Week 1 Flashcards
tree of life
A family tree of organisms.
phylogeny
Organisms’ actual genealogical relationships.
phylogenetic tree
A diagram that depicts evolutionary history according to their phylogeny.
eukaryotes
Have a prominent component called the nucleus.
Multicellular.
prokaryotes
Lacks a nucleus. (Bacterial and Archaeal cells)
Unicellular.
taxonomy
The effort to name and clarify organisms.
taxon (plural: taxa)
Any named group based on its phylogeny.
domain
The highest taxonomic category, consisting one or more kingdoms. Living organisms are divided into three domains: Archaea, Eubacteria, Eukarya.
phylum (plural: phyla)
Major lineages within each domain. Arbitrary designation but considered a major branch on the tree of life.
genus (plural: genera)
Made up of a closely related group of species. (e.g. Homo genus, consisting of humans and other extinct species)
species
Organism’s species, always preceded by its genus. (e.g. sapiens for humans)
scientific name
Naming system consisting of two parts: genus and species. Genus always precedes species identification and is always capitalized, and both italicized.
No identical genus and species names should exist.
LUCA
Last Universal Common Ancestor
molecules
Substances held together by covalent bonds.
compounds
Atoms of different elements that forms a bond.
electronegativity
Properties of an element in a compound where they may pull shared electrons towards their nuclei with varying strength.
nonpolar covalent bond
A bond that involves equally shared electrons.
polar covalent bond
Asymmetric sharing of electrons. Electrons in this bond spends most of their time close to the nucleus of the more electronegatitve atom.
ionic bonds
Bonds involving a complete transfer of electrons from one atom to other resulting in a full valence shell.
ion
An atom or molecule that carries a full charge.
cation
Positively charged ions.
anion
Negatively charged ions.
