculture - land cleared and planted with monoculture
Climate change - release of CO2 and other greenhouse gases incr temp of planet damaging habitats

Question 23

Positive human activity

Answer 23

Grazing animals planting hedges and managing woodland sheep grazing on down lands - maintains species survivals grass low level allows insects to survive

Question 24

Maintaining biodiversity

Answer 24

In situ conservation - within natural
Ex situ conservation - out of natural

Question 25

In situ

Answer 25

Wildlife reserves- control grazing human activity poaching halting succession removal of invasive species Marine conservation zones prevent fishing in the area and build up populations

Question 26

Ex situ

Answer 26

Botanic gardens Seed banks - gene banks Captive breeding programmes (Some can’t be released into wild due to lack of resistance to disease behaviour genetic differences and habitat change)