Topic 21: Porifera and Cnidaria

Question 1

Phylum Porifera (Sponges)

Answer 1

Basal animals that lack true tissues, Sessile but have motile larvae, No internal organs, muscles, nervous, or circulatory system.

Question 2

Spicules

Answer 2

Structural support, tiny needles or rods of silica or calcium carbonate.

Question 3

Spongin

Answer 3

Structural support made of fibrous collagen protein networks.

Question 4

Choanocytes Trait

Answer 4

They generate water currents by beating their flagella and capturing suspended food particles. (Collar cells)

Question 5

Epidermal Cells

Answer 5

Impermeable outer layer

Question 6

Porocytes

Answer 6

They have tubular cells that make up the pores of a sponge, allowing water to flow through.

Question 7

Suspension Feeders

Answer 7

Water is drawn into a cavity called spongocoel and out through an opening (osculum). Extract food using mucus-covered microvilli, engulfed through phagocytosis and digested.

Question 8

Mesohyl

Answer 8

Separates the choanocyte and epidermis. Gel-like matrix used to transport nutrients to other cells.

Question 9

Sponge Reproduction

Answer 9

Hermaphrodites and use internal fertilization. Don’t have gonads. Can have asexual reproduction.

Question 10

Sponge Sperm

Answer 10

Develops from choanocytes

Question 11

Sponge Eggs

Answer 11

Develop from amoebocytes

Question 12

Clade Eumetazoa

Answer 12

All animals excluding sponges, characterized by the presence of true tissues.

Question 13

Phylum Cnidaria

Answer 13

Jelly fish, corals, etc. Radial and diploblastic w/ a sac with a gastrovascualr gavity with a single opening functioning as both mouth and anus surronded by tentacles with stinging cells.

Question 14

Cnidarian Feeding

Answer 14

Predators use tentacles to capture prey. Have cnidocytes; explosive cells that contain complex organelles (nemotocysts) that deliver toxins to prey.

Question 15

Mesoglea

Answer 15

Non-living jelly that separates the epidermis and gastrodermis.

Question 16

Inner Gastrodermis

Answer 16

Lines the gastrovascular cavity and arises from the endoderm.

Question 17

Polyp

Answer 17

Sessile form w/ oral end upwards.

Question 18

Medusa

Answer 18

Motile w/ hydro static skeleton w/ oral end downwards.

Question 19

Clade Medusozoa

Answer 19

Produce medusa stage in their life cycle.

Question 20

Clade Medusozoa - Hydrozoans

Answer 20

Alternates between polyp and medusa forms.

Question 21

Clade Medusozoa - Anthozoa

Answer 21

Only occur as sessile solitary or colonial polyps. Corals, etc.

Question 22

Scyphozoans

Answer 22

Jelly fish

Question 23

Cubozoans

Answer 23

Box Jellyfish.