CH 18 Flashcards
What is the goal of systematics?
To organize living things into group[s that have biological meaning
The polar bear belongs to the genus Ursus and the species maritiumus. How would you write its Linnaean name?
Ursus maritimus
What is taxonomy?
the science of the classification of living things.
Describe Linnaeus’ system of hierarchical taxonomy. List the ranks from smallest to largest.
Linnaeus’ original classification ssystem had four levels. over time it expanded to include seven hierarchical taxa: Species, genus, family, order, class, phylum, and kingdom.
What is the largest and most inclusive of Linnaeus’ taxonomic categories? What is the smallest and most restrictive?
The Kingdom; species and genus
What are some of the problems with Linnaean classification?
Linnaeus grouped organisms strictly according to similarities and differences. Scientists today try to assign species to a larger group in that reflect how closely members of those groups are related to each other.
What is phylogeny? What is the goal of evolutionary classification?
The evolutionary history of lineages; To group species into larger categories that reflect lines of evolutionary descent
Define clade.
Group of species that includes a single common ancestor and all descendants of that ancestor
Explain the difference between a monophyletic and paraphyletic group.
Monophyletic groups include a single common ancestor and all its descendants, while paraphyletic groups include a common ancestor but excludes one or more groups of descendants.
Explain how cladograms are built.
A cladogram is built by linking groups of organisms by showing how evolutionary lines, or lineages, branched off from common ancestors.
What is a derived character?
A trait that arose in the most recent common ancestor of a particular lineage that was passed on to its descendants
How do taxonomists use DNA to determine how closely two species are related?
By comparing the genetic information between two species
List the six kingdoms of life.
Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia.
Describe the Eubacteria kingdom
Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia. Eubacteria are prokaryotes, cell walls have peptidoglycan, are unicellular, autotroph or heterotrophs. Streptococcus, Escherichia coli
Describe the Archaebacteria kingdom
Archaebacteria are prokaryotes, cell walls do not contain peptidoglycan, are unicellular, autotrophs or heterotrophs., Methanogens, halophiles
Describe the “Protista” Kingdom
“Protista” are eukaryotes, cell walls contain either cellulose or chloroplasts. Most unicellular, some colonial, some multicellular, autotroph or Heterotroph, Amoeba, slime mold
Describe the Fungi Kingdom
Fungi are Eukaryotes, cell walls contain chitin, most multicellular, some unicellular, are heterotrophs. Mushrooms, yeasts
Describe the Plantae Kingdom
Plantae are Eukaryotes, cell walls contain cellulose or chloroplasts, most are unicellular, some green algae unicellular, are autotrophs. moss, ferns
Describe the Animalia Kingdom
Animalia are Eukaryotes, no cell walls or chloroplasts, are multicellular and heterotrophic. Sponge, worm
List the three domains of life
Domain Archaea, Eukaryea, and bacteria.
Describe the Bacteria Domain
Unicellular, prokaryotic with thic cell walls containing peptidoglycan. Ecologically diverse, some need oxygen, some are killed by oxygen. Corresponds to Kingdom Eubacteria
Describe the Archaea Domain
Unicellular and prokaryotix, live in most extreme environments such as volcanic hot springs, brine pools, and black organic mud devoid of oxygen. Most can only survive in lack of oxygen. Lack peptidoglycan, cell membranes contain lipids. Corresponds to kingdom Archaeabacteria
Describe the Eukarya domain
consists of all organisms that have a nucleus. Most are unicellular but some are multicellular. Some are photosynthetic while others heterotrophic.
All three domains represent clades, but only five of the six kingdoms are clades. Which kingdom is not a true clade and why?
Kingdom Protista does not form any monophyletic group. The unicellular eukaryotes in this group are not counted as animals, plants, or fungi. They do not have any common ancestors.
