Lecture 20

Question 1

What type of group are invertebrates?

Answer 1

Paraphyletic

Question 2

Phylum Portifera (sponges) traits?

Answer 2

Lack hox genes
Do not move
No tissue or organs
Structural support comes from spicules

Question 3

Mesohyl?

Answer 3

gelatinous acellular layer between outer skin and choanacyte layer (not a tissue)

Question 4

Filter feeding?

Answer 4

Food particles engulfed by phagocytosis at base of choanocyte cell
Amoebocytes nudge up and take food to other cells

Question 5

Reproduction of sponges?

Answer 5

Hermaphroditic

External and internal fertiliz

Question 6

Eggs in sponge arise from?

Answer 6

amoebocytes

Question 7

Sperm in sponges arise from?

Answer 7

choanocytes

Question 8

Fertilized in?

Answer 8

Mesohyl

Question 9

Phylum cnidaria traits?

Answer 9

True differentiated tissues
Radial symmetry
Diploplastic
Organs are tissues for different tasks
House algae

Question 10

Cnidaria has?

Answer 10

jellyfish, hydras, anemones, corals

Question 11

Two body forms of Cnidaria?

Answer 11

Polyp and Medusa

Question 12

Polyp?

Answer 12

Sessile form with oral end upward, attached to substrate

Question 13

Medusa?

Answer 13

Motile form, oral end down, moves freely in water (hydrostatic skelly)

Question 14

Cnidocytes carry?

Answer 14

Nematocysts

Question 15

Nematocysts?

Answer 15

Sting