Chapter 7 Flashcards
The ciliated larva if the cnidarians is called a _______
Planula
True/False
The freshwater Hydra has a medusa stage in its life cycle
False
Nematocysts are expelled when
The internal hydrostatic pressure increases when water enters due to osmotic pressure inside
The body wall of a Hydra consists of an outer epidermis and an inner gastrodermis with _________ between them
Mesoglea
Digestion in cnidarians is
Both extracellular and intracellular
The structure of the nervous system in cnidarians is referred to as a __________
Nerve net
True/False
The Anthozoa include the marine sea anemones and corals
True
True/False
All ctenophores are marine, and most of them are free-swimming forms
True
True/False
The central nervous system of cnidarians includes a brain
False
True/False
Cnidarians are widespread in marine habitats, but there are a few freshwater forms
True
In cnidarians, extracellular digestion occurs in the
Gastrovascular cavity
The class of cnidarians with the most conspicuous medusa stage is
Scyphozoa
Molecular evidence suggests that hydrozoans, scyphozoans, and cubozoans shared a common ancestor with an Anthozoan life cycle and a _______ form later to the life cycle
Medusoid
A common characteristic of cnidarians is
Dimorphism and often polymorphism
True/False
The anthozoans include the marine sea anemones and corals
True
