33 Test Flashcards
Why are spongin and spicules important to a sponge?
They provide support
Which of the following descriptions best fits a “sessile” organism.
attached to surface and does not move
What is the jellylike substance that separates the two layers of the body wall in sponges
mesohyl
What creates the flow of water through a sponge?
beating flagella on choanocytes
Choanocytes perform all of the following functions EXCEPT
distributing nutrients throughout the rest of the body
Sponges eliminate carbon dioxide and cellular wastes by
allowing them to diffuse into the water that passes through the sponge
A flood-filled ball of amoebocytes surrounded by a protective coat made of organic material and spicules is called a ____________.
gemmule
A _____________ is an immature stage of an animal that is usually very different in form from the adult.
Larva
Sponges have no gastrula stage.
True
Self-fertilization often happens in hermaphroditic species of sponges.
False
Which class of cnidarians has no medusa stage?
Anthozoa
Hydras and anemones are both
Sessile
Cnidarians and ctenophores are more complex than sponges because, unlike sponges, they have
Tissues and Organs
The structure that coordinates the complex activities of a cnidarian’s body is the
Nerve Net
An example of a cnidarian in the class Hydrozoa is a
Portuguese man-of-war
