Porifera, Cnidaria and Cetnophora

Question 1

what group do porifera belong to?

Answer 1

metazoa

Question 2

what are Porifera?

Answer 2

sponges

Question 3

how many porifera species?

Answer 3

5500

Question 4

what do porifera lack?

Answer 4

true tissue

Question 5

How many Cnidaria species?

Answer 5

10,000

Question 6

Cnidaria characteristics? tissue/symmetry etc

Answer 6

true tissue
radial symmetry
diploblastic
variation in body plan
no brain
nerve net for movement coordination

Question 7

what does diploblastic mean?

Answer 7

2 germ layers - endoderm and ectoderm

Question 8

examples of cnidarians

Answer 8

corals, anemones and jellies
barrel jellyfish

Question 9

cnidarian muscle and nerve net

Answer 9

bundles of microfilaments arranged into contractile fibres in the epidermis - allows response to external stimuli

Question 10

how do cnidarians feed?

Answer 10

carnivorous
tentacles capture prey, passed to gastrovascular cavity
extra-cellular digestion

Question 11

what is a homologous trait for cnidarians?

Answer 11

capsule like organelles

Question 12

what are nematocysts?

Answer 12

specialised cnidae that produce stinging threads that penetrate body wall of prey

Question 13

Modern Cnidaria divided into 4 classes, what are they?

Answer 13

anthozoans
hydrozoans
scyphozoans
cubozoa

Question 14

what is polyp?

Answer 14

a type of body plan, attached to substrate with tentacles on the top

Question 15

what is medusa?

Answer 15

a type of body plan that is mobile in form with tentacles at the bottom

Question 16

characteristics of hydrozoa

Answer 16

e.g hydras and hydroids
alternate between polyp and medusa stages
hydra = highly regenerative, don’t show senescence

Question 17

characteristics of scyphozoa

Answer 17

‘jellyfish’ - true jellies and sea nettles
all marine
most larger jellyfish (2m diameter)
medusa = most prominent
bioluminescent

Question 18

characteristics of cubozoa

Answer 18

box jellies and sea wasps
all marine
strong swimmers
active hunters
toxins target vertebrates - potent venom

Question 19

characteristics of anthozoa

Answer 19

flower animals
corals and anemones
only occur as polyps
lots of nutrition via photosynthesis

Question 20

what are ctenophores?

Answer 20

comb jellies - e.g sea gooseberry

Question 21

how many species of ctenophores?

Answer 21

roughly 100

Question 22

characteristics of ctenophores

Answer 22

all marine
radial symmetry
diploblastic
long branched tentacles with colloblast cels (sticky)
all hermaphrodites
many bioluminescent