Classification of organisms. Flashcards
What is the branch of biology that names and groups organisms according to their characteristics and evolutionary history?
Taxonomy.
Who was the first person to classify organisms?
Aristotle.
What was the first classification of animals?
Land dwellers.
Water dwellers.
Air dwellers.
How were plants first categorised?
Plant were put into categories based on their stem.
Why did the early system of classification become inadequate?
Categories were not specific enough.
Common names did not describe a species accurately.
Names were long and hard to remember.
Historically what has been used to classify organisms?
Historically the most important and distinguishing characteristics have been anatomical.
What do scientists use for organism classification today?
Today, scientists are also considering molecular level differences such as nucleotide sequences of DNA and the structure of chromosomes.
Who laid the groundwork for the modern classification system?
Carl Linnaeus.
How does the Linnaeus system of classification work?
It places an organism into a series of hierarchically arranged categories on the basis of its resemblance to other organisms.
He also introduced the scientific name.
What are the components of a scientific name?
A species scientific name consists of a genus—the generic name—and the species (written in italics with genus capitalized and species lowercase)
What are the three domains of classification of organisms?
Bacteria.
Archaea.
Eukarya.
Of the 3 domains which ones descended from prokaryotes?
Bacteria.
Archaea.
What are the seven categories or taxa in the Linnaean classification system?
Kingdom.
Phylum.
Class.
Order.
Family.
Genus.
Species.
What can happen to reproductively isolated populations within a species?
Individuals of which could interbreed if isolation/barriers were removed.
Occupy distinctly separate geographic ranges.
Frequencies of specific genes/alleles can be significantly different between reproductively isolated populations.
What is the food chain?
Energy stored by plants that moves through the ecosystem in a series of steps of eating and being eaten.
Are food chains linear?
No.
What are trophic levels?
The grouping of species into categories based on common source of food.
What is the 1st trophic level?
Primary producers
Plants! (phytoplankton in marine ecosystem).
What is the 2nd trophic level?
Primary consumers
Herbivores (essential for higher trophic levels!).
What is the 3rd trophic level?
Secondary consumers
Carnivores (first level carnivores).
What is the 4th trophic level?
Tertiary consumers
Carnivores (second level carnivores).
What is the 5th trophic level?
Quaternary consumers
Carnivores (third level carnivores).
What is the 6th trophic level?
Decomposers
Feed on detritus
All consumers are decomposers in some way (i.e. feces)
Critically important!
Bacteria (other microbes) primary decomposers in the ocean.
What is an ecological pyramid?
Indicates the amount of energy flow at each trophic level.
