Biodiversity

Question 1

Biodiversity

Answer 1

measure of variation found in the living world

Question 2

3 types of biodiversity

Answer 2

Habitat
-range of different habitats in which different species live
Species
-range of organisms found in a habitat
-measured by species richness and evenness
Genetic
-variation between individuals belonging to the same species

Question 3

Types of sampling to measure biodiversity of a habitat

Answer 3

Random
Non random- opportunistic, stratified, systematic

Question 4

Random sampling

Answer 4

-done by creating a grid with coordinates and using random number generator
Advantage- ensures data isn’t biased by selective sampling
Disadvantage- may not cover all areas of the habitat equally

Question 5

Opportunistic sampling

Answer 5

-researcher makes sampling decisions based on prior knowledge eg. choosing an area that contains specific species
Advantage- easier and quicker than random
Disadvantage- may be biased as researcher chooses location

Question 6

Stratified sampling

Answer 6

-dividing a habitat into areas that appear different and sampling each separately
Advantage- ensures all areas of habitat are sampled, so no species missed
Disadvantage- may lead to over-representation of some areas in the sample

Question 7

Systematic sampling

Answer 7

-samples taken at fixed intervals across the habitat (line/ belt transect)
Advantage- useful when the habitat shows a clear gradient in environmental factors eg. distance from pond
Disadvantage- species may be missed as only species on the line can be counted

Question 8

Sampling plants

Answer 8

-quadrats- estimate the percentage cover as quadrats divided into 100 squares
-point frame- frame with needles, count any species touching the needle and calculate percentage cover
Transect
-line- record plants touching the line at regular intervals
-interrupted belt transect- use quadrats at set intervals along the line
-continuous belt transect- place quadrat beside the line and move it along the line

Question 9

Catching invertebrates

Answer 9

-sweep netting- walk through habitat with a stout net and sweep through areas of vegetation.
-pitfall trap- small container buried in soil so only rim is below surface. Animals moving through leaves will fall into the container
-light trap- trap flying insects at night. Insects are attracted to light and will fall into ethanol

Question 10

Trapping small mammals

Answer 10

-use a longworth trap and use mark and recapture technique
Mark recapture technique
-capture a sample of animals
-mark each individual, the number captured = C1
-release marked animals and leaves traps for period of time
-number of animals captured on the second occasion= C2
-number of already marked animals captured= C3
total population= C1xC2/ C3

Question 11

Simpsons index of diversity

Answer 11

D= 1- [sum of (n/N)^2]
n= number of individuals of a particular species
N= total number of all individuals of all species
-high value of simpsons index= high diversity

Question 12

Measuring genetic diversity

Answer 12

Genetic diversity= found when more than one allele for a particular locus
-look at physical characteristics

Question 13

Calculating genetic diversity

Answer 13

-calculate the number of loci in heterozygotes
-calculate the percentage of loci that have more than one allele
-polymorphic gene loci- a locus with more than 2 alleles

Question 14

Factors affecting biodiversity

Answer 14

-Human population growth- exploit environment for food, resources, pollution
-agriculture- uses monoculture and selective breeding. Large areas of land is cleared for agriculture
-climate change- species that aren’t able to adapt to changes are dying, decreasing population and genetic diversity
-extinction

Question 15

Ecological reasons to maintain biodiversity

Answer 15

Interdependence of organisms
-ecosystems are complex as species have evolved to live with each other and depend on each other
-all animals linked within food chain/ web
-when one species is affected by human activities, other species will also be affected (keystone species)
Genetic resource
-if biodiversity declines, genetic diversity declines
-this means we could lose the natural solutions to our problems eg. medicines, vaccines

Question 16

Keystone species

Answer 16

-one that has a disproportionate effect on the environment relative to its abundance
-a decline of keystone species will have a dramatic effect on the habitat
eg. beavers and their dams can cause large areas to flood, creating still water for other species to live

Question 17

Economic reasons to maintain biodiversity

Answer 17

-regulate atmosphere and climate
-purification and retention of fresh water
-fertilisation of soil
-recycling nutrients
-detoxification
-crop pollination
-growth of timber, food, fuel

Question 18

Aesthetic reasons to maintain biodiversity

Answer 18

-experience a feeling of joy and wellbeing when seeing variations of nature
eg. patients recover quicker form stress when exposed to natural environment

Question 19

Conservation in situ

Answer 19

-carrying out active management to maintain biodiversity in the natural environment
-legislation- pass legislation to make hunting/ logging illegal
-wildlife reserves

Question 20

Advantages and disadvantages of conservation in situ

Answer 20

Advantges
-conserved natural enviro
-permanently protects biodiversity
-areas managed to ensure ecological integrity is maintained
-facilitates research
Disadvantages
-population may have already lost much of its genetic diversity
-conditions that caused and the species to become endangered may still be present
-can act as a ‘honeypot’ for poachers

Question 21

Wildlife reserves

Answer 21

-designated areas for the conservation of habitats and species
Principles for choosing a wildlife reserve:
-comprehensiveness-how many species present and enviro conditions
-adequacy- large enough
-representativeness- full range of diversity

Question 22

Conservation ex situ

Answer 22

-conservation outside the normal habitat of the species
-Zoos- captive breeding, breed endangered species, conduct research
-Botanic gardens- conservation of plants
-seed banks- collection of seed samples that are viable for decades

Question 23

Advantages and disadvantages of ex situ conservation

Answer 23

Advantages
-protected from poaching and predators
-health can be monitored
-measure genetic diversity
-selective breeding to increase genetic diversity
Disadvantages
-limited genetic diversity
-exposed to a wide range of diseases
-outside natural habitat
-expensive to maintain suitable conditions

Question 24

CITES aims

Answer 24

Convention of international trade in endangered species
-regulate and monitor international trade in selected species
-ensure international trade doesn’t endanger survival
-trade in wild plants for commercial uses is prohibited

Question 25

Rio convention on biological diversity aims

Answer 25

-conserve biodiversity
-sustainable use of components
-shared access to genetic resources
-sharing of scientific knowledge

Question 26

Local conservation scheme

Answer 26

Countryside stewardship scheme
-improve natural beauty and diversity of countryside
-enhance and restore landscapes with wildlife habitats
-improve opportunities for public access