3: Porifera, Cnidaria, and Ctenophora

Question 1

phylum:
- sessile, aquatic filter feeders
- rely on water for feeding, gas exchange, excretion

Answer 1

sponges

Question 2

large chamber in center of sponge

Answer 2

spongocoel

Question 3

large opening where water exits the spongocoel

Answer 3

osculum

Question 4

jelly-like substance that separates the outer layer of cells from the choanocytes

Answer 4

mesohyl

Question 5

mineralized structures that make up sponge’s “skeleton”

Answer 5

spongin & spicules

Question 6

important in distinguishing different classes of sponge

Answer 6

spicules

Question 7

• flagellated cells surrounded by a collar
• used for feeding and reproduction

Answer 7

choanocytes

Question 8

• solitary or colonial aquatic eukaryotes
• similar in structure to choanocytes

Answer 8

choanoflagellates

Question 9

amoeboid cells that move in the mesohyl and perform several functions

Answer 9

archaeocytes

Question 10

specialized archaeocyte: secrete spicules

Answer 10

sclerocytes

Question 11

specialized archaeocyte: secrete spongin

Answer 11

spongocytes

Question 12

• thin, flat cells that form the pinacoderm
• closest in form to true tissues
• can ingest particles through phagocytosis and regulate the sponge’s SA

Answer 12

pinacocytes

Question 13

sponge digestion occurs…

Answer 13

intracellularly

Question 14

4 classes of sponge

Answer 14

• calcarea
• hexactinellida
• demospongiae
• homoscleromorpha

Question 15

sponge class:
- spicules made up of calcium carbonate; usually needle shaped; 3-4 rays
- small
- entirely marine

Answer 15

calcarea

Question 16

sponge class:
- glass sponges
- skeleton composed of 6-rayed siliceous spicules
- often cylindrical or funnel shaped
- all marine; prefer deep water

Answer 16

hexactinellida

Question 17

• largest group of sponges
• spicules siliceous but not 6-rayed
• majority marine; one freshwater family
• varied shapes

Answer 17

demospongiae

Question 18

sponge class:
- pinacoderm has a basal lamina
- some lack spicules entirely

Answer 18

homoscleromorpha

Question 19

phylum:
- radially symmetric animals
- nearly all marine
- contains cnidocytes
- have true tissue; diploblastic; don’t contain true organs
- reproduce sexually/asexually

Answer 19

cnidaria

Question 20

specialized stinging cells in cnidarians

Answer 20

cnidocytes

Question 21

cnidarian body plan:
- adapted for sedentary life
- most have tubular bodies
- may reproduce asexually

Answer 21

polyp

Question 22

polyp in colonial cnidarians for feeding

Answer 22

gastrozooids

Question 23

polyp in colonial cnidarians for reproduction

Answer 23

gonozooids

Question 24

Cnidaria dimorphism:
- usually free-swimming
- bell/umbrella shaped bodies
- have sensory structures for orientation & light reception

Answer 24

medusa

Question 25

Body plan: - larva that cnidaria zygote develops into - attaches to a substrate and then metamorphoses into a polyp

Answer 25

planula

Question 26

- stinging cells concentrated around the mouth and tentacles - produce organelles known as cnidae

Answer 26

cnidocytes

Question 27

cnidae that administer toxins for feeding and defense

Answer 27

nematocysts

Question 28

serves as trigger in all cnidarians excepts anthozoa

Answer 28

cnidocil

Question 29

- incomplete gut - often branched/ divided w septa - opening surrounded by tentacles - shared in colonial cnidarians

Answer 29

gastrovascular cavity

Question 30

outer epidermis and inner gastrodermis w mesoglea in between (cnidarians)

Answer 30

body wall

Question 31

jelly-like extracellular matrix in cnidarians

Answer 31

mesoglea

Question 32

scattered network where nerve cells are organized in cnidarian simple nervous system

Answer 32

nerve net

Question 33

groups of nerves that house sensory receptors

Answer 33

rhopalia

Question 34

6 classes of cnidarians

Answer 34

- hydrozoa - scyphozoa - staurozoa - myxozoa - cubozoa - anthozoa

Question 35

cnidaria class: - solitary or colonial organisms w a dominant polyp form - ex: hydra, portuguese man o' war

Answer 35

hydrozoa (hydras)

Question 36

hydra; can revert back to polyp stage of their development in response to damage or starvation (transdifferentiation)

Answer 36

turritopsis

Question 37

cnidaria class: - true jellyfishes - dominant medusa form w a bell-like shape - margin of bell has 8 notches w rhopalia - "cup animals"

Answer 37

scyphozoa

Question 38

cnidaria class: - ex: box jellyfish - dominant medusa stage that is box-shaped rather than bell-shaped - each corner of umbrella has a tentacle/s hanging from a pedalium - "box animals"

Answer 38

cubozoa

Question 39

small and highly venomous box jellyfish

Answer 39

irukandji jellyfish

Question 40

cnidaria class: - flower-like polyps - don't have medusa stage - can be solitary or colonial - "flower animals"

Answer 40

anthozoa

Question 41

3 subclasses of anthozoa

Answer 41

- hexacorallia - ceriantipatharia - octocorallia

Question 42

anthozoa subclass: - contains sea anemones and hard/true corals - hexamerous body plan

Answer 42

hexacorallia

Question 43

From hexacorallia: - large polyps - gastrovascular cavity is divided into 6 chambers by 6 pairs of mesenteries - form mutualistic relationships w several organisms

Answer 43

sea anemonies (actinaria)

Question 44

From hexacorallia: - anemone-like polyps living in a calcium carbonate exoskeleton - epidermis at base secretes exoskeleton

Answer 44

true corals (scleractinia)

Question 45

anthozoa subclass: - unpaired mesenteries - can be solitary (tube anemones) or colonial (black corals)

Answer 45

subclass ceriantipatharia

Question 46

anthozoa subclass: - soft and gorgonian corals - octomerous body plan - all colonial

Answer 46

octocorallia

Question 47

series of tubes that connect gastrovascular cavities of each polyp

Answer 47

solenia

Question 48

- reef-building corals - require warm temps, light, high salinity

Answer 48

hermatypic

Question 49

large formations of limestone in shallow, tropical seas deposited by organisms over thousands of years

Answer 49

coral reefs

Question 50

mutualistic dinoflagellates that need light

Answer 50

zooxanthellae

Question 51

occurs when the loss of zooxanthellae turns corals white and brittle

Answer 51

coral bleaching

Question 52

phylum: - comb jellies - have 8 rows of comblike plates of cilia for movement - complete gut - entirely marine - mostly monoecious - similar nerve network to cnidarians

Answer 52

cteneophores