AP BIOLOGY

Detailed explanation-1: -Protists are mostly unicellular (one-celled) eukaryotes. A few protists are multicellular (many-celled) and surprisingly large. For example, kelp is a multicellular protist that can grow to be over 100-meters long (Figure below).

Detailed explanation-2: -Although most protists are single-celled, protists like kelp (brown algae) can grow over 100 meters. Therefore, not all protists are unicellular.

Detailed explanation-3: -Most protists are microscopic and unicellular, but some true multicellular forms exist. A few protists live as colonies that behave in some ways as a group of free-living cells and in other ways as a multicellular organism.

Detailed explanation-4: -A Protist is a unicellular, eukaryotic organism. This means that they are made up of one cell and that cell contains a membrane bound nucleus with other specialized organelles.