Ch. 18

Flashcards to review key concepts about invertebrate animals.

Invertebrates are animals that lack __.

A backbone.

The phylum Porifera includes __.

Sponges.

Cnidarians, such as jellies and corals, have a __ body plan.

Diploblastic, radial.

The two body plans of Cnidarians are and .

Polyp; medusa.

Ecdysozoans are defined by a process called __.

Ecdysis.

Arthropods possess a hard external skeleton called __.

Chitin.

The class of Arthropoda that includes spiders and scorpions is called __.

Cheliceriformes.

Aquatic arthropods typically breathe through or systems.

Gills; tracheal.

Molluscs have a body plan that typically consists of three main parts: muscular foot, visceral mass, and __.

Mantle.

The term metamorphosis refers to the __ change in an organism's life cycle.

Developmental.

Sponges reproduce both and .

Sexually; asexually.

Nematodes, or roundworms, are known for having a tough __ that is periodically shed.

Cuticle.

Annelids are characterized by their __ body structure.

Segmented.

The phylum Arthropoda includes insects, arachnids, and __.

Crustaceans.

Echinoderms possess a unique __ system used in locomotion and feeding.

Water vascular.

The process of shedding an exoskeleton is known as __.

Ecdysis.

Molluscs include octopuses, squids, and __.

Snails.

Class Bivalvia includes animals like clams and __.

Oysters.

The class of Cnidaria that includes corals and sea anemones is known as __.

Anthozoa.

What are invertebrates?

Animals that lack a backbone.

Which phylum includes sponges?

Phylum Porifera.

What body plan do Cnidarians have?

Diploblastic, radial body plan.

What are the two body plans of Cnidarians?

Polyp and medusa.

What process is defined by Ecdysozoans?

Ecdysis.

What is the hard external skeleton of arthropods called?

Chitin.

What class of Arthropoda includes spiders and scorpions?

Cheliceriformes.

How do aquatic arthropods typically breathe?

Through gills or tracheal systems.

What three main parts make up the body plan of molluscs?

Muscular foot, visceral mass, and mantle.

What does the term metamorphosis refer to?

The developmental change in an organism's life cycle.

How do sponges reproduce?

Both sexually and asexually.

What is the tough layer that nematodes shed called?

Cuticle.

What characterizes the body structure of annelids?

Segmented body structure.

What does the phylum Arthropoda include?

Insects, arachnids, and crustaceans.

What system do echinoderms use for locomotion and feeding?

Water vascular system.

What is the process of shedding an exoskeleton called?

Ecdysis.

What types of creatures do molluscs include?

Octopuses, squids, and snails.

What does Class Bivalvia include?

Animals like clams and oysters.

What class of Cnidaria includes corals and sea anemones?

Anthozoa.