4.2.2: biodiversity

Question 1

what is meant by biodiversity?

Answer 1

the variety of living organisms present in an area

Question 2

what are the 3 different ways in which biodiversity can be studied?

Answer 2

• habitat biodiversity (sand duns, woodland, meadows, streams)
• species biodiversity (species richness and species evenness)
• genetic biodiversity (different breeds within a species)

Question 3

what is species richness?

Answer 3

the number of different species living in a particular area

Question 4

what is species evenness?

Answer 4

a comparison of individuals in each species in a community

Question 5

what is meant by genetic biodiversity?

Answer 5

refers to the variety of genes that make up a species

Question 6

what is sampling?

Answer 6

taking measurements of a limited number of individuals in a certain area

Question 7

what is the method for random sampling?

Answer 7

selecting individuals by chance:
- mark out a grid on the area, use a random no. generator to determine the x and y co-ordinates
- take a sample from the co-ordinates generated

Question 8

what is opportunistic sampling?

Answer 8

(not representative of population) use organisms that are conveniently available

Question 9

what is stratified sampling?

Answer 9

population divided into strata (sub-groups) based on particular characteristic (e.g. separating males and females)

Question 10

what is systematic sampling?

Answer 10

diff areas within an overall habitat are identified, which are then samples separately
- line transect
- belt transect (sample taken from between the two lines)

Question 11

how does a point quadrat work?

Answer 11

• frame with horizontal bar, push pins in at different intervals
• record each species of plant in the pin touches

Question 12

how does a frame quadrat work?

Answer 12

consists of a square frame, divided into equal sections
the type and number of each species within the sections is recorded

Question 13

what are 6 abiotic factors?

Answer 13

• wind speed
• light intensity
• relative humidity
• ph
• temperature
• oxygen content in water

Question 14

how is biodiversity calculated?

Answer 14

• Using Simpson’s Index
• D = 1 - total (total number of organisms of all species / total number of organisms in particular species
• 1 = infinite biodiversity
• 0 = no biodiversity

Question 15

what are the factors that affect genetic biodiversity?

Answer 15

increase:
- mutations
- interbreeding between different populations
decrease:
- selective breeding
- rare breeding
- natural selection
- genetic bottleneck
- founder effect

Question 16

what is meant by genetic bottleneck?

Answer 16

where only few individuals survive an event or change, reduces gene pool for further populations

Question 17

what is meant by the founder effect?

Answer 17

where a small number of individuals create a new colony, geographically isolated

Question 18

how does deforestation effect biodiversity?

Answer 18

• reduces the number of trees
• if only a specific type of tree is felled
• destroys habitats and food sources for other animals
• animals migrate = increase biodiversity in other areas

Question 19

how does agriculture affect biodiversity?

Answer 19

• deforestation to clear land
• removal of hedgerows = less plant species
• pesticides reduce pests
• herbicides reduce plant species in an area
• monoculture = less biodiversity

Question 20

how does climate change affect biodiversity?

Answer 20

• melting of polar ice caps = loss of plant and animals species
• rising sea levels = reducing terrestrial habitats
• higher temperatures and less rainfall = less plants survive
• insect life cycles will change (important pollinators)

Question 21

what are 2 aesthetic reasons for maintaining biodiversity?

Answer 21

• enriches our lives
• patients recover more rapidly from stress and injury when supported by plants

Question 22

what are 2 economic reasons for maintaining biodiversity?

Answer 22

• soil erosion and desertification of land = can’t grow crops
• some species of plant may be medically useful

Question 23

what are 2 ecological reasons for maintaining biodiversity?

Answer 23

• all organisms are interdependent
• some species are keystone species (maintain structure of an ecological community)

Question 24

what is in situ conservation?

Answer 24

takes place within an organisms natural habitat
- wildlife reserves
- marine conservation zones

Question 25

what is ex situ conservation?

Answer 25

the removal of an organism from its natural habitat
- botanic gardens
- seed banks
- captive breeding programmes

Question 26

what is the international agreement titled cites?

Answer 26

• convention on international trade in endangered species
• regulates trade of wild plant and animal specimens and their products

Question 27

what is the international agreement titled cbd?

Answer 27

• the convention on biological diversity
• countries to develop national strategies for sustainable development to maintain biodiversity

Question 28

what is the local agreement titled css?

Answer 28

• the countryside stewardship scheme
• offered governmental payments to farmers and other land managers to to enhance and conserve the english landscape
• sustaining beauty and diversity of the landscape
• improving, extending and creating wildlife habitats
• restoring neglected land
• improving opportunities for countryside enjoyment