W25 - BioSci 94 - L.11 (Protostomes)

Multicellular

Organisms composed of multiple cells, which is a common characteristic of animals.

Heterotrophic

An organism that cannot synthesize its own food and is dependent on complex organic substances for nutrition.

Protostome

A major group of animals where the blastopore develops into the mouth during early embryonic development.

Deuterostome

A major group of animals where the blastopore develops into the anus during early embryonic development.

Gastrulation

The process during embryonic development that leads to the formation of the germ layers.

Ecological role

The part that an organism plays in its ecosystem, including its interactions with both biotic and abiotic factors.

Millipedes

Terrestrial arthropods characterized by having two pairs of legs per body segment.

Centipedes

Terrestrial arthropods characterized by having one pair of legs per body segment.

Ecdysis

The process of shedding the old exoskeleton to allow for growth in certain invertebrates.

Chelicerae

Claw-like mouthparts found in chelicerates, used for feeding.

Mantle

The tissue layer that covers the visceral mass in mollusks and secretes the shell.

Trochophore

A free-swimming larval stage typical of certain animal groups including many mollusks and annelids.

Lophophore

A feeding structure with ciliated tentacles found in some lophotrochozoans.

Incomplete metamorphosis

A type of insect development where the juvenile form resembles a small adult and does not undergo a distinct larval stage.

Complete metamorphosis

A type of insect development that includes a distinct larval stage, pupa stage, and an adult stage.

Anticoagulant

A substance that prevents blood coagulation, as produced by leeches.

Bilateral symmetry

A body plan in which the left and right sides of the organism are mirror images.

Chitin

A long-chain polymer that is a primary component of the exoskeleton in arthropods.

Ecdysozoa

Superphylum of animals that grow by molting, including arthropods and nematodes.

Water bear

Common name for Tardigrada, small water-dwelling organisms known for their resilience.

Bioindicator

An organism used to assess the health of an environment or ecosystem, typically due to its sensitivity to environmental changes.