Lecture on Bilateria and Platyhelminthes

This set of flashcards contains key vocabulary terms and definitions related to the study of Bilateria and the Phylum Platyhelminthes, helping students familiarize themselves with critical concepts for their exam.

Bilateria

A clade that includes organisms with bilateral symmetry, having a left and right side that mirror each other.

Acoelomate

An organism lacking a coelom, or body cavity, typically found in flatworms.

Phylum Platyhelminthes

A phylum of flatworms characterized by bilateral symmetry and a flattened body.

Cestoda

A class within Platyhelminthes consisting of endoparasitic tapeworms.

Trematoda

A class within Platyhelminthes that includes flukes, which are parasitic and often have complex life cycles.

Monogenea

A class of flatworms that are ectoparasites often found on fish.

Neodermata

A superclass that includes parasitic flatworms with a specialized outer layer.

Scolex

The anterior part of a tapeworm, equipped with hooks or suckers for attachment.

Proglottid

A segment of a tapeworm containing both male and female reproductive organs.

Miracidium

The free-swimming larval stage of trematodes that hatch from eggs and seek a suitable intermediate host.

Cercaria

The larval stage of trematodes that emerges from the intermediate host and can penetrate the definitive host.

Metacercaria

The encysted larval stage of trematodes that develops in the definitive host, often in muscle or tissues.

Flame cells

Specialized cells in flatworms involved in excretion and osmoregulation.

Rhynchocoel

A body cavity in nemerteans that houses the proboscis.

Trochophore larvae

A type of larval stage that is common in marine invertebrates, including some groups of flatworms.

Neoblasts

Stem cells in flatworms that facilitate regeneration and development.