The Fascinating World of Cnidarians

What phylum of marine organisms includes corals, anemones, hydroids, and jellyfish?

• Cnidarians

• Arthropods

• Mollusks

• Echinoderms

What type of body symmetry is characteristic of Cnidarians?

• Bilateral

• Radial

• Asymmetrical

• Spherical

What are the two basic body forms found in Cnidarians?

• Larva and Adult

• Male and Female

• Polyp and Medusa

• Sessile and Motile

Which of the following is a distinguishing feature of a polyp body form?

• Umbrella-shaped and free-moving

• Bell-shaped and planktonic

• Tube-shaped with tentacles around the mouth

• Colonial and gas-filled

What is the process called when a Moon Jellyfish polyp undergoes asexual reproduction by dividing its body into segments?

• Budding

• Fragmentation

• Strobilation

• Binary fission

What characteristic describes many planktonic jellyfish?

• They are fast and active swimmers

• They actively hunt their prey

• They rely on ocean currents for movement

• They are sessile and attached to the seabed

What is the primary function of nematocysts in jellyfish?

• Photosynthesis

• Reproduction

• Stinging for defense and prey capture

• Locomotion

What is the primary function of the long tentacles of a Portuguese Man o' War?

• To provide buoyancy for the organism.

• To capture and kill prey using stinging cells.

• To aid in reproduction by releasing gametes.

• To filter feed on microscopic plankton.

What specialized structures are responsible for digesting prey in a Portuguese Man o' War?

• Nematocysts

• Pneumatophores

• Gastrozooids

• Gonophores

Which statement best describes the biological structure of siphonophores?

• They are single, large, multicellular organisms.

• They are colonies made up of specialized individual zooids.

• They are a type of free-swimming jellyfish.

• They are sedentary organisms that attach to the seafloor.