Which of the following organisms are unicelluar, which are multicelluar?

Question

1. coelastrum
2.daphnia
3.copepod

how do you know?

Answer 1

Coelastrum is unicellular.
Daphnia and copepods are multicellular.

Answer 2

Coelastrum is colonial, however all the cells making up the colony are identical, and each cell has all the requirements for life, and is therefore an individual unicellular organism. In Daphnia and Copepods there is differentiation of cell types, no cell being able to survive on its own, but each cell contributing to the life and health of the multicellular organism, and depending upon the other cells of the organism for its own life.
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