Name: ______Date: ______Unit 7 Notes #3 - Phylum Platyhelminthes: Flatworms A) Body Plan: - All have ______

-______: Concentration of sensory organs and nervous tissue at the anterior end of the body (______).

-Well-developed ______layer called the ______between the ectoderm and endoderm. -Mesoderm includes: ______-Possess an ______: single opening (mouth/anus) to the gastrovascular cavity; use mouth to ingest food and use mouth to expel undigested wastes. B) Diversity: 1. Class ______: -______-Incomplete gut -No suckers or hooks -Ciliated epidermis Example: ______

2.Class ______: -______-Incomplete gut -______-Outer Cuticle (tegument) Example: ______

PLANARIA FLUKE

3. Class______: -______

-______-______and ______together form a ______for attachment to host -Body consists of repeating sections called ______

Example : ______C) ______Common To Most______Flatworms:

1) Parasitic flatworms often have suckers and hooks for attachments, form a structure called a ______.

2) ______(______) for protection so as

______or destroyed by the host. 3) Loss of digestive system in some (tapeworms) – these will ______

______nutrients through ectoderm. 4) Complicated life cycle with the production of many eggs and/or offspring and

______

D) Characteristics Of Common Platyhelminthes Members:

1. ______a. Digestion: Feed on small animals and the remains of larger dead animals.

-______/______is located mid-way along the ventral surface

(______) it acts to push food into the gastrovascular cavity.

-______are present in the pharynx and gastrovascular cavity (they secrete enzymes to digest food) -Gastrovascular cavity will also circulate nutrients and oxygen to various parts of the body. -Indigestible wastes are eliminated out of the mouth.

b. Nervous : -______

-A pair of ______run the length of a nervous system. -Connect to a pair of ______(a group of nerve cells) in the anterior end. -Show cephalization with a variety of sensory cells. -Sensory cells are sensitive to ______and various ______. c.______: -______are located below the ectoderm. -The outer layer of ______muscle that constrict the worm, making it ______and ______.

-Next layer uses ______muscles to ______the worm.

-There is also a third layer that runs ______(______) and makes the worm a little flatter.

d. Locomotion: -Body moves by co-ordinating its muscles and ______

______trail that it secretes from glands in the epidermis.

-______on the ventral epidermis assists in gliding.

2. ______

a. Digestion: -They are______.

-Mouth present in the middle of the

______

-The pharynx swallows the host’s tissues and bodily fluids (blood) into its

______b. Circulation and Respiration

-Gastrovascular cavity for circulation and respiration. -They live in tissues that are well supplied with nutrients and oxygen by the host’s blood. c. ______: - ______but they lack most of the special sensory cells found in Planaria.

d. ______: -Similar to planaria, ______on the ventral epidermis 3. ______a. Digestion: -Have______.

-Attach themselves to the lining of the host’s intestine by ______

______

Tapeworm’s Scolex

-Worm feeds by absorbing digested food. -Have a modified epidermis called a ______, this thicker skin prevents them from being digested. b) Circulation: -Receive oxygen from blood vessels in the host’s intestine.

-When oxygen is not available, ______

E) Reproduction In These Three Common Members of Platyhelminthes:

1. Planaria: -Reproduce ______-Missing parts will ______

-Can also reproduce ______

-______(contains both sexes in one individual), but requires reciprocal exchange of sperm and eggs between two individuals.

2.______: -Also hermaphrodites

-Complex life cycle with numerous larval stages that______

______

3. ______: - Constantly ______new body sections (______) posterior to its scolex. -Each proglottid contains both male and female reproductive organs. -Mature proglottids with ______

______-Often have larval stages that infect a number of different hosts Advances of the Platyhelminthes Over the Cnidaria

1. Platyhelminthes have their ______and even had some simple systems.

2) Unlike the previous two Phyla (Porifera and Cnidaria), the ______

______with the development of the middle layer (the mesoderm). The mesoderm has also provided for better muscle development and thus has resulted in an animal that moves around more efficiently.

3) As a result of moving around, platyhelminthes have further ______

______

4) Cnidarians had a nerve net for conducting impulses, but the Platyhelminthes have ______into two longitudinal nerve cords. (______).

LIVER FLUKE lifecycle