M4 CH11: biodiversity Flashcards
define biodiversity
the variety of living organisms in a specific area
define habitat biodiversity
the number of different habitats in a given area
define species richness
the number of different species living in a particular area
define species evenness
the relative abundance of individuals of each species
define genetic biodiversity
the variety of alleles within a species
explain what genetic drift is
the loss of diversity over time by random chance
outline the importance of genetic diversity
creates a larger gene pool
more adaptations and survivals
resistance to biotic factors- disease
explain what a locus is
the position of a gene on a chromosome
explain the term natural selection
- reproduction creates more individuals than the environment can support.
- competition for food occurs as a consequence
- limited food acts as a selection pressure for organisms
- individuals with favourable phenotypes have a selective advantage
- these organisms outcompete others for food, and survive and reproduce
- these favourable alleles are passed onto future generations
state 3 causes of low genetic diversity.
- genetic bottleneck event
- the founder effect
- genetic drift
state the factors affecting genetic biodiversity.
mutations
natural selection
genetic bottlenecks
founder effect
genetic drift
gene flow
explain what a genetic bottleneck is.
natural disaster
causes a large decrease in population size
reduces the gene pool
results in reduced genetic variation
explain what the founder effect
when a few individuals of a species take over a new area, their offspring experience a loss in genetic variation. this results in rarer alleles becoming more common in the population.
explain what genetic drift is
random fluctuations in the frequencies of alleles between generations
can cause some traits to become dominant, some to disappear
explain why genetic drift is more pronounced in small populations.
because the gene pool is smaller
explain what gene flow is
the transfer of alleles from one population to another when individuals of one population migrate
state some human activities which have changed the genetic diversity of organisms
selective breeding
captive breeding
cloning
explain what genetic polymorphism is
genes which have multiple alleles
explain what a polymorphic gene is
a gene with more than one allele
synoptic: state the name of the process that can be used to separate DNA fragments based on their size. explain the process.
electrophoresis
add expln
give the equation to calculate the proportion of polymorphic gene loci
number of polymorphic loci / total number of loci
state the 2 types of sampling that can be used.
random
non random
state the most appropriate equipment to gather a random sampling of flying organisms
sweeping nets
explain what pitfall traps are
what type of sampling
what organisms are gathered in them
cans/jars buried in the ground
random sampling method
small ground-bound organisms
explain what pooters are
what type of sampling
what organisms are gathered in them
plastic/glass containers, 2 tubes sticking out of them. suction mechanism to gather
random sampling
INSECTS
explain what a tullgren funnel is
type of sampling
organisms gathered
funnel with light bulb above & container below- used for soil samples
random sampling
invertebrates living in soil
explain what kick sampling is
type of sampling
organisms gathered
net placed on stream bed in aquatic ecosystems
random sampling
aquatic organisms
Queen of Sampling Plays Poker Till King comes home
write out acronym, apply and explain (linked to biodiversity)
random sampling methods
quadrat- plant sampling
sweeping nets: flying insects/long grass samples
pitfall traps: ground jars- insects on ground
pooters: suction mechanism: insects
tullgren funnel: for soil samples/ light bulb and funnel
kick sampling: net on stream bed (aquatic sampling)
describe opportunistic sampling (3)
non random sampling
picking and choosing sampling locations
usually dictated by convenience
describe stratified sampling. (2)
non random sampling
dividing up area for sampling
done when there is habitat variety- sample sizes are proportional to the proportion of each habitat relative to the whole area
describe when you would use systematic sampling
when there is a clear change in the conditions as you move across the area
describe the 2 types of systematic sampling
line transect: tape measure, recording at equal distances
belt transect: quadrats placed at regular interval across the length of the area
line transect:
random or non random?
systematic, opportunistic or stratified?
qualitative or quantitative?
non random
systematic
qualitative
belt transect:
random or non random?
systematic, opportunistic or stratified?
qualitative or quantitative?
non random
systematic
quantitative
what information does a belt transect give that random quadrat sampling does not
records the change as you move across the area (systematic) as oppose to random points in the area
describe how to use a random frame quadrat
place quadrat randomly in area using co ordinates (to ensure completely random)
count species richness and evenness
(n/of species, n/of each species)
