Question

classify aschelminthes upto class level​

Answer 1

Answer:

.

Explanation:

Answer 2

Explanation:

1. Habitat:

Many roundworms live as parasites in plants and animals. They cause serious agricultural, veterinary and human health problems. Round worms are also free living and occur in fresh water, sea water and soil.

2. Body Form:

They are called round worms because they appear circular in cross section. They are un-segmented.

3. Body wall:

It consists of firm, non living resistant cuticle, syncytial epidermis (a continuous layer of cytoplasm with scattered nuclei) and muscle layer.

4. Body cavity:

The body cavity is called pseudocoel or pseudocoelom as it devel­ops from the blastocoel of the embryo. Pseudocoel is filled with pseudocoelomic fluid.

5. Digestive Tract:

Alimentary canal is complete with muscular pharynx.

6. Skeletal, respiratory and circulatory systems are absent:

Pseudocoelomic fluid present in the pseudocoelom maintains body shape and forms hydro skeleton. Gas­eous exchange in aerobic respiration occurs by diffusion through the body surface. The pseudocoelomic fluid transports materials.

7. Excretory System:

The excretory system consists of gland cells, or of canals or of both. In Ascaris, ‘H’ shaped excretory system of canals and complicated “giant cell” called “renette cell” is present. Ammonia is main excretory matter. However, Ascaris also excretes urea.

8. Nervous System:

It consists of a circumpharyngeal ring that gives rise to nerves forwards as well backwards.

9. Sense Organs: