UNIT 5 Notes #3 - Phylum Cnidarian

Name: ______Date: ______UNIT 5 Notes #3 - Phylum Cnidarian

A) Examples of Cnidarians

1.______

-______

-Spend ______-No medusa stage, other hydrazoans have a very short medusa stage.

2. ______

-Class ______-Jellyfish go through the same life-cycle stages as hydrozoans

-In Scyphozoans the ______

______- The ______of most jellyfish are harmless to humans, but a few can cause painful stings.

3. ______

-Class ______

Anthozoans have ______in their life cycle.

B) Cnidarian______:

Body Plan: - ______body with a single opening.

- Opening will allow ______- Surrounding the mouth is a ring of tentacles (usually contains stinging cells)

- ______contain nematocysts; when touched, the ______

______, paralyzing or trapping it. - Separating the outer ectoderm from the inner endoderm is a layer of mesoglea. (Mesoglea offers support for the animal).

-The body has ______. a) ______– Usually attached to some object with the______

______.

- ______(non-motile stuck to the bottom) b) ______– ______

______

- Locomotion is achieved by individual ______cells all working together to change shape. - Nematocysts fire on contact, after paralyzing its prey,______

______. C) Various Body Systems: 1) DIGESTION: Food is ______

______in order to digest food. Other cells of the ______will then absorb the digested nutrients. Indigestible material will then ______

______

2) CIRCULATION: ______. Food/nutrient particles will be passed through the central cavity by body movements and by flagellated cells in the endoderm. Thus the cavity is involved in both ______

3) ______and______:

-Both take place by ______that bathes the tissues.

4)NERVOUS: There is a limited amount of nervous and sensory tissue. This ______is used for co-ordination. Sensory cells are sensitive to touch and various chemicals.

5) MUSCULAR: ______

______

6) REPRODUCTION:

______- Many______, this may form new polyps or medusae.

______- ______reproduces sexually. ______

______which travel through the water to the ______which has produced eggs.

- The fertilized eggs are released out of the mouth to develop into______

______, this stage will usually develop into a polyp.

- Some Cnidarians (ex hydra, sea anemone) have polyps that can also reproduce sexually.

D) Advantages of Motile and Non-Motile Stages/Forms In Life Cycle: a) If motile,______; if non-motile you stay

______b) Advantage of being sessile (______) is that they ______

______c) Disadvantage of being motile is that you can easily get carried away by the water currents.

E) ______of Cnidarians:

- ______with other animals.

- ______for many marine animals. They contain tunnels, caves, and deep channels in which animals live. Coral reefs

______and for animals that produce valuable shells, pearls, and jewelry.

-Protect land from erosion by______. If destroyed, large amounts of shoreline maybe washed away.

-______by many Cnidarians.

- ______- ______