Chapter 33 (Module 2)

Question 1

Definition of an invertebrate (4):

Answer 1

1. Animals that lack a backbone
2. Account for 95% of known animal species
   3, Occupy almost every habitat on Earth
3. Microscopic and very large

Question 2

Phyla Porifera: body plan and parts

Answer 2

• No tissues, asymmetrical
• Chanocytes
• Mesohyl
• Amoebocytes

Question 3

Chanocytes =

Answer 3

flagellated color cells that engulf bacteria and for particles by phagocytosis

Question 4

Mesohyl =

Answer 4

gelatinous region separating two layers of cells

Question 5

Amoebocytes =

Answer 5

cells within the mesohyl digest for, transport nutrients, and make skeletal fibers

Question 6

Phylum Porifera (continued):

Answer 6

Most are hemaphrodites, zygotes develop into flagellated, swimming larvae, larvae eventually settle and develop into sessile adults

Question 7

Phylum Cnidaria: body plan and two forms

Answer 7

JELLYFISH(nerve net, one opening)
- Radial symmetry
- Diploblastic
- No body cavity (bc no mesoderm)
1. Polyps
2. Medusas

Question 8

Polyps (sessile):

Answer 8

adhere to substrate by the end opposite their mouth

Question 9

Medusas (motel):

Answer 9

free-swimming, bell shaped body with mouth on underside

Question 10

Phylum Protostomes has 2 subdivisions

Answer 10

• Lophotrochozoa
• Ecdysozoa

Question 11

Phylum