Invertebrate Phyla Overview

A collection of flashcards covering key concepts regarding the phyla Porifera, Cnidaria, Ctenophora, Platyhelminthes, Rotifera, and Annelida.

What are Porifera commonly known as?

Sponges.

What level of organization do sponges have?

Cellular level of organization.

What are ostia in sponges?

Small pores through which water enters.

What are oscula in sponges?

Large openings through which water exits.

What are spicules made of?

Calcium carbonate or silica.

What is spongin?

A flexible protein that provides structural support in some sponges.

What function do choanocytes serve in sponges?

They create water currents for filter feeding.

What are archaeocytes?

Amoeba-like cells with various functions in sponges.

What is mesohyl?

A gelatinous matrix within a sponge.

What is the spongocoel?

The central cavity of a sponge.

How do sponges feed?

They are sessile filter feeders.

What does it mean for sponges to be hermaphrodites?

They produce both eggs and sperm.

What is a gemmule?

An internal bud formed by sponges for survival during unfavorable conditions.

What are the three body forms of sponges?

Asconoid, Syconoid, Leuconoid.

What is radial symmetry?

A body plan organized around a central axis, typical of Cnidarians.

What do Cnidarians lack in their tissue organization?

Complex organs.

What is polymorphism in Cnidarians?

The existence of two different body forms: Polyp and Medusa.

What is a scyphistoma?

The polyp stage of a jellyfish.

What are cnidocytes?

Specialized stinging cells containing nematocysts.

What is the function of nematocysts?

They inject toxins into prey or provide defense.

What does the nerve net in Cnidarians do?

Allows them to respond to stimuli.

What characterizes a planula larva?

It is a free-swimming, ciliated larva of Cnidarians.

What are zooxanthellae?

Symbiotic dinoflagellates in corals providing nutrients through photosynthesis.

What does ocean acidification affect?

It harms corals and marine organisms with calcium carbonate structures.

What are ctenes in Ctenophora?

Fused, ciliated plates used for locomotion.

What is unique about Ctenophora regarding their gut?

They possess the first complete gut.

What does the term 'triploblastic' mean?

Having three germ layers.

What is the function of flame cells in flatworms?

They function in osmoregulation.

What is a scolex in tapeworms?

The head equipped with hooks and suckers for attachment.

What are the main reproductive strategies of Rotifera?

Parthenogenesis and sexual reproduction under stress.

What is characteristic of segmented worms (Annelida)?

Their body is divided into repeating segments.

What do parapodia do in polychaetes?

They assist in locomotion.

What is a clitellum in earthworms?

A thickened band that secretes mucus for cocoon formation.

What is one role of nephridia in annelids?

They filter waste from the coelomic fluid.