Test 3-Cnidaria

Question 1

Environment or Habitat

Answer 1

aquatic, mostly marine but some freshwater (Hydra)

Question 2

Common representatives

Answer 2

jellyfish, coral, sea anemones

Question 3

Cyst-

Answer 3

cell

Question 4

Nerve net

Answer 4

nervous system

Question 5

Nerma-

Answer 5

thread

Question 6

Diploblastic

Answer 6

tentacles and bodies consist of two layers of cells

Question 7

Cnidoblast

Answer 7

the “stinging cells”

nematocysts, spirocyst, ptychocysts

Question 8

Single body opening

Answer 8

mouth and anus

Question 9

Uncephalized

Answer 9

no brain

Question 10

Symmetry

Answer 10

radial and bilateral

Question 11

Mode of living

Answer 11

sessile (coral)
free living (jellyfish, medusa)

Question 12

Complexity

Answer 12

tissues but no organs, two layers of skin

digestive system on inside-skin on outside

Question 13

Stinging

Answer 13

when something touches it, it’s like a lever and shoots out thread with toxin for defense

Question 14

2 life forms

Answer 14

polyp: sessile
medusa: free living
spend time in both forms

Question 15

Life Cycle/Reproduction

Answer 15

both sexually and asexually (budding [polyp], stolonic outgrowth and other processes)
coral usually reproduce all on the same day (throw sperm)

Question 16

Importance to humans

Answer 16

food (Asia and North America) 
coral skeletons are used in building materials (cement)
jewelry (coral skeletons)
toxins (can be fatal) 
slow down waves (prevent erosion)

Question 17

Subgroups

Answer 17

Hydra, Man-o-War
Jellyfish, medusa
coral, anemone

Question 18

Complexity

Answer 18

Simple

Question 19

Nearest relatives

Answer 19

ctenophora phylum (don’t have stinging cells)

Question 20

Cnidos-

Answer 20

nettles (plant)