Phylum Cnidaria

Front

What is the defining characteristic of the phylum Cnidaria?

Back

Cnidarians are characterized by the presence of cnidocytes, specialized cells that contain nematocysts for capturing prey.

Front

What are the two main body forms of cnidarians?

Back

The two main body forms of cnidarians are the polyp and the medusa.

Front

What is a polyp?

Back

A polyp is a cylindrical, sessile body form of cnidarians that is typically attached to a substrate.

Front

What is a medusa?

Back

A medusa is a free-swimming, umbrella-shaped body form of cnidarians, such as jellyfish.

Front

What is the function of nematocysts?

Back

Nematocysts are organelles within cnidocytes that eject a filament to inject venom into prey.

Front

What triggers the nematocyst to fire?

Back

The nematocyst fires when prey touches the trigger, a sensitive structure on the cnidocyte.

Front

What is the significance of Turritopsis dohrnii in the study of cnidarians?

Back

Turritopsis dohrnii is known as the 'immortal jellyfish' because it can revert to its polyp stage after maturing.

Front

What does it mean for a cnidarian to be motile?

Back

Being motile means that the cnidarian is capable of movement, as seen in the medusa form.

Front

What are the ecological roles of cnidarians?

Back

Cnidarians play important roles in marine ecosystems as predators, prey, and contributors to coral reef structures.

Front

How do cnidarians reproduce?

Back

Cnidarians can reproduce both sexually and asexually, with some species capable of budding.