BIOL 121 - Animal Taxonomy and Phylogeny

What are the classes in Phylum Porifera?

Demospongiae

Calcarea

Hexactinellida

How do Porifera reproduce?

Budding/Fragmentation; Hemaphroditic: sperm & egg

Porifera ____ contain true tissues

do not

Are Porifera motile?

No, they are mainly sessile as adults.

Are Porifera symmetrical or asymmetrical?

Asymmetrical.

Where do Porifera reside?

(Mainly) marine.

What is the synapomorphy for Porifera?

Choanocytes

What is a spongocoel?

The main body cavity of a sponge

What is an osculum?

The main opening of the sponge (at the top).

What is a pinacocyte

Epithelial-like cells that line the outermost body.

What is a mesohyl?

Thin layer of extracellular matrix that contain amoebocytes.

What is a spicule?

Structure that provides support to the sponge body.

Composed of silica or CaCO3.

Synapomorphy for Porifera

What is the function of choanocytes?

Responsible for filtering and engulfing food to digest them (via diffusion).

What is a lophocyte?

A cell that secretes collagen.

What is a porocyte?

A cell that controls water flow from the ostia.

What is a sclerocyte?

Cell that produces spicules.

What is a substratum?

Base, layer, or surface upon which an organism anchors to and grows.

How do Porifera eat and excrete nutrients?

Diffusion via pores.

What are amoebocytes?

Stem cells of the sponge that reside in the mesohyl.

What are feeding chambers?

Lined by choanocytes

Directs water through the sponge

How does digestion occur in a sponge?

Food is trapped and passed through the ostium and out the osculum.

What is segmentization?

Segments of a body that are linear and repetitive.

What is tagmatization?

Segments of an arthropod that are fused together to form a large unit

What are the exoskeletons of an Arthropod made of?

Chitin, proteins, and waxes (sometimes also CaCO3).

What is complete metamorphosis?

A four-stage insect life cycle where the larva differs in form, diet, and habitat from the adult stage.

Caterpillar to butterfly

Beetles

Flies

What is incomplete metamorphosis?

A three-stage life cycle where nymphs hatch into small, wingless adults that gradually develop wings through molting.

Grasshopper

What are compound eyes?

An eye with multiple openings, allowing insects to see a wide range of area.

What is chemoreception?

Pheromones that are detected by other animals that act like chemical messengers.

What is the synapomorphy for Nematoda?

Molting

Nematoda are ___ because male and females look different

dimorphic

What is a trochophore larva?

A free-living, water-habitual organism that resembles the shape of an egg.

What are radula?

Teeth-like structures that grab and push food into the mouth.

Mollusca have a ____ coelom

reduced

How do filter-feeders function?

Siphons are used to bring water into the organism.

What is metamerism segmentation?

Found in Annelids, where the body is separated into linear series of repeating muscles, nerves, and organs.

What symmetry do Echinoderms exhibit?

pentaradial