6.01 The Classification of Living Organisms Flashcards
Aristotle a scientist …
created the classification system for living things.
Aristotle…
created “The Great Chain of Being.” Putting Humans on the top.
Carolus Linnaeus…
a Swedish botanist , created a new classification system that sorted organisms by their physical traits, not their complexity. A modern version of this classification method, Linnaean taxonomy , is used today.
the five kingdoms are …
Animals, Plants, Fungus, Protists, and Bacteria.
Binomial nomenclature…
gives a two-word name to organisms based on the Latin language, such as the use of Felis catus to to describe a common house cat.
1970s, a scientist named Carl Woese…
use nucleic acid sequences and ribosomal RNA to determine links between organisms. These links revealed that organisms with similar physical characteristics were not necessarily related to one another. In the case of the Bacteria kingdom, ribosomal RNA uncovered the existence of two separate groups of bacteria, Eubacteria and Archaeabacteria . Although they looked similar on the outside, these two bacteria groups were very similar.
Phylogeny…
Cladistics…
is the evolutionary history of a group of genetically related species. This evolution of species is represented by a phylogenetic tree of ancestors and descendants , linking one species to another in a chain starting from the bottom of the tree to the top. Each new branch of the tree represents a change in the line of shared traits.
depicts hypotheses about how organisms are related based on the traits of their ancestors and descendants. It uses a chart called a cladogram that is similar in concept to the phylogenetic tree but more concise in design. Cladograms use clades, a group of organisms that include an ancestor species and all its descendants. Relationships between ancestors are shown on a binary tree, where every fork has exactly two branches, each clade represented by a fork. Relationships are determined by ancestral traits inherited from a common ancestor. When a new trait develops, called a derived trait, a fork is added to a cladogram.
viral infections: lytic and lysogenic…
In a lytic infection, the virus enters the host cell, replicates many copies, and destroys the cell in order to get out and spread to others. In a lysogenic infection, the virus incorporates its DNA into the DNA of the cell. It stays dormant and replicates with the cell DNA until the cell is in danger of dying. At that time, the lysogenic infection will become lytic in order to spread to other host cells.
Eubacteria:
includes prokaryotic organisms.
Archaebacteria:
complex structures, and many other organisms
