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Biology A Level > Biodiversity > Flashcards

Flashcards in Biodiversity Deck (43):
1

Biodiversity

measure of the variation found in the living world

2

Species

individual organisms that are very similar in appearance, anatomy, physiology, biochemistry and genetics. So can interbreed freely to produce fertile offspring.

3

Species Richness

number of plant species

4

Species Evenness

the degree to which species are represented/ how evenly represented the species are (diverse if same amount of each)

5

Random sampling disadvantages

may not cover all areas of the habitat equally, species with low presence may be missed so underestimate biodiversity.

6

What is opportunistic sampling?
what are advantages?
what are disadvantages?

researcher makes sampling decisions based on prior knowledge of which areas contain particular species
easier and quicker than random
biased, large or colourful species may attract researcher, so overestimate

7

What is stratified sampling?
advantages?
disadvantages?

dividing habitat into areas which appear different and sampling each separately.
ensures all different areas are sampled
may over-represent some areas

8

What are types of systematic sampling?
advantages?
disadvantages?

line transects, belt transects
when habitat shows clear gradient in environmental factors like getting drier further from pond
only species on line or within belt are recorded, so underestimate

9

What to be careful with when sampling?

not cause disturbance to habitat

10

What is an interrupted belt transect?

use quadrat at set intervals along line

11

What is a continuous belt transect?

place quadrat beside line and move along line so study band/belt in detail

12

6 ways of catching invertebrates

sweep netting (with stout net, empty on white sheet)

pooter (collect animals before fly away)

knock the branch (white sheet under to catch)

pitfall trap (container in soil, contain little water/scrunched paper, in rain should be sheltered)

tullgren funnel (from leaf litter, light above drives animals down as litter dries/warms, fall through mesh to jar)

light trap (UV light attracts, eventually fall into jar containing alcohol)

13

How to trap small animals

may need license
Longworth trap (human trap, should monitor to release trapped animals)
enables mark-and-recapture technique
total population=no. 1st captured x no. 2nd captured
--------------------------------------------------
no. marked captured on 2nd

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disadvantage of mark-and-recapture technique

animals may learn that trap is harmless and contains food, or may keep away from traps after first capture

15

Locus

the position of an allele (version of a gene) on a chromosome

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Polymorphic gene locus

a locus that has more than two alleles

17

Simpson's index of diversity takes into account both...
D is..
n is..
N is..
a diverse habitat will have a .. value

species richness and species evenness.
D is the letter for it
n is the number of individuals of a particular species
N is the total number of all individuals
high

18

Isolated populations...

have limited genetic diversity so may need conservation

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Genetic diversity is found where...

these is more than one allele for a particular locus

20

You can calculate genetic diversity by...

calculating the number of loci in one individual that are heterozygous (contain two different alleles)
or percentage of loci in the population that have more than one allele

21

Monoculture

a crop consisting of one strain of one species

22

How do humans affect biodiversity?

alter ecosystems to provide us with food
destroy habitats
use Earth's resources
pollute atmosphere

23

What happens when we clear natural vegetation and reduce size of habitats?

It reduces population sizes and so reduces genetic diversity. The species is less able to adapt to changing conditions through evolution.

24

Monoculture is good because... but bad because...
Selective breeding means...

it's easier to harvest
it has limited genetic diversity
reduction in genetic diversity and other breeds become rare and may die out

25

Genetic erosion is...

reduction of genetic diversity of a species

26

Climate change will cause...

migration to a more suitable environment but there are obstructions to the migration like human development, agricultural land, bodies of water and mountain ranges.

27

Keystone species

has disproportionate effect upon environment relative to its abundance. (has massive effect compared to how much there is of it)

28

Soil depletion

the loss of soil fertility caused by removal of minerals by continuous cropping

29

Why is genetic diversity good for us?

genetic diversity of wild species may lead to pharmaceutical products

30

Economic reasons to maintain biodiversity
What other reason is there?

natural ecosystems:
regulate atmosphere and climate
purify and retain fresh water
form and fertilise soil
recycle nutrients
recycle waste
pollinate crops
grow timber, food, fuel
provide medicines

also aesthetic reasons - brings people happiness (scientifically proven)

31

Conservation in situ

carrying out active management to maintain the biodiversity in the natural environment

32

Ways of carrying out conservation in situ

legislation (stop activities like hunting/clearing land)
wildlife reserves

33

3 principles for choosing wildlife reserve

comprehensiveness (how many species in area, what env conditions
adequacy (area large enough for long term)
representativeness (full range of diversity within species?)

34

advantages of in situ
disadvantages

in natural habitat
permanent
allows management
ecologically sustainable land uses - economic benefit
research
can improve/restore area

habitats fragmented, small area not large for survival
population may already lost genetic diversity
conditions that causes endangered still present
area good for poachers and ecotourists who disturb

35

Conservation ex situ
and types

outside normal habitat of species
Zoo, Botanic garden, Seed bank

36

What do zoos do?

breeding endangered species (artificial insemination, IVF, embryo transfer)
conduct research that may benefit species (may research on domestic species/common wild species that similar, to spare endangered species from research)

37

10 advantages and 9 disadvantages of ex situ

protected from predators and poaching
health monitored, medical assistance
populations divided so disaster doesn't kill all
genetic diversity measured
selective breeding increases genetic diversity
increase reproductive success
bred to increase numbers
research is easier
attractions to raise funds for conservation
education

captive population limit genetic diversity
exposed to diseases
outside natural habitat
nutritional issues difficult to manage
animals not behave as normal, reproduction difficult
correct env difficult to achieve
expensive
new have to survive reintroduction to wild
reintroduced animals may struggle with acceptance by existing wild members

38

How do Botanic Gardens work? plus advantages (
seeds
storing
breeding
wild

seeds produced in large numbers and collected form wild without much disturbance
stored (without occupying lots space), germinated in protected place
plants bred asexually and can very quickly increase no.
can replant in wild

39

Botanic Gardens disadvantages (7)

funding (fewer donations)
collecting causes some disturbance
samples may not have representative level of genetic diversity
seeds from one area may be different to others so not succeed in different place
stored seeds may not be viable
asexual breeding reduces genetic diversity
research maybe not valid for whole species

40

How are seeds stored in Seed banks?

dry, freezing conditions
check regularly for viability

41

CITES (The Convention on International Trade in Endangered Species)

international agreement to ensure internatinal trade in specimens of wildlife doesn't threaten their survival.
stops trade for commercial purposes
less endangered species can trade subject to permit

42

Rio Convention on Biological Diversity

sustainable use
shared access to genetic resources
sharing of scientific knowledge and technologies (improve chance of success)
fair sharing of benefits from use of genetic resources

43

The Countryside Stewardship Scheme

encourages landowners to manage land in way that promotes conservation. (funding and advice)