Classification Flashcards
(23 cards)
What is a species?
A group of individuals that are similar, and can reproduce together to make living, fertile offspring.
Members of the same species occupy the same ecological niches (role and position a species has in its environment).
If a species has 63 chromosomes why would it be infertile?
They have an odd diploid number of chromosomes, so the homologous pairs cannot separate correctly during meiosis to form gametes.
What is courtship behavior?
. actions carried out that are recognized by members of the same species
. ensures that individuals DNA is passed on to the next generation
. ensures mating is successful
How does courtship work?
. males carry out an action- this stimulates the female
. females response stimulates the male to carry out further action
. this is a stimulus-response chain
. this allows the males to determine if the female is receptive to mating
Why is courtship important?
. enables individuals to recognize members of their own species
. identify a mate capable of breeding
. form a pair bond to lead to successful mating and raising of offspring
. synchronize mating to maximum chance o conception
. become able to breed by bringing a member of the opposite sex into physiological state that allows breeding to occur
What is the theory and classification of species called?
Taxonomy
What is artificial classification?
. divides organisms according to differences that are useful at the time e.g. colour, size
. these are all analogous characteristics- similar features but not linked to evolution
What are the problems with artificial classification?
. some species occupying the same ecological niche can start to look very similar
. members of the same species can also begin to look dissimilar based on their environment
What is phylogenetic classification?
. putting organisms in groups based upon evolutionary relationships
. this method uses homologous characteristics- characteristics that have similar evolutionary origins, regardless of their functions e.g. wing of a bird, arm of a human
What are the three domains?
. bacteria- single celled prokaryotes
. archaea- single celled prokaryotes that are evolutionarily different to bacteria
. eukarya- a group of organisms made up of one or more eukaryotic cells
Describe bacteria:
. no membrane bound organelles
. no nucleus
. small 70s ribosomes
. circular DNA, no histones
. cell wall made of murein
. ester bonds between fatty acids and glycerol
Describe eukarya:
. membrane bound organelles
. nucleus
. large 80s ribosomes
. liner DNA, with histones
. if cell wall present, made of cellulose
. ester bonds between fatty acids and glycerol
Describe archaea:
. no membrane bound organelles
. no nucleus
. small 70s ribosomes
. circular DNA, no histones
. cell wall not made of cellulose or murein
. ester bonds between fatty acids and glycerol
. have a more complex form of RNA polymerase than the other domains
What are the four kingdoms?
. animalia
. plantae
. fungi
. protoctista
What comes after kingdom?
Phyla
What is the phylum that contains all animals who have spinal cords?
Chordata
What comes after phyla?
Class
What comes after class?
Order
What comes after order?
Families
What comes after families?
Genus
What comes after genus?
Species
What is a hierarchy?
Groups within groups with no overlap between each group.
What is the binomial naming system?
Organisms identified by two names:
. first=genus
. second=species
RULES
always underlined
first letter capitalized and second lower case
if species name is unknown written as sp
