02 Classification and Diversity of Life Free Online FlashCards

What does modern biological classification aim to reflect?

Modern classification aims to reflect common ancestry, not merely similarities among organisms.

How do taxonomy and systematics differ?

Taxonomy names and classifies organisms; systematics studies their diversity and evolutionary relationships.

What is the order of the familiar classification ranks?

Domain → kingdom → phylum → class → order → family → genus → species.

What rules govern a scientific name in binomial nomenclature?

A scientific name has a capitalized genus followed by a lowercase specific epithet; both are italicized, as in Homo sapiens.

What cellular feature distinguishes Eukarya from Bacteria and Archaea?

Bacteria and Archaea lack a nucleus; Eukarya have cells with a nucleus.

How are Archaea distinct from Bacteria despite both being prokaryotic?

Archaea and Bacteria both lack a nucleus, but they are genetically and biochemically distinct.

Why are “protists” not one single evolutionary branch?

“Protists” is an informal label for many mostly unicellular eukaryotes; they do not form one single evolutionary branch.

What does a branch point on a phylogenetic tree represent?

A branch point represents an inferred common ancestor. Taxa sharing a more recent branch point are more closely related.

Does rotating branches around a tree’s branch point change its relationships?

Rotating branches around a branch point does not change the evolutionary relationships shown.

How do homologous and analogous traits differ?

Homologous traits resemble each other because of shared ancestry; analogous traits evolved independently, often under similar environmental pressures.

What defines a clade?

A clade includes a common ancestor and all of its descendants.

What is the biological species concept, and one limitation?

It identifies species by the ability to interbreed and produce fertile offspring, but does not apply straightforwardly to fossils or asexual organisms.