CNIDARIA

Question 1

Cnideria; whats the greek meaning?

Answer 1

a stinging thread

Question 2

Cnideria; which type of animals?

Answer 2

jellies, corals, sea anemones, hydroids

Question 3

when did cnideria emerge?

Answer 3

800 mya

Question 4

why do we regard Cnidaria as simple?

Answer 4

• no head end
• mouth=anus
• mouth surrounded by tentacles
• radial symmetry
• diploblastic
• nerves (no brain or CNS)

Question 5

what tissue replaces mesohyl (porifera) in cnideria?

Answer 5

mesoglea

Question 6

mesoglea

Answer 6

middle-jelly

Question 7

what are all cells in contact with?

Answer 7

the environment

Question 8

cell movement in cnidaria

Answer 8

• migratory stem cells (all cells are stem cells)

- nematocysts, nerve cells and gonads

Question 9

what are the four class or cnidaria?

Answer 9

Anthozoa
-anemones, corals
Hydrozoa
-Hydroids
Scyphozoa
-Jellyfish
Cubozoa
-box jellyfish

Question 10

What stage (medusa/polyp) is dominant for each class of Cnidaria?

Answer 10

Anthozoa: no medusa stage. polyp.
Hydrozoa: medusa and polyp
Scyphozoa: medusa
Cubozoa: medusa

Question 11

in which other phyla can you find nematocysts?

Answer 11

mollusca (nudibranch)
ctenophores
platyhelminthes
kleptocnidae

Question 12

microsporidia and myxosporidia

Answer 12

protist origins of cnidaria. both parasitic, and either protist or fungi now

Question 13

nerve conduction

Answer 13

• response times are slow
• concentration is slower
• can be up to 2 minutes before reaction

Question 14

locomotion- anthozoa

Answer 14

• may shuffle, burrow or swim
• contract muscle by coelenteron
• pharynx, siphonoglyph

Question 15

locomotion- scyphozoa

Answer 15

-tentacles
-change body shape
-medusa vs polyp
-muscle contraction and a skeleton
hydrostatic
mesoglea
contraction o striated muscles
ringed nerve cells

Question 16

locomotion- hydrozoa

Answer 16

-velum. principle of continuity. (hose with your finger on it. thats how this animal moves)

Question 17

locomotion- cubozoa

Answer 17

• rapid
• they sleep!
• 8 camera eyes
• nerve ring connection
• rhopalium
• hunt, kill, close to shore (danger!)

Question 18

how do cnidaria reproduce?

Answer 18

sexually and asexually.
ALTERNATION OF GENERATIONS.
Medusa>Polyp

Question 19

how do anthozoa reproduce?

Answer 19

Sexual:
broadcast spawning; fertilization in the water column.
Asexual:
logitudinal fission (split in 2)
parthenogenesis (basal laceration, internal basal laceration, brooding)

Question 20

Hydrozoa; reproduction

Answer 20

• dioecious adults
• egg + sperm
• fertilization
• planula larvae
• settlement
• polyp colony growth

Question 21

Scyphozoa; reproduction

Answer 21

• dioecious adults
• egg
• scyphisotoma
• ephyra

Question 22

Cubozoa; reproduction

Answer 22

• dioecious
• pairs
• embryo
• planula
• polyp
• budding
• metamorphose

Question 23

the three general formations of cnidaria

Answer 23

• polyp and medusa forms
• colony formation
• coral formation

Question 24

4 parts of medusa anatomy

Answer 24

• bell
• gonads
• nerve ring
• radiating canal

Question 25

acrorhagi

Answer 25

concentations of cnidae - polyp/medusa

Question 26

acontia

Answer 26

threadlike defensive organs, composed largely of cnidae, thrown out of the mouth or special pores when irritated.

Question 27

is medusa the asexual or sexual phase?

Answer 27

sexual

Question 28

statocyst

Answer 28

balancing organ

Question 29

manubrium

Answer 29

mouth

Question 30

what is an example of polymorphism?

Answer 30

snail fur, hydractinia

Question 31

main distinguishing feature of coral

Answer 31

lays down calcium carbonate

Question 32

what phylas are kleptocnidae?

Answer 32

- mollusca - platyhelmenthes - ctenophores