Classification and Phylogeny of Animals and Animal-like Protists

These flashcards cover key vocabulary terms related to the classification and phylogeny of animals and the characteristics of animal-like protists.

Classification

The systematic arrangement of animals into groups based on shared characteristics.

Phylogeny

The evolutionary history and relationships among animal groups, often represented as a phylogenetic tree.

Phylogenetic Tree

A branching diagram that represents the evolutionary relationships among various species.

Homology

Character similarity that results from common ancestry.

Convergent Evolution

Different lineages developing similar features independently.

Monophyletic Taxon

A taxon that includes the most recent common ancestor and all descendants of that ancestor.

Paraphyletic Taxon

A taxon that includes the most recent common ancestor of all members of a group but not all descendants.

Polyphyletic Taxon

A taxon that does not include the most recent common ancestor of its members.

Binary Fission

An asexual reproduction process where one individual splits into two equal-sized individuals.

Zooflagellates

Protozoans that move using flagella and can be free-living or parasitic.

Amoebas

Protozoans that move and feed by forming pseudopods.

Ciliates

Protozoans that use hair-like projections called cilia for movement and feeding.

Apicomplexans

Parasitic protists that have complex life cycles and no means of locomotion.

Cysts

Dormant forms of protists with resistant outer coverings that can survive harsh conditions.

Eyespot

A localized region of pigment in some protists that can detect changes in light.

Sarcodina

A group of protozoans that use pseudopods for feeding and movement.

Taxonomic Group

A category used to classify organisms in taxonomy based on shared characteristics.

Cladistics

A method of classification based on common ancestry and the branching of lineages.

Contractile Vacuoles

Cellular structures in freshwater protozoans that help expel excess water.

Trophozoite

The active, feeding stage of protozoans, as opposed to the cyst stage.