Q. Which of the following is not unicellular?
Answer: Hydra
Notes: Unicellular organism is an organism which only has one cell while a multicellular organism is an organism that made up of more than one cell. Organisms such as amoeba, plasmodium, paramecium are unicellular organisms. Hydra (animal) and spirogyra (plant) are examples of multicellular organism.

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app. Question Number: 90 in 3. Classification of Organisms in above course in App.