Invertebrate Animal Groups Review

These flashcards help review key concepts related to invertebrate animal groups, including classifications, anatomical features, and developmental characteristics.

What does the term 'coelum' refer to in animal classification?

Coelum refers to the body cavity.

What group of animals is characterized by having no body cavity and is classified as a basal group?

Phylum Acoela.

Do the members of the group Acoela have a true mouth?

No, they do not have a true mouth.

What is a key characteristic of protostomes?

The blastopore becomes the mouth.

Which type of cleavage do protostomes exhibit?

Spiral cleavage.

What are the two main groups of protostomia?

Lophotrochozoa and Ecdysozoa.

What does 'Lophotrochozoa' refer to?

It refers to a group of protostomes that have either a lophophore feeding apparatus or a trochophore larval form.

What are platyhelminthes commonly known as?

Flatworms.

What type of gut structure do flatworms have?

They have an incomplete gut, meaning they have a gastrovascular cavity.

What is cephalization?

Cephalization is the clustering of neurons at one end of the body, often forming a head region.

Name one example of a parasitic flatworm.

Flukes or tapeworms.

What does the phylum Mollusca include?

Organisms with soft bodies, often with shells; examples include snails and clams.

What does 'a eucoelomate' mean?

An organism with a true coelom that arises from the mesoderm.

Which mollusks lack a radula?

Bivalves.

What does what 'annelid' mean?

Small rings, referring to the segmented bodies of this group.

What is a defining characteristic of nematodes?

They are pseudocoelomates.

What does the term 'arthropoda' refer to?

Animals with jointed feet.

What is a key characteristic of the phylum Arthropoda?

They possess a well-defined exoskeleton made of chitin.

What are the four main subphyla of Arthropoda?

Chelicerata, Myriapoda, Crustacea, and Hexapoda.

What does 'deuterostome' mean?

The blastopore becomes the anus during development.

What is a key feature of echinoderms?

They exhibit pentaradial symmetry as adults.

What is the significance of cephalization in animals?

It allows for the organization of sensory organs and nervous systems towards one end, facilitating more complex behaviors.

What is the most diverse group of arthropods?

Insects (Hexapoda).