Bio Lab 7

Phylum Porifera

Sponges; simple multicellular animals with no true tissues or organs; filter feeders.

Phylum Cnidaria

Jellyfish, hydra, corals, and sea anemones; have true tissues, radial symmetry, and stinging cells.

Spicules

Hard skeletal structures made of silica or calcium carbonate that support and protect sponges.

Spongin

Flexible protein fibers that support the sponge.

Choanocyte

Collar cell that creates water currents and traps food particles.

Amoebocyte

Cell that digests food, transports nutrients, and produces spicules and spongin.

Spongocoel

Large central cavity inside a sponge where water flows.

Osculum

Large opening at the top of a sponge where water exits.

Gemmules

Survival structures that allow sponges to survive harsh conditions and grow into new sponges.

Filter Feeding

Process of removing tiny food particles from water as it flows through the body.

Water Flow Through a Sponge

Pores → Spongocoel → Osculum.

Radial Symmetry

Body parts arranged around a central point; allows organisms to sense their surroundings from all directions.

Mesoglea

Jelly-like layer between the outer and inner tissue layers of cnidarians.

Gastrovascular Cavity

Main digestive chamber with one opening; digests food and distributes nutrients.

Tentacles

Structures around the mouth used to capture prey and contain stinging cells.

Cnidocytes

Specialized stinging cells unique to cnidarians.

Nematocysts

Harpoon-like stingers inside cnidocytes used for defense and capturing prey.

Polyp

Attached, vase-shaped body form with the mouth facing upward.

Medusa

Free-swimming, bell-shaped body form with the mouth facing downward.

Class Hydrozoa

Includes hydra and Portuguese man-of-war; polyp stage is usually dominant.

Class Scyphozoa

True jellyfish; medusa stage is dominant.

Class Anthozoa

Includes corals and sea anemones; only the polyp stage is present.

Class Cubozoa

Box jellyfish; cube-shaped bell and very powerful venom.

Hydra

Phylum Cnidaria; Class Hydrozoa.

True Jellyfish

Phylum Cnidaria; Class Scyphozoa.

Sea Anemone

Phylum Cnidaria; Class Anthozoa.

Coral

Phylum Cnidaria; Class Anthozoa.

Box Jellyfish

Phylum Cnidaria; Class Cubozoa.

Sponges Symmetry

Usually asymmetrical.

Cnidarians Symmetry

Radial symmetry.

Sponges Have True Tissues?

No.

Cnidarians Have True Tissues?

Yes.

Function of Choanocytes

Create water currents and capture food.

Function of Amoebocytes

Digest food, transport nutrients, and build the sponge skeleton.

Function of Spicules

Support and protection.

Function of Nematocysts

Sting prey and provide defense.

Which Phylum Has Cnidocytes?

Cnidaria.

Which Organisms Are Filter Feeders?

Sponges (Phylum Porifera).

Which Class Includes Corals?

Anthozoa.

Which Class Includes Hydra?

Hydrozoa.

Which Class Includes True Jellyfish?

Scyphozoa.

Which Class Includes Box Jellyfish?

Cubozoa.