protozoan

As nouns the difference between protozoan and rhizomania

is that protozoan is (cytology) any of the diverse group of eukaryotes, of the phylum protozoa, that are primarily unicellular, existing singly or aggregating into colonies, are usually nonphotosynthetic, and are often classified further into phyla according to their capacity for and means of motility, as by pseudopods, flagella, or cilia while rhizomania is an abnormal development in the taproots of some plants, especially sugar beet, characterized by fine, hairy secondary roots; it is caused by the infection of the plant with a virus transmitted by a protozoan.

As an adjective protozoan

is of, pertaining to, or characteristic of a protozoan.