Chapter 12 Flashcards
Systematics
The scientific study of this biological diversity and it’s evolutionary history
Goal is to discover all the branches of phylogenic tree of life, depicting the genealogical relationship of organisms
Taxonomy
Identifying naming and classifying species
Began with Carl Linnaeus
Polynomial- proper name for species
Permanent binomial system of nomenclature
Type specimen
A dried plant specimen housed in a museum or herbarium by the person who named it
Serves as a basis for comparison with other specimens
3 kingdoms
Plant, animal, and monera
Taxonomic categories
Generra grouped into families, families into orders, and orders into classes
Augustin Pyramus de Candolle, invented the word taxonomy
Taxon: the group at any level
Category: the level at which it is ranked
Linnaeus “sexually system”
Artificial systems
Plants classified into 24 classes based on the number and arrangement of stamens in each flowers
Monophyletic group (Clade)
Composed of an ancestor and all its descendants
Can be removed by one cut
Genus
Consist of all species descended from the most recent common ancestor
Family
All genera Descended from a more distant common ancestor
Paraphyletic group
One consisting of a common ancestor, but not all descendants of that ancestor
Polyphyletic group
set of organisms, or other evolving elements, that have been grouped together but do not share an immediate common ancestor
Homologous
Common origin but not necessarily a common function
Analogous
Structures that may have a similar function and superficial appearance, have an entirely different evolutionary background
Are the result of convergent evolution
Synamorphies
Character states that arose in the common ancestor of the group and are present in all of its members
Character states: two or more forms of a particular feature (present +) (absent -)
Outgroup
the set of organisms under study, serves as a reference group when determining the evolutionary relationships of the ingroup
Cladogram
Provides a graphical representation of a working model or hypothesis of phylogenic relationships among a group of organisms
Principle of parsimony: evolutionary pathways should be constructed in the simplest least complicated and most efficient way
Inverted repeats
Two regions of the chloroplast genome that encode the same genes but in opposite directions; between them or a single copy region and a large single copy region.
Supergroup
Lies between a domain and a kingdom
Serial endosymbiotic theory
Mitochondria and chloroplasts are believed to be the descendants of bacteria that were taken up and adopted by an ancient cell
Mitochondria appeared before chloroplasts
Endosymbiont
An organism that lives within another, dissimilar organism
3 types of endosymbiosis
Primary- Cyanobacteria are ingested by eukaryotic host, evolve into plastids each is bounded by an envelope of two membranes (2 membranes)
Secondary: eukaryotic cells w/ plastids are engulfed by another eukaryotic cell and evolve into secondary plastids (3 or 4 membranes)
Tertiary: the eukaryotic cells have a plastics derived from a eukaryotic endosymbiont with a secondary plastid, (2+ membranes)
Gametophyte
Plants haploid gamete
Sporophyte
Diploid spore producing in plants (Algae)
Isomorphic
When the haploid and diploid forms are the same in external appearance.
Gametophyte facts (3)
Female gametophytes consist of 7 cells, males 3
Both are nutritionally dependent on the sporophyte.
