4.2.1 - Biodiversity

Question 1

What is biodiversity?

Answer 1

the variety of living organisms in an area

Question 2

What is the relationship between biodiversity and the stability of an ecosystem?

Answer 2

proportional to eachother

-more biodiversity there is, the more stable the ecosystem is

Question 3

What different levels can biodiversity be considered on?

Answer 3

• habitat biodiversity (e.g. sand dunes, woodland, meadows, streams)
• species biodiversity (species richness and species evenness)
• genetic biodiversity (e.g. different breeds within a species)

Question 4

What is habitat biodiversity?

Answer 4

the number of different organisms in an area

Question 5

What is species biodiversity?

Answer 5

species richness (number of different species living in an area)
species evenness (abundance of each species -comparison between the number of each different species)

Question 6

What is sampling?

Answer 6

taking measurements of individual organisms present in a particular area

Question 7

What is random sampling?

Answer 7

selecting individuals by chance

-each individual in the population has an equal likelihood of being selected

Question 8

What is non-random sampling?

Answer 8

sample is not chosen by random

• opportunistic: uses organisms that are available conveniently at the time
• stratified: population is divided into sub groups and then a random sample is taken from each sub group proportional to its size
• systematic: different areas within an overall habitat are sampled separately

Question 9

What is opportunistic sampling?

Answer 9

a type of non-random sampling where organisms that are conveniently available at the time are used

Question 10

What is stratified sampling?

Answer 10

a type of non-random sampling where populations are divided into strata (sub groups) based on a characteristic and then a random sample is take from each strata proportional to its size

Question 11

What is systematic sampling?

Answer 11

a type of non-random sampling where different areas within an overall habitat are identified and then sampled separately
-usually carried out by using a line or belt transect (quadrat moved along line

Question 12

Name some sampling techniques for animals

Answer 12

• pooter (insects)
• sweep nets (insects in areas of long grass)
• pitfall traps (small, crawling invertebrates)
• tree beating (invertebrates in trees/bushes)
• kick sampling (organisms living in water)
• tullgren funnel (organisms in soil)

Question 13

Name some sampling techniques for plants

Answer 13

• point quadrats

- frame quadrats

Question 14

How do you increase the reliability of sampling?

Answer 14

• taking a large number of samples at a number of different points
• use random sampling (to reduce bias)

Question 15

What is Simpsons index of biodiversity?

Answer 15

a better measure of biodiversity that takes species richness and evenness into account

Question 16

What does a low/high value from Simpsons index of biodiversity mean?

Answer 16

0 = no diversity
1 = infinite diversity
(closer to 0 = lower biodiversity, closer to 1 = higher biodiversity)

Question 17

How does genetic biodiversity occur within a species?

Answer 17

• there is little variation of DNA within a species
• all members have the same gene but different alleles
• differences in alleles creates genetic biodiversity
• more alleles present, the more genetically biodiverse a population

Question 18

proportion of polymorphic gene loci (%) =

Answer 18

number of polymorphic gene loci
__________________________
total number of loci

Question 19

What factors decrease genetic biodiversity?

Answer 19

• artificial cloning
• selective breeding
• captive breeding programmes
• rare breeds
• natural selection
• genetic bottlenecks
• the founder effect
• genetic drift

Question 20

What factors increase genetic biodiversity?

Answer 20

• interbreeding

- mutations

Question 21

What are polymorphic genes?

Answer 21

genes that have more than one allele

-the more polymorphic genes a species has, the more genetically biodiverse the species is

Question 22

What factors affect biodiversity?

Answer 22

• human population growth
• agriculture (monoculture, chemicals, etc)
• climate change

Question 23

What is monoculture?

Answer 23

when a large amount of biodiverse land is cleared and a single crop is plants

• only one species present
• less animal species can be supported (less food sources)

Question 24

What reasons are there for biodiversity to be maintained?

Answer 24

• ecological (eg. protecting keystone species, maintaining genetic resources)
• economic (eg. reducing soil depletion from continuous monoculture)
• aesthetic (eg. protecting landscapes)

Question 25

What are keystone species?

Answer 25

species that have a disproportionately large effect on their environment relative to their abundance

• affect many other organisms in an ecosystem and help determine species richness and evenness
  eg. sea star

Question 26

What is conservation?

Answer 26

the preservation and careful management of the environment and natural resources

Question 27

What are the two types of conservation?

Answer 27

• in situ (in natural habitat)

- ex situ (not in natural habitat)

Question 28

What is in situ conservation?

Answer 28

conservation in natural habitat

eg. wildlife preserve

Question 29

What is ex situ conservation?

Answer 29

conservation not in natural habitat

eg. zoo

Question 30

Name some examples of in situ conservation

Answer 30

marine conservation zones

wildlife reserves

Question 31

Name some examples of ex situ conservation

Answer 31

seed banks
botanic gardens
zoos

Question 32

Name some conservation agreements

Answer 32

• the Convention on International Trade in Endangered Species (CITES)
• the Rio Convention on Biological Diversity (CBD)
• the Countryside Stewardship Scheme (CSS)

Question 33

What does Convention on International Trade in Endangered Species (CITES) do?

Answer 33

• issues an annual red list (conservation status of threatened animals) -makes it illegal to kill endangered species
• regulates trade of plant and animals species and their products -limits trade through licensing

Question 34

What does the Rio Convention on Biological Diversity do?

Answer 34

• aims to develop international strategies on the conservation of biodiversity and how to use plant and animal resources in a sustainable way
• develop strategies on sustainable development
• stabilises greenhouse gas concentrations in the atmosphere
• aims to prevent transformation of fertile land into desert and reduce the effects of drought

Question 35

What does the Countryside Stewardship Scheme (CSS) do?

Answer 35

• government pays land managers (like farmers) to enhance and conserve the English landscape
• sustaining the beauty and diversity of the landscape
• improving, extending and creating wildlife habitats
• restoring neglected land
• conserving archaeological and historic features
• improving opportunities for countryside development

Question 36

What are the advantages of conserving plants as seeds compared to as adult plants?

Answer 36

• can be collected with minimal damage to wild population
• takes up little space
• can store greater genetic diversity
• lower maintenance
• easy to transport
• viable for long periods
• less susceptible to disease/environmental change
• prevents fertilisation by undesired pollen

Question 37

Why is sampling important in measuring the biodiversity of a habitat?

Answer 37

• it is difficult to count every individual so sampling provides an estimate
• sample is representative of whole area