Species, Taxonomy Flashcards
Organisms of the same species can…
Breed to produce fertile living offspring
Binomial naming system
First name = denotes genus (eg. Vibrio)
Second name = denotes species (eg. fischeri)
How would you name something if you know the genus but not the species? Eg. Vibrio …
Vibrio sp.
Why is it important that mating is successful and offspring have a maximum chance of survival?
Often females only produce eggs at specific times even only once a year so need to make sure this mating is successful and offspring survive
What does courtship behaviour enable individuals to do? (5)
Recognise members of their own species - to endure mating take spaces between mementos of the same species so they can produce living fertile offspring
Identify a mate that is capable of breeding - because both species need to be sexually mature, fertile and receptive to mating
Form a pair bond - that will lead to successful mating and raising of offspring
Synchronise mating - so that it takes place when there is maximum probability of the sperm and egg meeting
Become able to breed - by bringing a member of the opposite sex into a physiological state that allows breeding to occur
Talk about males determining the receptive stage of females
Females undergo cycle of sexual activity where they can only conceive for a short period of time. They are often only receptive to mating in this period so courtship behaviour is used by males to determine whether females are in this receptive stage.
Responding with appropriate behavioural response = courtoisie continues and offspring occur
If not makes focus on another female
Talk about the special signals and communications between potential mates
Courtship animals use signals and behaviour to communicate with a potential mate.
This allows both individuals to recognise their partner is of the same species and so they are prepared to mate. Typically there is a chain of actions between the male and female. This chain of actions will stay the same for all members of a species but différent species have different chains of action etc.
Define classification
The grouping of organisms
Define taxonomy (and what it involves)
The theory and practice of biological classification of life which involves naming organisms and sorting them into groups (that do not overlap)
Two main forms of biological classification?
Artificial
Phylogenetic
Artificial classification
Groups organisms according to observed features. IRRESPECTIVE OF EVOLUTIONARY ORGANISMS.
Eg. Size, colour, number of legs
Analogous characteristics
Same function or appearance but different evolutionary origin
(Eg. Bat, bird and insect wing)
Phylogenetic (natural) classification
definition + (three things)
Phylogenetic classification is a system that attempts to arrange species into groups based on their evolutionary origins and relationships.
- based upon the evolutionary relationships between organisms and their ancestors
- classifies species into groups using shared features derived from their ancestors
- arranges groups into a hierarchy where there are groups within groups but no overlap
Homologous characteristics
Characteristics which have similar evolutionary origins regardless of their function
(Eg. Sing of bird, arm of human, leg of horse all have same evolutionary origin)
Three main domains
Bacteria
Archaea
Eukarya
Bacteria characteristics
- single celled prokaryote
- NO membrane bound organelles
- unicellular
- 70S ribosomes
- cell walls present and made of murein (never chitin or cellulose)
- circular DNA NO HISTONES
Archea characteristics
- single celled prokaryotes
They differ from bacteria because:
- genes and protein synthesis more similar to eukaryotes
- membranes contain fatty acid chains attached to glycerol by ether linkages
- no murein in their cell walls
- have a more complex form of RNA polymerase
What were archaea originally classified as?
Bacteria due to similar appearance
Eukarya characteristics
Organisms made up of one or more eukaryotic cells
- YES membrane bound organelles
- have membranes containing fatty acid chains linked to glycerol by ESTER linkages
- not all have cell walls (when they do it is made of murein)
- ribosomes 80S
What domain are the 4 kingdoms part of?
Eukarya
Name the 4 kingdoms of eukarya
Protoctista
Fungi
Plantae
Animalia
State the 7 taxonomic ranks
Kingdom Phylum Class Order Family Genus Species
Define Phylogeny
Study of evolutionary relationships and origins between organisms
(Who’s related to who and how closely are they related)
PHYLOGENY IS TAKEN INTO ACCOUNT WHEN SORTING INTO GROUPS AND CLASSIFYING ORGANISMS
Phylogenetic trees represent …
Phylogenetic relationships of different species
First branch point of a phylogenetic tree is the
Common ancestor (now extinct)
How to tell closely related species in a phylogenetic tree
They have diverged away from each other more recently (don’t have to look as far back to see branching point)
When sorting organisms into groups, scientist take…
Phylogeny into account and group organisms according to their evolutionary relationships
How many levels of groups are used to classify organisms ?
What are all these groups called together and what are they called separately?
8
Taxa
Taxon
What makes the taxa a hierarchy?
The largest group is at the top (domain)
And the smallest is at the bottom (species)
What do we mean when we say there is no overlap of organisms in the taxa?
Organisms can only belong to one group at each level in a hierarchy
XXXX
What happens as you move down the hierarchy (8 taxons)?
More groups at each level (what does this actually mean???) - more orders at each level ???
But less organisms in each group Although the organisms in each group are more CLOSELY RELATED
Define species
A group of similar organisms that are able to reproduce to give fertile offspring
What naming system is used in classification?
The binomial naming system
How can courtship behaviour be used to classify organisms?
Closely related species have more similar courtship behaviour
How could you deceive courtship behaviour?
Species specific
Only members of the same species will do and respond to courtship behaviour. This allows members of the same species to recognise each other so that reproduction can be more successful and fertile offspring can be produced.
3 example of courtship behaviour
Male peacocks showing off colourful tails
Fireflies give off pulses of light
Butterflies release chemicals