Lab 1 Vocab

Question 1

Sessile

Answer 1

Adhere to substrate

Question 2

Asymmetrical

Answer 2

Poriferans are asymmetrical. No symmetry

Question 3

Pinoacytes

Answer 3

Cells that line outer surface of sponge

Question 4

Mesenchyme cells

Answer 4

Amoeboid cells that secrete skeletal elements (spicules or spongin) to form loosely-organized mesohyl layer. Involved in food storage/transport and reproduction.

Question 5

Choanocytes

Answer 5

“Collar cells” flagellated cells (probs from choanoflagellates) circulate water within sponge for movement of gametes , gas exchange and waste removal (diffusion across cell membrane) and feeding.

Question 6

How ocean became oxygenated

Answer 6

Collar of choanocyte is ring of microvilli that surrounds flagellum. Small organic food particles are trapped in microvilli while flagellum moves water. removal of these particles stops them from decaying on ocean floor and consuming oxygen

Question 7

Radially symmetrical

Answer 7

Split in two (think flower pot)

Question 8

Bilaterally symmetrical

Answer 8

Two symmetrical halves

Question 9

Diploblastic

Answer 9

Two-layered body structure (epithelial layer, gelatinous mesoglea, gastrodermis)

Question 10

Hydrostatic skeleton

Answer 10

gastrovascular cavity of cnidarians. support and movement.

Question 11

Cnidocyte

Answer 11

stinger (also for entanglement and attachment)

Question 12

nematocyst

Answer 12

present in cnidocyte, injects toxin into victims

Question 13

polyp

Answer 13

tentacles surround mouth which is up

Question 14

Medusa

Answer 14

“jellyfish”, tentacles surrounding mouth on bottom

Question 15

alternation of generations

Answer 15

two life forms with complex life cycles

Question 16

planula

Answer 16

free-swimming ciliated larva of cnidarians. attaches itself to a substrate and becomes polyp

Question 17

Phylum Cnidaria

Answer 17

think jellyfish/polyps

Question 18

Class anthozoa

Answer 18

Think anenomes and corals. only polyps. cnidocytes only on gastrodermis.

Question 19

Coral reefs

Answer 19

corals + symbiotic association with zooxanthellae algae

Question 20

Class scyphozoa

Answer 20

mostly medusa, true jellyfish. cnidocytes on epidermis and gastrodermis

Question 21

Class hydrozoa

Answer 21

hydra, small and have cnidocyes only in epidermis. no medusa stage. as a polyp reproduces sexually and asexually (budding when food is plentiful)

Question 22

Hydra feeding

Answer 22

Small crustaceans. water currents move prey to them, in the tentacles nematocysts discharge to paralyze the animal. tentacles shorten to bring food to the mouth.