biodiversity

Question 1

biodiversity definition?

Answer 1

variety of living organisms in an area

Question 2

three levels of biodiversity?

Answer 2

1. Habitat= no. of different habitats in an area
2. Species= species evenness and richness
3. Genetic diversity= variation of alleles within a species or a population of species

Question 3

species richness definition?

Answer 3

number of different species in an area

Question 4

species evenness definition?

Answer 4

the abundance of each species in an area

Question 5

how does random sampling work?

Answer 5

-done to remove bias
-divide area into grid using tape measures
-use random number generator to pick co-ordinates
-this ensures each sample site has the same probability of being chosen

Question 6

three types of non- random sampling and explanation?

Answer 6

1- Systematic sampling= taken at fixed intervals along a line
2- Opportunistic sampling= samples are chosen by investigator, (bias)
3- Stratified sampling= different areas in a habitat selected and sampled separately, in proportion to their part of the habitat as a whole

Question 7

definition of species?

Answer 7

a group of similar organisms, able to reproduce to give fertile offspring

Question 8

what equipment can you sue to sample crawling insects?

Answer 8

pitfall trap- small pit, organisms can’t get out
pooter- insects sucked into jar via tube

Question 9

how to sample for organisms living in long grass?

Answer 9

sweep net- sweep net once from left to right, turn contents into a collecting tray

Question 10

how can the number of organisms in a habitat be estimated using only samples?

Answer 10

calculate mean of the data, multiply this by the size of the whole habitat

Question 11

what indicates a high species evenness?

Answer 11

a similar population size of each species

Question 12

what does high biodiversity rely on?

Answer 12

high species evenness
high species richness

Question 13

What form of species is Simpson’s Index of Diversity used for?

Answer 13

species that are present in a habitat in small numbers

Question 14

what does Simpson’s Index of Diversity measure?

Answer 14

species diversity

Question 15

what is the formula for Simpson’s Index of Diversity?

Answer 15

D= 1 -(total(n/N)2)

Question 16

what does n represent?

Answer 16

total number of organisms of one species

Question 17

what does N represent?

Answer 17

total number of all organisms

Question 18

what indicates a good diversity?

Answer 18

number closer to 1, further from 0

Question 19

what does high genetic diversity lead to?

Answer 19

greater ability to survive and adapt to changes e.g. new predators, disease

Question 20

examples of populations with low genetic diversity?

Answer 20

isolated populations=
-bred in captivity
-pedigree populations
-rare breed

Question 21

what is interbreeding and how is it prevented in zoos?

Answer 21

-breeding between closely related individuals
-prevented in breeding programmes, genetic diversity maximised

Question 22

what is calculating polymorphic gene loci in a population a measure of?

Answer 22

measure of genetic diversity

Question 23

what is polymorphism?

Answer 23

a locus (point on a chromosome) that has two or more alleles

Question 24

formula for calculating proportion of polymorphic gene loci

Answer 24

number of polymorphic gene loci/ total number of loci

Question 25

what 4 factors of human population growth affect biodiversity?

Answer 25

1- habitat loss= more land for housing+ food means habitats are destroyed e.g. deforestation 2- over exploitation= greater demand for resources such as food, energy means resources are used faster than they are replenished e.g. fishing 3- urbanisation= roads/ cities isolate species, unable to interbreed, genetic diversity decreases 4- pollution= more waste& pollution destroys habitats and kills species e.g. fertiliser in rivers kill fish, acid rain

Question 26

what 3 factors are caused by monoculture and lead to decline in biodiversity?

Answer 26

1- habitat loss= habitat diversity decreases, land cleared, as well as parts of sea e.g. shrimp farms clear mangrove forests 2- loss of local plants and animals= destroyed with pesticides, species diversity decreases 3- loss of heritage varieties= traditional crops lost as they don't make enough money

Question 27

climate change definition?

Answer 27

long term change in an area's climate e.g. temperature or rainfall patterns

Question 28

how does climate change affect biodiversity?

Answer 28

changing environmental conditions= - species need a particular climate to survive, an area once inhabitable becomes uninhabitable - range of species/ biodiversity can increase or decrease

Question 29

how is species distribution affected by climate change?

Answer 29

-species migrate to a more suitable area, change in biodiversity occurs. -species may become extinct if it is unable to migrate or adapt= decreases biodiversity

Question 30

three categories of reasons to protect biodiversity?

Answer 30

- economic - aesthetic - ecological

Question 31

ecological reasons to maintain biodiversity?

Answer 31

Protecting species= -distribution of food chains -distribution of nutrient cycles (decomposers improve soil quality) -protecting keystone species Maintaining genetic resources= -crops/ plants used in medicine -fuels, food, clothing, drugs

Question 32

economic reasons to protect biodiversity?

Answer 32

-products derived from plants& animals are traded globally -reducing soil depletion= continuous monoculture causes soil depletion as nutrients in soil are used up. this decreases yield and means more money used on fertiliser

Question 33

aesthetic reasons to maintain biodiversity?

Answer 33

- beautiful landscapes protected -tourism due to landscapes

Question 34

what are keystone species?

Answer 34

species which many other species in an ecosystem depend on, e.g. predators that keep prey population in check

Question 35

ecosystem definition?

Answer 35

all the organisms in an area and all the non living conditions. these are interdependent

Question 36

what is the role of conservation and why is it important?

Answer 36

-to protect and manage species and habitats -ensures the survival of endangered species

Question 37

what is in-situ conservation? (6 examples)

Answer 37

conservation of species in their natural habitat= -protected areas (restricted urban development, farming) -preventing introduction of species that threaten local biodiversity -protecting habitats (coppicing, controlled tree trimming) -restoring damaged areas -legal protection to species -promoting particular species

Question 38

advantages and disadvantaged of in-situ conservation)

Answer 38

a- habitat and species conserved, less disruptive, greater chance of recovery d- can be difficult to control some factors e.g. poaching, disease, predators

Question 39

what is ex-situ conservation? (5 examples)

Answer 39

protecting species by removing p[art of the population= -relocating an organism to a safer area -breeding organisms in captivity, reintroducing to the wild -botanic gardens used to grow rare plants -seed banks, seeds frozen and stored without losing fertility

Question 40

ex-situ advantages and disadvantages?

Answer 40

a- can protect individual animals, predation and hunting managed more easily, competition is reduced, treat for diseases, breeding for characteristics can be manipulated d- small no. of individuals cared for, right environment hard to create, expensive, disease from humans, don't adapt to new location

Question 41

two examples of international co-operation on conservation?

Answer 41

Rio Convention on Biological Diversity (CBD)= how to sue animals and plants resources sustainably, guidance on how to protect biodiversity CITES agreement= illegal to kill endangered species, trade in resources from endangered species

Question 42

example of local conservation agreement?

Answer 42

The Countryside Stewardship Scheme= conserve wildlife and biodiversity. 10 year agreements to pay landowners who agreed to terms e.g. regenerate hedgerows