Question

Flatworms Excretory system Digestive system ( Ho bay chin No body cavity latworms a Freelring s 2 Flukes Tapeworms Hooks and sucker Place the letter in the appropriate blank a. Cestoda b. Flame cells h. Platyhelminthes c. Scolex Tubellaria d. Incomplete j. Acoelomate e. Proglottids Parasitic f Incomplete 1 Schistosomiasis 8. Trematoda Tropical disease Ege production 10.

Answer 1

Answer can be seen as solved below in the diagram:

Excretory system s. Flame cells (6.) ) No body cavity (4. Acoelomate) 6. Incomplete (de) Digestive system flatworms - Platyhelminthe(n) Free living 2. Parasitic (k) (3. Tubellaria Flukes 8. Trematoda (g) Tapeworms (7. Cestoda (a) Tropical disease Lo Schistosomiasis Hooks and sucker g. scolex Egg production to. Proglottids (e)

Explanation with each fill in the blank highlighted according to the numbering:

1. Flatworms--> Platyhelminthes

Phylum Platyhelminthes is known to contain many worms which are also commonly known as flatworms. Therefore, all the worms in this phylum are given a common name as flatworms.

4.These worms lack a proper body cavity (coelom) therefore are called as acoleomates. This means that their body is solid between the outer covering surface and the digestive system, thus lacking a body cavity.

5. Excretory system of flatworms is made up of protonephridia which in turn is made up of flame cells which help in the excretion of waste.

6.Digestive system in flatworms is said to be incomplete because body has a single opening for entry and exit of the food from the gastrovascular cavity.

-Flatworms are mainly of two types in nature:

They can be either parasitic or free living.

Platyhelminthes is further divided into three classes, out of which Turbellaria include free-living worms and Trematoda and cestoda include parasitic worms.

3. Free living class is Turbellaria whose leading example is planaria (Dugesia).

In parasitic worms:

8. Class Trematoda includes digenetic flukes which are basically cylindrical or leaf like in shape with oral and ventral suckers (but no hooks ) present for the attachment to the body of their host. Leading examples of this class are liver fluke (Fasciola hepatica) and blood fluke (Schistosoma).

11. These parasitic worms belonging to the class trematoda are known to cause tropical diseases. One of which is schistosomiasis, which is caused by schistosomes.

It is a chronic illness which is known to affect many internal organs like intestine, liver, lung, spleen etc.

7. Class Cestoda contains parasitic tapeworms which are generally long and Ribbon like. Their each segment is called as proglottid.

9. Skolex is a structure present at the rear end of the tapeworms which basically contains hooks and suckers which are useful for the attachment of the worms to their hosts.

10. Tapeworms are hermaphrodite in nature. This is because each segment which is known as proglottid is known to contain both male and female sex organs. Therefore, after fertilization, the egg production takes place in each of the proglottid.