Unit 5 Terms - Cnidaria and Ctenophora

Question 1

• Name means “water serpent animal”
• includes: Hydra, Obelia, Physalia
• medusa have velum

Answer 1

Class Hydrozoa

Question 2

• name means “ cup-animal”
• includes: Aurelia
• no velum in medusa

Answer 2

Class Scyphozoa

Question 3

• name means “flower animal”
• includes: corals (like: Gorgonia and Tubipora) and anemones (like: Metridium)
• no medusa stage

Answer 3

Class Anthozoa

Question 4

an explosive cell containing one giant secretory organelle or cnida

Answer 4

cnidocyte

Question 5

• organelle that can be discharged from its cell
• can be stinging or adhesive
• more than 20 varieties, but most common is nematocyst

Answer 5

cnida (plural = cnidae)

Question 6

• stinging cnida
• used to inject toxin

Answer 6

nematocyst

Question 7

lid-like feature on a nematocyst

Answer 7

operculum

Question 8

trigger on a nematocyst, made from a modified cilium

Answer 8

cnidocil

Question 9

a diffuse nervous system, nerve cells equally dispersed around the body

Answer 9

nerve net

Question 10

the root-like base seen in a colonial hydrozoa such as Obelia

Answer 10

hydrorhiza

Question 11

the stalk of a colonial hydrozoa such as Obelia

Answer 11

hydrocaulus

Question 12

the inner, living/cellular part of the stalk (hydrocaulus)

Answer 12

coenosarc

Question 13

the outer, non-living chitinous sheath of the hydrocaulus

Answer 13

perisarc

Question 14

the feeding polyp seen in a colonial hydrozoa such as Obelia

Answer 14

hydranth

Question 15

reproductive polyps seen in a colonial hydrozoa such as Obelia

Answer 15

gonangium

Question 16

a shelf projecting inward from the margin of the bell in a medusa

Answer 16

velum

Question 17

tubular extension for mouth; often seen in medusa of Hydrozoa

Answer 17

manubrium

Question 18

specialized sense organ for equilibrium

Answer 18

statocyst

Question 19

light-sensitive organ

Answer 19

ocelli

Question 20

conical elevation that bears mouth; seen in Hydra

Answer 20

hypostome

Question 21

• when chemical breakdown of food takes place outside of cells
• digestive enzymes breakdown food particles in a body cavity

Answer 21

extracellular digestion

Question 22

food particles are drawn into cells by pseudopodia and then chemically broken down with the cell

Answer 22

intracellular digestion

Question 23

• columnar cells with laterally extended bases
• found lining the gastrovascular cavity
• the bases form a circular muscle layer

Answer 23

nutritive muscular cells

Question 24

• cells that make up most of the epidermis
• serve as both a covering and as a longitudinal muscle layer

Answer 24

epitheliomuscular cells

Question 25

* cells that are undifferenitated * can transform into other types of cells if necessary

Answer 25

interstitial cells

Question 26

cnidocytes with cnidae that penetrate prey and inject toxin

Answer 26

penetrant

Question 27

cnidocytes with cnidae that recoil and entangle prey

Answer 27

volvent

Question 28

cnidocytes with cnidae that secrete adhesive substances for attachement

Answer 28

glutinant

Question 29

method of asexual reproduction in most cnidarians

Answer 29

budding

Question 30

**ciliated, free-swimming larva** seen in most Scyphozoan jellies like *Aurelia*

Answer 30

planula

Question 31

* part of the life cyle of Scyphozoan jellies like *Aurelia* * **hydra-like polyp** * may bud to produce polyp clone

Answer 31

scyphistoma

Question 32

* part of the life cyle of Scyphozoan jellies like *Aurelia* * **made up of a series of cup-like buds**

Answer 32

strobila

Question 33

* part of the life cyle of Scyphozoan jellies like *Aurelia* * **individual saucer-like buds produced by strobilation**

Answer 33

ephyra

Question 34

* small pieces of a pedal disc break off and become new individuals * asexual reproduction seen in anthozoans like the anemones

Answer 34

pedal laceration

Question 35

dinoflagellates found living as benefitial partners with many cnidarians like corals

Answer 35

zooxanthellae

Question 36

when corals lose their zooxanthellae and become white and brittle

Answer 36

coral bleaching

Question 37

a reef close to a landmass either with no lagoon or a narrow lagoon

Answer 37

fringing reef

Question 38

a reef with a wide lagoon between it and the shore

Answer 38

barrier reef

Question 39

a reef that encirlces a lagoon but there is no landmass or island anymore

Answer 39

atoll