Quiz 2 - Phylum Cnidaria

Question 1

What do interstitial cells (totipotent cells) do in cnidaria

Answer 1

Make gametes and cnidocytes

Question 2

What are the receptor cells in cnidaria?

Answer 2

Sensory cilium

Make a loose nerve net

Question 3

Epithilio-muscular cells function as skin and muscle in cnidaria. What do they contain that are longitudinal in the epidermis but circular in the gastrodermis?

Answer 3

Myofibrils

Question 4

What class are the true jellyfish

Answer 4

Scyphozoa

Question 5

What have a thick mesoglea, found mostly in the medusa stage, are active carnivores with a well developped gastrovascular cavity

Answer 5

Scyphozoa

Question 6

What is the manubrium in scyphozoa?

Answer 6

Underside of the bell, stalk like structure that hangs down the centre, with the mouth at is tip

There are usually four arms attached to the manubrium

Question 7

Explain the aurelia life cycle of class scyphozoa

Answer 7

Planula - scyphisotoma - stobilation - ephyra - medusa

Question 8

Explain in detail the different stages of scyphozoa life cycle

Answer 8

Planula - fertilized eggs w cilia, that turn into a polyp, free swimming larva
Scyphistoma - asexul budding of the polyp, turns into a segmenting polyp
Strobilation - tentacles reabsorbed, body starts to narrow
Ephyra - baby medusa stage, start breaking off
Medusa - adult jellies, sexual

Question 9

What class are the box jellies

Answer 9

Cubozoa

Question 10

Whats a defining feature of cubozoa

Answer 10

4 tentacles from 4 corners

No stobilation!!!

Question 11

What is different from class scyphozoa to class cubozoa in terms of their life cycles

Answer 11

Cubozoa- no strobilation

Mate by mono strobilation

Question 12

What is the life cycle of cubozoa

Answer 12

Mate
Planula
Settle and form polyps
Medusa

Question 13

What are the stalked jellyfish

Answer 13

Class staurozoa

Question 14

What class has an attached medusa stage and no alteration of generation (aka direct development)?

Answer 14

Staurozoa

Question 15

What class is found in mostly the polyp stage?

Answer 15

Hydrozoa

Question 16

What is the life cycle of hydrozoa

Answer 16

Mate
Planula
Polyp
Asexual reproduction of polyp

Question 17

What class is the sea anemones and the corals

Answer 17

Anthozoans

Question 18

What class has no medusa stage and a divided gastrovascular cavity (coelentron)

Answer 18

Anthozoa - corals and anemones

Question 19

What class are good circular and longitudinal muscles

Answer 19

Anthozoa

Question 20

What is a scyphisotoma in scyphozoa

Answer 20

Segmented polyp after the planula stage, when the start budding

Question 21

What are the 5 main classes of jelly / cnidaira

Answer 21

Scyphozoa
Cubozoa
Staurozoa
Hydrozoa
Anthozoa

Question 22

What are the soft corals classified under?

Answer 22

Subclass alcyonaria / octocorallia

Question 23

What are some characteristics of the octocorallia / alcyonaria

Answer 23

8 part symmetry
Soft coral / more mesoglea
Deep sea corals

Question 24

What is subclass zoantharia / hexacorallia

Answer 24

6 way symmetry anemones and hard corals

Question 25

What class are the hard corals

Answer 25

Hexacorallia

Question 26

What are the reef building corals (hermatypic) classified under

Answer 26

Hexacorallia/ zoantharia

Question 27

What is the life cycle of a coral

Answer 27

``` Hermaphroditism Sexual or asexual Broadcast spawning - corals release gametes simultaneously Make planula - then polyp Budding from oral disc / at base ```

Question 28

Where does coral budding happen

Answer 28

At the oral disc / at the base

Question 29

What is group myxozoa

Answer 29

Slime or mucus animals Parasites of fish / invertebrates

Question 30

What are the two morphological forms of myxozoa

Answer 30

Motile worm and spore forming sacs

Question 31

Do myxozoams have a gut or a nervous system

Answer 31

Nope

Question 32

Bilateral symmetry is the presence of anterior posterior and dorsal ventral - but cnidarians show oral - aboral with their mouth (blastopore) on one end. How are they bilateral animals?

Answer 32

Shows bilateral expression during embryogenesis Also, they have bilateral hox genes even though they lack morphological A-P axis

Question 33

What are the 2 major evolution events of cnidarians

Answer 33

Make axial properties Form multilayered animals through gastrolation - endoderm and ectoderm