Classification Flashcards
What is classification
The arrangement of organisms into groups of various sizes on the basis of shared features
What is taxonomy
Form of classification that focuses on physical similarities between different species
What is phylogeny
Classification of organisms by their evolutionary relationships so every group shares a common ancestor
Three reasons for classification
-to identify species using clearly defined systems
-predict characteristics-if others in group have specific characteristics likely others in same group will have same
-find evolutionary links-evolved from common ancestors
What is binomial name
Genus (upper case) + species(lower case)
-if subspecies identified an extra name is added to name at end in lower case
Who introduced first formal system of taxonomy
Linnaeus
Linnaean classification system
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is phylogenies species concept
Defines a species by its evolutionary lineage, where two lines diverge sufficiently they are called separate species (hard to decide if sufficiently diverged)
Problems with defining species as interbreed to give fertile offspring
Geographical separation, only applies to organisms that reproduce sexually, if species extinct/ sterile
What are the five kingdoms in Linnaean system
Plantae, Animalia, Fungi, Protista and Prokaryotae
What is an autotroph
Organisms able to manufacture its own sugars from simple molecules by photosynthesis eg plants
What is a heterotroph
Organism dependent on other organisms for food eg animals
What does saprophytic mean
Organism that eats dead matter
Describe plantae kingdom
-autotrophs, cellulose cell wall, have nucleus and microtubules, eg trees and mosses
Describe animalia kingdom
-multicellular heterotrophs, have nervous and muscular systems so can react quickly to environmental stimuli, mobile so can move spontaneously and voluntarily
Describe fungi kingdom
-eukaryotic heterotrophic(specifically saprophytic) organisms with chitin cell wall, reproduce via spores, vegetative parts consist of myecilium which extend underground, have nucleus and microtubules
Describe Protista kingdom
Eukaryotic with little in common, protophyta resemble plants and Protozoa resemble animals , generally unicellular with some cells walls, eg algae and plasmodium
Describe prokaryotae kingdom
Bacteria and other unicellular organisms with genetic material loose in cell, subdivided into eubacteria and archaebacteria based on molecular phylogenies , peptidoglycan cell wall
Three domain system
-eubacteria, archaebacteria and eukaryota
-based on RNA (molecular systematics)
What do archaea share
Similar enzymes for building RNA, mechanisms for DNA replication and production of proteins that bind to DNA
How to read phylogenetic trees
Tips represent groups of descendant organisms while nodes represent common ancestors
What are non-coding DNA called and why are they useful
Introns, very good indicator of relatedness as not due to evolutionary pressure so indicative of common ancestors between species
What is molecular systematics
Looking at DNA/proteins and identifying differences and similarities, more similarities the more closely related so more recent common ancestor
