Diatom (Kingdom Protista) Characteristics:

It is unicellular.

It has a nucleus.

 It is well organized.

It has all of the organelles.

It is photosynthetic, and divides through the mitosis process.

There is no formation of an embryo.

 Diatoms are a type of diatom that can be found in both marine and fresh water.

Spirogyra (Kingdom Plant) Characteristics:

Photosynthetic multicellular plants of eukaryotic cells with real nuclei and membrane bound organelles.

Mitosis and meiosis are two types of cell division.

Algae are marine organisms that reproduce sexually by conjugation.

In the cell, large ribbon-shaped chloroplast are spirally arranged.

Spirogyra has a filamentous shell.

Filament is made up of a single row of tubular cells that are fused together end to end.