Cnidaria (hydras, jellyfish)

Question 1

symmetry

Answer 1

radial symmetry

Question 2

body plan

Answer 2

• simple tissue
• epidermis (outside)
  -gastrodermis
  -mesoglea
  -nerve cells

Question 3

epidermis

Answer 3

-some are contractile
-some are nematocytes
nematocytes:
stinging hairs
cnidoblast/cnidocytes
-nematocytes discharge barbed hairs with toxic compounds
used to capture prey or for defense
found on tentacles (cnidoblast)

Question 4

gastrodermis

Answer 4

-layer of cells in the gastrovascular cavity
-rudimentary digestive system
-no anus
-sac like
-secrete digestive enzyme
- mouth surrounded by tentacles

Question 5

mesoglea

Answer 5

-gelatinous layer between epidermis and gastrodermis

Question 6

nerve cells

Answer 6

• simple net throughout the body
• transmit signals to contractile cells allowing body to contract and expand
  -used for locomotion of organisms

Question 7

polymorphic organisms

Answer 7

2 stages
1. polyp-sessile stage (stationary)
2. medusa- motile stage

Question 8

polyp stage

Answer 8

• tubular
• mouth surrounded by tentacles
• posterior attached to substrate

Question 9

medusa stage

Answer 9

• bell shaped
• mouth surrounded by tentacles
• free floating

Question 10

reproduction

Answer 10

asexual
-budding
sexual
-medusa (gonads produce sperm + egg)
-polyp
spermaries- tentacles, sperm
ovaries- basal disc, egg
-some organisms exhibit polymorphism
- colonial form
-feeding polyp
- reproductive polyp

Question 11

classes

Answer 11

hydrozoa (hydroids)
scyphozoan (jelly fish)

Question 12

hydrozoa

Answer 12

-polyp dominant stage

Question 13

scyphozoa

Answer 13

• medusa dominant stage
  -panula- larvae from zygote
  -strobila- non feeding sessile polyp
• medusa- motile feeding stage