Question

write a comparative account of arthropods and mollusca

Answer 1

Answer:

DIFFERENCE BETWEEN ARTHROPODA ND MOLLUSCA :-

ARTHROPODA :-

------------------------

1)Body is divided into head, thorax and abdomen.

2)Body is covered by chitinous exoskeletons.

3) They have jointed appendages.

4)Excretion occurs through coxal gland on malpighian tubules.

5) Respiration occurs through tracheae or book lungs, e.g. prawn, cockroach.

MOLLUSCA:-

-------------------

1)Soft body divided into three distinct parts- a distinct head, visceral mass and muscular foot.

2)Body is covered by calcareous shell.

3)They have distinct foot for moving around.

4)Excretions occurs through nephridia.

5) Respiration occurs through gills .

HOPE MY ANSWER WILL HELP U.

Explanation:

Answer 2

Molluscs and annelids are more closely related to each other than either is to arthropods. This means that segmentation as observed in arthropods and annelids is homoplastic and not homologous. In contrast, the trochophore larvae present in molluscs and annelids is probably a true homology.