Classes of Cnidaria: Hydrozoa

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What is the main characteristic of the Coelenteron in the Class Hydrozoa?

It has a complex stomodeum (gullet)
It is filled with specialized cells
It is divided into multiple chambers
It serves as both a digestive chamber and a hydrostatic skeleton (correct)

What is the primary function of the cnidocytes (stinging cells) found in the tentacles of Hydrozoa?

For filtering food particles
For locomotion
For capturing prey and defense (correct)
For reproduction

Which of the following is a characteristic of the medusa form in the Class Hydrozoa?

It has a complex stomodeum (gullet)
It is conspicuous and free-swimming
It is the dominant life stage (correct)
It has a divided coelenteron

How do Hydrozoa typically reproduce sexually?

Through separate sexes with external fertilization (D) Signup and view all the answers

What type of environment do Hydrozoa commonly inhabit?

Shallow saltwater habitats, including coastal areas, estuaries, and coral reefs (C) Signup and view all the answers

What is the primary food source for Hydrozoa?

Minute crustaceans, insect larvae, zooplankton, and other small organisms (D) Signup and view all the answers

What is the distinguishing feature of the medusa form of some jellyfish discussed in the text?

Flattened bell lacking typical swimming capability (D) Signup and view all the answers

What is the role of zooxanthellae in the symbiotic relationship with certain jellyfish?

Provide energy through photosynthesis (A) Signup and view all the answers

In the class Anthozoa, what is the function of cnidocytes on the hollow tentacles surrounding the central mouth?

Prey capture and defense (C) Signup and view all the answers

What aids in directing food particles into the gastrovascular cavity for digestion in Anthozoa?

Stomodeum leading from the mouth (A) Signup and view all the answers

How do polyps typically reproduce in Anthozoa?

Release gametes externally for fertilization (B) Signup and view all the answers

What is a characteristic of planula larvae in the life cycle of Anthozoa?

Settling onto a substrate after formation (D) Signup and view all the answers

What is a distinguishing feature of Physalia, a member of Class Hydrozoa?

Gas-filled float and cluster of polyps (C) Signup and view all the answers

Which structure in Physalia helps it achieve buoyancy in the water?

Pneumatophore (A) Signup and view all the answers

What is the role of Dactylozoids in Class Hydrozoa?

Long tentacles with venomous cnidocytes (C) Signup and view all the answers

How do Physalia colonies reproduce?

Through the production of gametes by Gonozoids (B) Signup and view all the answers

What is the primary function of Gonozoids in Class Hydrozoa?

Producing gametes (A) Signup and view all the answers

Which feature distinguishes Class Scyphozoa from Class Hydrozoa based on the text?

Free-swimming medusa dominant life cycle (D) Signup and view all the answers