deck_13003253 Flashcards
What is a species?
a group of individual organisms with similar characteristics that can breed to produce fertile offspring
What is a habitat?
the natural home or environment of a species
What is biodiversity?
the variety of organisms/species present in an area
What are the types of biodiversity?
Genetic
Habitat
Species
Describe genetic biodiversity?
Variety of genes found in individuals in a species
Describe habitat biodiversity
the range of habitats in an area
Describe species biodiversity
species richness: # of species in an area
species evenness: number of individuals within a species in an area
Define population
all the organisms of a particular species found in an ecosystem
Define community
Populations of all species found in a particular ecosystem
Define ecosystem
system of organisms interacting with each other and the environment
Define abiotic/biotic
abiotic: non-living components (environmental)
biotic: living components
Define sampling
measurement of abundance and distribution of species in an area
Define random sampling
non-biased way of sampling where every individual has an equal likelihood of selection
allows estimation of population
Why is it important for samples to be random?
removes bias therefore making sample more reliable
What are the 3 types of non-random sampling?
Opportunistic
Stratified
Systematic
Describe stratified sampling
dividing populations into strata (sub-groups) based on characteristics
eg. male and female
Describe systematic sampling
used when there is a clear change in different areas of habitat using a line/belt transect
Describe opportunistic sampling
selecting organisms that are conveniently available to the experimenter
Describe kick-sampling
disturbing substrate in river banks to release organisms where they are captured downstream
Describe sweep netting
sweeping a net in long wild grass to catch flying invertebrates
Describe pitfall traps
a hole in soil deep to catch vertebrates covered to stop rainwater entering
Describe tree-beating
laying large cloth out and beating a tree to knock organisms and catch them in the cloth
Describe a pooter
glass container used to suck small organisms - filter covers one tube to stop organisms being sucked into mouth
Describe species evenness
the number of organisms within a species in an area
Describe species richness
the number of species present in an area
What are genetic causes for loss/gain of biodiversity?
+ mutations
+ interbreeding
- selective breeding
- captive breeding
- cloning
- genetic drift
- natural selection
- genetic bottleneck (catastrophic event)
Define abiotic factors
non-living components of an ecosystem
- temperature
- pH
- humidity
- light
- water