bio lab 9: animal diversity I

What is symmetry in animals?

The arrangement of body parts (asymmetrical, radial, bilateral).

What is cephalization?

Concentration of sensory structures and brain at the anterior (head) end.

What are the three tissue layers?

Ectoderm, mesoderm, endoderm.

What is the difference between diploblastic and triploblastic animals?

Diploblastic: 2 layers (ectoderm + endoderm)

Triploblastic: 3 layers (adds mesoderm)

What are the three body cavity types?

• Acoelomate (no cavity)

• Pseudocoelomate (partial cavity)

• Coelomate (true cavity)

What are the types of digestive systems?

• Incomplete (one opening)

• Complete (mouth and anus)

What is segmentation?

Body divided into repeating units.

How do you identify a sponge?

Asymmetrical, porous body, no true tissues.

What is the osculum?

Large opening where water exits.

What is the spongocoel?

Central cavity inside the sponge.

What are choanocytes?

Flagellated cells that move water and trap food.

What phylum does Hydra belong to?

Cnidaria

Is Hydra a medusa or polyp?

Polyp

What are cnidocytes?

Stinging cells used for defense and capturing prey.

Function of cnidocytes?

Inject toxins into prey

What is the gastrovascular cavity?

Central cavity for digestion and distribution

What are the layers in Hydra?

Epidermis, gastrodermis, mesoglea

What is the basal disc?

Structure used for attachment.

Where is the mouth/anus in Hydra/cnidaria

?

Same opening at the top. (Hydra/cnidaria)

What phylum does Planaria belong to?

Platyhelminthes

What type of symmetry do planarians have?

Bilateral symmetry

What are eyespots?

Light-detecting structures.

What are auricles?

Sensory lobes for detecting chemicals.

What is the pharynx used for?

Feeding (extends out of body).

What type of digestive system do planarians have

incomplete (one opening)

What are ventral nerve cords?

Nerve structures running along the body.

What are ganglia?

Clusters of nerve cells (primitive brain).

What phylum does a clam belong to?

Mollusca

What is the umbo?

Oldest, rounded part of the shell near the hinge.

What is the hinge?

Where the two shells connect.

What are valves?

The two shell halves (left and right).

What is the mantle?

Tissue that secretes the shell.

What are gills used for?

Gas exchange and feeding.

What is the foot used for?

Movement/burrowing.

What is the visceral mass?

Contains internal organs.

What do adductor muscles do?

Open and close the shell.

What phylum does an earthworm belong to?

Annelida

What is segmentation in earthworms?

Body divided into repeating segments.

What is the clitellum?

Thickened reproductive segment

What is the prostomium?

Lip-like structure over the mouth.

What is the function of the crop?

Storage of food.

What is the function of the gizzard?

Grinding food.

What is the intestine used for?

Digestion and absorption.

What are the hearts (aortic arches)?

Pump blood through the body.

What are seminal vesicles?

Produce sperm.

What are seminal receptacles?

Store sperm from another worm.

Which phylum has no true tissues?

Porifera

Which phylum has radial symmetry?

Cnidaria

Which phylum is acoelomate?

Platyhelminthes

Which phylum has a true coelom and segmentation?

Annelida

Which phylum includes animals with shells and a mantle?

Mollusca