4.2.1 Biodiversity

Question 1

ecosystem

Answer 1

all members of all species + their environment
(abiotic factors)

Question 2

ecosystems with high biodiversity

Answer 2

rainforests
woodlands
coral reefs

Question 3

ecosystems with low biodiversity

Answer 3

desert
tundra

Question 4

habitat

Answer 4

a place where organisms live

Question 5

community

Answer 5

multiple species and their interactions in an ecosystem

Question 6

species

Answer 6

a group of organisms which can interbreed to produce fertile offspring

Question 7

population

Answer 7

all members of the same species living in a habitat

Question 8

variation

Answer 8

differences due to genes and environment

Question 9

intraspecific variation

Answer 9

differences within a species

Question 10

interspecific variation

Answer 10

differences between species

Question 11

three strands of biodiversity

Answer 11

ecosystem diversity
species diversity
genetic diversity

Question 12

species that lack genetic diversity due to isolation or low population numbers are more vulnerable to fluctuation due to what factors?

Answer 12

climate change
disease
habitat fragmentation

Question 13

what do coral reefs provide to organisms within the ecosystem

Answer 13

microhabitats
shelters
breeding grounds/nesting sites

Question 14

keystone organism

Answer 14

many others depend on for survival
have a disproportionate effect on other species

Question 15

three levels of biodiversity

Answer 15

range of habitats/microhabitats in an ecosystem
range of species within each ecosystem
range of genes/alleles within each species

Question 16

ex situ

Answer 16

out of natural habitat

Question 17

in situ

Answer 17

in natural habitat

Question 18

ecosystem/habitat biodiversity

Answer 18

the variety of ecosystems in an area
the variety of habitats within an ecosystem

Question 19

species biodiversity

Answer 19

the variety of species within an ecosystem or habitat

Question 20

2 levels of species biodiversity

Answer 20

species richness
species evenness

Question 21

species richness

Answer 21

the number of different species in an ecosystem

Question 22

species evenness

Answer 22

the relative number of individuals of each species

Question 23

genetic biodiversity

Answer 23

the variety of genes in a gene pool for a particular species

Question 24

a gene

Answer 24

a sequence of DNA bases that codes for a specific amino acid sequence

Question 25

what determines genetic diversity

Answer 25

variety and frequency of different alleles in a population

Question 26

methods to calculate genetic diversity

Answer 26

proportion of polymorphic genes
proportion of heterozygous genes
proportion of genes that are homozygous recessive

Question 27

proportion of polymorphic genes =

Answer 27

number of polymorphic genes/ number of genes studied

Question 28

factors affecting biodiversity

Answer 28

deforestation
destruction of coral reefs
destruction of the sea bed
overexploitation
overhunting
agriculture
pollution from agriculture
climate change

Question 29

causes of deforestation

Answer 29

clearing for; agriculture, housing, timber

Question 30

effects of deforestation

Answer 30

loss of species and loss of resources to rebuild number of species
habitat destruction
decreases species diversity

Question 31

causes of destruction of coral reefs

Answer 31

farming, fishing, leisure activity

Question 32

effects of destruction of coral reefs

Answer 32

loss of species and loss of resources to rebuild number of species
habitat destruction
decreases species diversity

Question 33

causes of destruction of the sea bed

Answer 33

dragnets scrape the sea bed

Question 34

effects of destruction of the sea bed

Answer 34

loss of species and loss of resources to rebuild number of species
habitat destruction
decreases species diversity

Question 35

causes of overexploitation

Answer 35

removal of timber for industry or furniture; overfishing so fish stock falls

Question 36

effects of overexploitation

Answer 36

reduction in the number of species and loss of habitat

Question 37

causes of overhunting

Answer 37

removal of wild animals as ‘bush meat’

Question 38

effects of overhunting

Answer 38

species at risk of extinction - genetic bottlenecks

Question 39

causes of agriculture

Answer 39

monoculture of one type of crop or livestock

Question 40

effects of agriculture

Answer 40

reduction in the number of a particular species - reduces species evenness

Question 41

causes of pollution from agriculture

Answer 41

waste; use of fertilisers and pesticides - bioaccumulation

Question 42

effects of pollution from agriculture

Answer 42

loss of species diversity as some species thrive with additional fertilisers and others are destroyed; runoff pollutes streams and pond water

Question 43

causes of climate change

Answer 43

modification of weather patterns such as drought and floods affecting species distribution

Question 44

effects of climate change

Answer 44

distribution of species change; lack of food for some species causes decline

Question 45

sampling

Answer 45

taking measurements of a limited number of individuals in a particular area
used to estimate the number/frequency/density of organisms in an area without having to count them

Question 46

how to measure species richness

Answer 46

count the number of different species present

Question 47

how to measure species evenness

Answer 47

count the number of different species present and the number of individuals of each species