4.2.1 biodiversity

Question 1

biodiversity

Answer 1

measure of variation found within living world

Question 2

habitat

Answer 2

where an organism lives

Question 3

species

Answer 3

group of organisms which can freely interbreed to produce fertile offspring

Question 4

what is biodiversity a measure of

Answer 4

all the different plant, animal, fungus & other microorganism species worldwide, the genes they contain & the ecosystems of which they form a part

Question 5

habitat biodiversity

Answer 5

place where individual species live & the range of habitats in which different species live
- each habitat will be occupied by range of organisms

Question 6

species biodiversity

Answer 6

species = individual organisms which are very similar in appearance, anatomy, physiology, biochemistry & genetics
- can interbreed freely to produce fertile offspring
- range of organisms in a habitat contributes
- 2 habitats may have equal number of species but may not be considered equally diverse

Question 7

species richness

Answer 7

number of species

Question 8

species evenness

Answer 8

degree to which the species are represented

Question 9

genetic biodiversity

Answer 9

• variation between individuals belonging to the same species
• ensures we don’t all look identical
• can create breeds within a species

Question 10

what is required to measure the biodiversity of a habitat

Answer 10

• observe all species present
• identify species
• count how many individuals of each species

Question 11

what is sampling a habitat

Answer 11

select small portion & study it
–> can multiply up numbers of individuals found to estimate number in whole habitat

Question 12

what must the samples be

Answer 12

representative of the habitat

Question 13

name 2 main sampling techniques

Answer 13

• random
• non-random

Question 14

what is non-random sampling split into

Answer 14

• opportunistic
• stratified
• systematic

Question 15

how is random sampling carried out

Answer 15

sample sites in habitat randomly selected:
- can be achieved by using randomly generated numbers as coordinates
OR
- selecting coordinates on map & using portable global positioning satellite system to find exact position in habitat

Question 16

advantages of random sampling

Answer 16

• ensures data isn’t bias by selective sampling

Question 17

disadvantages of random sampling

Answer 17

• may not cover all areas equally
• species of low presence may be missed = underestimate of biodiversity

Question 18

how is (non-random sampling) opportunistic sampling carried out

Answer 18

• researcher makes sampling decisions based on prior knowledge or during process of collecting data
• researcher may deliberately sample area they know/can see contains a particular species

Question 19

advantages of (non-random sampling) opportunistic sampling

Answer 19

• easier & quicker than random sampling

Question 20

disadvantages of (non-random sampling) opportunistic sampling

Answer 20

• data may be biased
  –> presence of large/colourful species may entice researcher to include the species
  = may lead to overestimate of importance & thus, overestimate of biodiversity

Question 21

how is (non-random sampling) stratified sampling carried out

Answer 21

• divide habitat into areas which appear different
• sample each area separately
  eg. patches of bracken in heathland sampled separately from heather/gorse patches

Question 22

advantages of (non-random sampling) stratified sampling

Answer 22

• ensures all different areas of habitat are sampled
• ensures species aren’t under-represented due to possibility that random sampling misses certain areas

Question 23

disadvantages of (non-random sampling) stratified sampling

Answer 23

• possibility it will lead to over-representation of some areas in sample eg. disproportionate number of samples taken in small areas which look different

Question 24

how is (non-random sampling) systematic sampling carried out

Answer 24

• samples taken at fixed intervals across habitat
• line transects/belt transects are systematic techniques

Question 25

advantages of (non-random sampling) systematic sampling

Answer 25

• particularly useful when habitat shows clear gradient in some environmental factor eg. getting drier further from pond

Question 26

disadvantages of (non-random sampling) systematic sampling

Answer 26

• only species on line/within belt can be recorded
• other species may be missed = underestimate in biodiversity