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Flashcards in Chapter 7 Deck (15)
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1
Q

The ciliated larva if the cnidarians is called a _______

A

Planula

2
Q

True/False

The freshwater Hydra has a medusa stage in its life cycle

A

False

3
Q

Nematocysts are expelled when

A

The internal hydrostatic pressure increases when water enters due to osmotic pressure inside

4
Q

The body wall of a Hydra consists of an outer epidermis and an inner gastrodermis with _________ between them

A

Mesoglea

5
Q

Digestion in cnidarians is

A

Both extracellular and intracellular

6
Q

The structure of the nervous system in cnidarians is referred to as a __________

A

Nerve net

7
Q

True/False

The Anthozoa include the marine sea anemones and corals

A

True

8
Q

True/False

All ctenophores are marine, and most of them are free-swimming forms

A

True

9
Q

True/False

The central nervous system of cnidarians includes a brain

A

False

10
Q

True/False

Cnidarians are widespread in marine habitats, but there are a few freshwater forms

A

True

11
Q

In cnidarians, extracellular digestion occurs in the

A

Gastrovascular cavity

12
Q

The class of cnidarians with the most conspicuous medusa stage is

A

Scyphozoa

13
Q

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

A

Medusoid

14
Q

A common characteristic of cnidarians is

A

Dimorphism and often polymorphism

15
Q

True/False

The anthozoans include the marine sea anemones and corals

A

True