You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the 9 + 2 filament pattern. It has well-developed organelles and two nuclei, one large and one small. This organism is most likely to be a ________.
A) foraminiferan
B) radiolarian
C) ciliate
D) kinetoplastid

Question

Quizplus · Accepted Answer

The description of the organism matches that of a ciliate, which are unicellular and heterotrophic, use short extensions of the cytoplasm for motility with the 9 + 2 filament pattern, have well-developed organelles, and often have two nuclei, a larger macronucleus and a smaller micronucleus. Foraminiferans and radiolarians are also unicellular protists, but they are typically marine, have shells or tests made of calcium carbonate or silica respectively, and lack the 9 + 2 flagella pattern. Kinetoplastids are also unicellular heterotrophs but have unique features such as a kinetoplast and a single large mitochondrion.

You Are Given an Unknown Organism to Identify