Animal Taxonomy and Classification

This set of flashcards covers key concepts from the lecture on animal taxonomy and classification, focusing on major phyla and their distinguishing features.

What are the main characteristics of the Phylum Porifera?

Aquatic, amorphous body with choanocytes, ostia, osculum, archaeocytes, and spicules.

What distinguishes Eumetazoa from Parazoa?

Eumetazoa are true multicellular animals, while Parazoa includes simpler forms like sponges.

What are the defining features of Cnidaria?

Radially symmetrical, diploblastic animals with cnidocytes containing nematocysts, and polyp and medusa forms.

What is the dominant form of Scyphozoa?

Medusa, which reproduces sexually.

What defines the class Hydrozoa within Cnidaria?

Hydroids, mostly colonial organisms with a dominant polyp stage and tiny medusae for sexual reproduction.

What is a key characteristic of Anthozoa?

They exist only in the polyp form and include solitary sea anemones and colonial corals.

What distinguishes Lophotrochozoa from other protostomes?

They possess either a lophophore or a trochophore larval stage.

What type of body plan do Platyhelminthes exhibit?

Thin flat, elongated body with a ladder-type nervous system.

What are trematodes commonly known as?

Flukes, which are all parasitic with complex life cycles.

What is a distinguishing feature of molluscs?

A soft, three-part body plan consisting of the head-foot complex, visceral mass, and mantle.

What is the function of the radula in gastropods?

It acts as a feeding structure to scrape food.

What is unique about cephalopods compared to other molluscs?

They have closed circulation and exhibit complex behaviors, including jet propulsion.

What do nematodes lack that is present in other animal phyla?

Segments; they are non-segmented and taper at both ends.

What are the three main groups of arthropods?

Crustaceans, Chelicerates, and Uniramia.

What anatomical feature do echinoderms exhibit?

Secondary radial symmetry and a water-vascular system.

How are Chordates defined?

By the presence of a notochord, dorsal hollow nerve cord, pharyngeal gill slits, and a post-anal tail.

What two classes are part of the vertebrates and what are their differences?

Cyclostomata (e.g., hagfish, lampreys) lack jaws while Chondrichthyes (e.g., sharks) have moveable jaws.

How do amphibians breathe and reproduce?

They are tied to moisture for respiration and reproduction and undergo metamorphosis.

What adaptation do reptiles possess for reproduction?

The amniotic egg with a leathery or calcified shell.