biodiversity Flashcards
define biodiversity
measure of variety of life in an area
define species diversity
no of species and no of individuals within each species in a community
define a species
all organisms that are capable of breeding together to produce living, fertile offspring
define genetic diversity
measure of all the genes possessed by the individuals in a population or whole species
what does courtship allow individuals to do?
recognise members of own species identify mate capable of breeding form a pair bond synchronise mating become able to breed
what is artificial classification?
divides organisms based on differences useful at time
eg colour, number of legs, size which are all ANALOGOUS CHARACTERISTICS
what are analogous characteristics?
same function BUT different evolutionary origin
eg - butterfly and bird wings both for flight but originated in different ways
3 factors of phylogenetic classification
- based on evolutionary relationships between organisms + ancestors
- classifies species into gps using shared features from ancestors
- arranges groups into a hierarchy
what is a hierarchy?
systematic organisation of organisms into levels based on complexity - NO OVERLAP
what are homologous characteristics?
similar evolutionary origins regardless of their functions in adult of species
mnemonic for classification
delicious king prawn curry or fat greasy sausages
3 parts of Domain
bacteria
archaea
eukarya
features of bacteria
no membrane bound organelles unicellular 70s ribosomes MUREIN cell wall no HISTONES
features of archaea
no MUREIN in cell walls
more complex rna polymerase than bacteria
features of eukarya
cells posses membrane bound organelles
not all have cells with cell walls
80s ribosomes
define ecosystem diversity
range of different habitats from a small local habitat to whole earth
define species richness
number of different species in a particular area at a given time
farming practices that reduce species diversity
removal of hedgerows
creating monocultures
filling in ponds + draining marsh
over grazing land
farming practices with indirect effect on species diversity
pesticides
inorganic fertilisers
absence of crop rotation
examples of conservation practices
maintain existing hedgerows (A shape) plant hedgerows as field boundaries maintain existing ponds plant native trees in lands of low species diversity reduce use of pesticides create natural meadows leave cutting of verges til seeds dispersed conservation headlands
give three ways of investigating diversity
compare observable characteristics
compare DNA base sequences
compare mRNA base sequences
limitation of comparing observable characteristics to investigate diversity
large number of characteristics coded for by more than one gene POLYGENIC
characteristics can be modified by the environment
how can comparison of base sequences help investigate diversity?
use gene technology
determine order of nucleotide bases
each base tagged w/ different dye
due to MUTATION - sequence of nucleotide bases in DNA of new species will change — over time the new species will accumulate more differences in DNA
define interspecific variation
one species differs from another
