Phylum Cnidaria

Question 1

what is the habitat of the cnidaria

Answer 1

1. mostly marine, some freshwater

2. mostly shallow water animals

Question 2

are cnidaria predators or prey

Answer 2

all are predators

Question 3

are cnidaria fast or slow movers

Answer 3

slow movers, mostly passive movers

Question 4

how old are cnidaria fossils

Answer 4

almost 700 million years old from the precambrien period

Question 5

what type of symmetry do cnidarians have

Answer 5

radial

Question 6

what are the 2 ends of a cnidaria organism

Answer 6

oral and aboral

Question 7

what is a cnidocyte

Answer 7

a cell with a stinging organelle called a nemtocyst

Question 8

how do cnidaria sting prey

Answer 8

penetrating and envenomating them

Question 9

what level of organization do cnidaria have

Answer 9

cell-tissue grade

Question 10

what is a unique feature of the nerve cells in cnidaria

Answer 10

bidirectional

Question 11

when an organism has radial symmetry, what does that mean with regards to their nervous system

Answer 11

decentralized nervous system

Question 12

when an organism has bilateral symmetry and directional movement, what type of nervous system do they have

Answer 12

centralized symmetry

Question 13

what is a nerve net

Answer 13

nerve cells connect to muscular cells forming a coordinated neuromuscular system

Question 14

what is the cnidaria body plan

Answer 14

1. digestive sac with one opening meaning a two-way digestive system
2. Diploblastic: ectodermis and endodermis
3. mesoglea between two tissue layers
4. inner cavity is gastrovascular for digestion and circulation

Question 15

Cnidaria are polymorphic, what are the two types

Answer 15

1. polyp: sessile

2. medusa: mobile jellyfish form