Lab 2 - Platyhelminthes and Digestion

Question 1

What clade of Metazoa are Platyhelminthes part of and why?

Answer 1

Bilateria because they all have bilateral symmetry

Question 2

What synapomorphy arose due to Platyhelminthes’ symmetry?

Answer 2

Cephalization

Question 3

What is Cephalization

Answer 3

The development of sensory organs and a complex nervous system at the head

Question 4

What kind of coleom do Platyhelminthes have?

Answer 4

None (Acoleomate)

Question 5

Two clades in Platyhelminthes

Answer 5

Tuberillia (paraphyletic) and Neodermata

Question 6

What characteristic separates the two clades in Platyhelminthes

Answer 6

The development of a syncitial tegument, which is a large mass of fused cells

Question 7

What taxa did we study in Tuberillia? What is characteristic of each one?

Answer 7

Polycladidia and Tricladidia. Polycladidia has a multi-branched intestine whereas Tricladidia has a three branched intestine (1 anterior, 2 posterior)

Question 8

What taxa did we study in Neodermata?

Answer 8

Trematoda, Cestoda

Question 9

Trematode Species was….

Answer 9

Chlonorchis

Question 10

When planaria is treated with LiCl, what happens

Answer 10

Cillia does not respond

Question 11

When planaria is treated with MgCl2, what happens

Answer 11

Muscles do not contract

Question 12

Proventriculus

Answer 12

Anterior portion in pigeon digestive tract, anterior to the gizzard

Question 13

Cecae

Answer 13

blind pouches at end of intestine

Question 14

Cloaca

Answer 14

rectum

Question 15

What handles the food in arthropods

Answer 15

labial palps

Question 16

What masticates the food in arthropods

Answer 16

mandibles

Question 17

Where does most nutrient absorption take place

Answer 17

Midgut

Question 18

Where does most water absorption take place

Answer 18

Hindgut (colon)