Question

Choose the odd members of pyrrophyta
A) Gonyaulax
B) Noctiluca
C) Gymnodinium
D) Physarum

Answer 1

Hint:Pyrrophyta is the division or category of algae. This division includes yellowish-green to golden-brown algae. These algae are mostly unicellular and dinoflagellates.

Complete answer:
The algae belonging to pyrrophyta are also called the fire algae.They have two different flagellars which are ribbon shaped.These algae contain several pigments like Chlorophyll A. Pyridine, Fucoxanthin, etc. and can photosynthesise.Pyrrophyta is also called the dinoflagellates.
>Gonyaulax – Gonyaulax is the genus of dinoflagellates. It belongs to the red dinoflagellates and commonly causes red tides. They are the aquatic organisms having two separate flagella. All the species of this genus are marine except one species that is Gonyaulax apiculata.
>Noctiluca – Noctiluca is a free living marine species of dinoflagellates. It is the sea sparkle. It is the non photosynthetic that means it is heterotrophic. They eat plankton, diatoms, other dinoflagellates, fish eggs and bacteria by the process of phagocytosis. The members of this genus can show bioluminescence (the process by which organisms emit light as a result of chemical reactions occurring in their body).
>Gymnodinium – Gymnodinium is a genus of dinoflagellates. It is a type of marine and freshwater plankton. It belongs to the red dinoflagellates that in concentration can cause red tides.
>Physarum – Physarum is the genus of mycetozoa slime moulds. It is a protest with diverse cellular forms and broad geographic distribution.
Therefore, it has been clear from the above discussion that Physarum is the odd member in the given options. All other members belong to the pyrrophyta.

Hence, option D is the correct answer.

Note:Dinoflagellates are the single celled eukaryotic organisms. Usually dinoflagellates constitute algae but they are mostly plankton. They can be found in marine as well as fresh water reservoirs. Dinoflagellates are the one of the largest group of marine eukaryotes.