Question

Which one of the following is not an excretory organ?

• A. Flame cells
• B. Green glands
• C. Ommatidia
• D. Protonephridia

Answer 1

Answer:

C. Ommatidia

Ommatidia are the individual units that make up the compound eyes of arthropods, such as insects, crustaceans, and millipedes. Each ommatidium has a lens, a cluster of photoreceptor cells, and support and pigment cells. The outside of an ommatidium is covered by a transparent cornea.