Sponges and Cnidarians

What is an animal?

Animals are heterotrophic, eukaryotic, multicellular, and lack cell walls.

What percentage of all animals have backbones?

Roughly 3-5% of all animals have backbones.

What are aquatic animals that strain floating plants and animals from the water they take in called?

Filter feeders.

What are the seven essential functions all animals must perform to survive?

Feeding, Respiration, Circulation, Excretion, Response, Movement, Reproduction.

What terms are associated with the body plan of sponges?

Sponge skeletons are supported by spiny spicules or a network of flexible protein fibers called spongin.

How do sponges reproduce sexually?

By a process called spawning.

What essential function describes why a sponge releases toxins when threatened?

Response, because a sponge responds to stimuli.

Why are flagella important to sponges?

They create water currents to bring new food closer for filter feeding.

How do sponges benefit some marine animals?

They form mutualistic benefits or provide a home for other organisms.

What symbiotic relationships do sponges form?

Mutualistic relationships with organisms like bacteria, algae, and protists.

What are cnidocytes?

Specialized stinging cells that eject poisonous fluid.

Which animals are the simplest to have body symmetry?

Cnidarians.

What two functions do nematocysts perform?

Prey capture and defense.

What are three characteristics of cnidarians?

Soft-bodied, carnivorous, with stinging tentacles and body symmetry.

What are the two basic body types of cnidarians?

Polyp and Medusa.

What type of body symmetry do cnidarians exhibit?

Radial symmetry.

How do polyps differ from medusas?

Polyps have upward-facing mouths and do not move, while medusas have downward-facing mouths and can move.

What do the specialized nerve cells of cnidarians make up?

A nerve net.

How does the medusa stage of jellyfish reproduce?

Sexually.

What is the function of a cnidarian’s gastrovascular cavity?

Digestion.

What class of cnidarians does the Portuguese man-of-war belong to?

A floating colony of polyps.

What three factors are necessary for coral reefs?

Temperature, water depth, and light intensity.

Why can many cnidarians only live in bright light?

They depend on algae that require sunlight for photosynthesis.

What does coral reef 'bleaching' mean?

Coral loses color due to disturbances affecting its mutualistic algae, leading to increased mortality.

What are three causes of coral reef 'bleaching'?

Change in ocean temperature, runoff and pollution, and overexposure to sunlight.