Question

For each phylum, list the characteristics;

3.) Platyhelminthes

Environment:

Level of organization (e.g. porifera = cellular):

Body symmetry:

Germ layers:

support system:

Nervous system:

Digestive system:

Circulatory system:

Respiratory system:

Excretory System:

Other Distinguishing Features:

4.) Mollusks

For each phylum, list the characteristics:

Environment:

Level of organization (e.g. porifera = cellular):

Body symmetry:

Germ layers:

support system:

Nervous system:

Digestive system:

Circulatory system:

Respiratory system:

Excretory System:

Other Distinguishing Features:

Answer 1

3) PLATYHELMINTHES CHARACTERISTICS:

- tissue-organ level of orginasation

-Bilateral symmetey.

-Triploblastic body. Third germ layer

-nervous system with large, interiorly situatedgangalia and nerve running aloung the body.

- digestive system branched and incomplete without anus.

-Circulatory system is wanting

- Excretory system includes lateral canals and protonephridia.Absent in some primitive forms.

-respiratory system are wanting.

- Better developed sensory organs.

- More complex and efficient gastrovascular cavity.

4) MOLLUSCA CHARACTERISTICS

- Tissue- system grade of body orginazation.

- bilaterally symmetrical.

- Triploblastic, coelomate, unsegmented.

- Nervous system of paired ganglia, connectives and nerves. Ganglia usually forms a circumentric ring.

- Digestivesystem complete with a gigestive gland or liver.

- Circulatory system is mainly of closed type.

- Respiration direct or by gillsor lungs or both.

- Excretion by apair of metanephradia.

- fertilization external.