Lab Exam Review 4/25/2025

Phylum

A major taxonomic rank below Kingdom and above Class. A phylum is a principal taxonomic rank that subdivides kingdoms of organisms.

Class

A major taxonomic rank below Phylum and above Order. A class is a principal taxonomic rank that subdivides phyla of organisms.

Phylogenetic Tree

A branching diagram or 'tree' showing the inferred evolutionary relationships among various biological species or other entities—their phylogeny—based upon similarities and differences in their physical or genetic characteristics.

Body Cavity

Any space or compartment, or potential space in the animal body. It may contain organs or be lined by a membrane.

Tissue

A group of similar cells and their intercellular substance which function together to perform a specific activity.

Epithelial Tissue

Tissue that covers the surfaces of the body, inside and out. It forms the covering of all internal and external surfaces, lining of body cavities and hollow organs, and is the major tissue in glands.

Nervous Tissue

The main tissue component of the nervous system, involved in sensing stimuli and transmitting information.

Muscle Tissue

Tissue that allows for movement. There are three types: skeletal, smooth, and cardiac.

Bone Tissue

A type of connective tissue that forms the rigid structure of the skeleton.

Osteocyte

A bone cell, formed when an osteoblast becomes embedded in the matrix it has secreted.

Neuron

A specialized cell transmitting nerve impulses; a nerve cell.

Anterior

Towards the front of the body.

Posterior

Towards the back of the body.

Dorsal

Towards the back or upper side of an organism.

Ventral

Towards the front or lower side of an organism.

Cross-section

A cut or slice made horizontally across an organism or structure.

Development

The process by which an organism grows and changes over its life cycle.

Life Cycle

The series of changes that an organism undergoes from the beginning of its life to the time it reproduces.

Protozoan

A single-celled eukaryotic organism, typically motile.

Deuterostome

Animals in which the blastopore becomes the anus during development, and the mouth is formed secondarily.

Polychete

A class of annelid worms, mostly marine, with parapodia bearing many bristles (setae).

Gastropod

A large class of mollusks that includes snails and slugs.

Tunicate

Marine invertebrate animals, constituting the subphylum Tunicata of the phylum Chordata.

Planarian

A free-living flatworm of the class Turbellaria.

Lancelet

Small, fish-like marine chordates that lack a true backbone.