Protoplasmic Grade of Organisation :
It is found in the members of phylum Protozoa. Their body is unicellular and their all the vital activities are performed in the protoplasm with the help of various orgenelles. Hence, it is called as “protoplasmic grade of organisation”. The division of labor is found among the cell organelles.
Cellular Grade of Organisation :
The sponges (phylum-porifera) exhibit, cellular grade of organisation. Their body is multi cellular but the cells are not similar. They are differentiated to perform specific functions such as pinacoderm, choanoderm etc. Tissues and organs are absent. The cells exhibit division of labor. Hence, their body organization is called as cellular grade of organization.
