4B - Classification of organisms Flashcards
What is phylogeny?
The study of the evolutionary history of organisms.
What have all organisms evolved from?
Shared common ancestors.
How can evolutionary relationships be shown?
On a phylogenetic tree.
What does phylogeny tell us?
Who is related to who and how closely related they are.
What is taxonomy?
The science of classification, it involves naming organisms and organising them into groups.
What are the 8 levels of taxonomy?
Domain Kingdom Phylum Class Order Family Genus Species
What is phylogenetic classification?
A system that attempts to arrange species into groups based on their evolutionary origins and relationships.
Can groups in the taxonomy system overlap?
No
How are groups arranged in taxonomy?
In a hierarchy with the largest groups at the top and the smallest groups at the bottom.
What is important to note about where organisms are found in the hierarchy in taxonomy?
Each organism can only belong to 1 group at each level in the hierarchy - there’s no overlap.
What are the 3 domains?
Eukarya, Bacteria and Archaea.
What is the definition of a species?
A group of similar organisms able to reproduce to give fertile offspring.
Why do scientists constantly update classification systems?
Because of discoveries about new species and new evidence about known organisms (e.g. DNA sequence data).
What naming system is used in classification?
The binomial naming system.
How many parts of a name are there is classification?
2
What are the 2 parts of the names used in classification?
The first part is the genus name and the second part is the species name.
What are the rules for writing names using the binomial naming system?
The first part is the genus name and it has a capital letter.
The second part is the species name and begins with a lowercase letter.
Names are always written in italics (or they’re underlined if they’re handwritten).
What does the binomial system help to avoid?
The confusion of using common names as there are lots of common names used for different things.
What is courtship behaviour used for?
To help classify species.
What is courtship behaviour?
Behaviour that helps attract a mate.
What is courtship behaviour essential for?
Survival of a species.
What is a taxon?
A group used to classify organisms.
What does courtship behaviour allow individuals to do?
Recognise members of their own species, Identify a mate that is capable of breeding. Form a pair bond. Synchronise mating. Become able to breed.
How does courtship help to prevent interbreeding?
Only members of the same species will do and respond to courtship behaviour allowing members of the same species to recognise each other.
What is courtship behaviour like with increasing closeness of relation?
The more closely related species are, the more similar their courtship behaviour.
What are some examples of courtship behaviour?
Fireflies give off pulses of light in a pattern specific to each species.
Crickets make sounds similar to Morse code, the code being different for different species.
Male peacocks show off their colourful tails - this tail pattern is only found in peacocks.
Male butterflies use chemicals to attract females - only those of the correct species respond.
How is courtship behaviour used in classification?
The courtship behaviour is specific to the species.
