LESSON 8: PHYLUM CNIDARIA

Question 1

alternatively referred to as coelenterates; their distinguishing feature is cnidocytes, specialized cells present on the tentacles that is used for capturing prey and defense

Answer 1

Phylum Cnidaria

Question 2

found in organisms which show morphological features, internal or external, of both bilateral and radial symmetry

Answer 2

biradial symmetry

Question 3

cup-like in appearance; composed a cylindrical body known as the column, and a mouth surrounded by
food-gathering tentacles facing upwards; a much primitive form of cnidarians that lack sensory organs; seen in sea anemone, hydra, and corals

Answer 3

Polyp

Question 4

umbrella-like in appearance; more developed form of cnidarians; seen in jellyfishes

Answer 4

Medusa

Question 5

functions in digestion, the exchange of respiratory gases and metabolic wastes, and the discharge of gametes; presence of a body wall which encloses a cavity

Answer 5

gastrovascular cavity

Question 6

tentacles that have specialized stinging cells, which have nematocysts used to capture prey, ward off enemies, or anchorage

Answer 6

cnidoblasts

Question 7

outer layer of the body wall

Answer 7

epidermis

Question 8

inner layer of the body wall

Answer 8

gastrodermis

Question 9

sometimes referred to as the mesohyll; gelatinous substance between the epidermis and the gastrodermis; mostly composed of water, it also includes fibrous proteins like
collagen, as well as muscle bundles and nerve fibers

Answer 9

Mesoglea

Question 10

also known as cnidocytes or cnidoblast;

Answer 10

Nematocytes

Question 11

long tube armed with spines that can deliver paralyzing toxins and
immunological reactions in the envenomated organism; the venom contains enzymes, potent pore
forming toxins, and neurotoxins

Answer 11

Nematocysts

Question 12

also referred to as the class of hydra; acknowledged as the most diverse group of cnidarians

Answer 12

Class Hydrozoa

Question 13

commonly known as to as the class of true jellyfishes; medusa form dominates the life cycle; characterized by the presence of short or long tentacles with nematocysts; have a ring of muscles that lines the dome of their bodies; these structures provide them with the contractile force they need to 
swim through water

Answer 13

Class Scyphozoa

Question 14

alternatively recognized as to as the class of box jellyfishes; can produce an extremely potent venom

Answer 14

Class Cubozoa

Question 15

also known as to as the class of sea anemones and corals; mouth surrounded by tentacles with nematocysts; commonly polyps and have limited locomotion

Answer 15

Class Anthozoa