Botany - Biological Classification Question with Solution | TestHub

According to R. H. Whittaker, five-kingdom classification all unicellular eukaryotes are placed in kingdom Protista which is divided into five classes.
Red tide: Red dinoflagellates likeGonyaulax, multiply fast and give red colour to the sea . These also produce toxins in large amounts which results in death of fishes.

Diatoms and golden algae are placed in Chrysophytes. They are microscopic and floats passively in water current.