How many of the following statement(s) is/are correct?
I. A prawn is an arthropod.
II. Flame cells are a part of the excretory system of an arthropod.
III. Fertilization is internal in Apis.
Prawn is an arthropod that has an organ system level of organization. They have green glands or malpighian tubules as excretory organs. Whereas the flame cells are excretory organs of Platyhelminthes.
The fertilization in arthropods is usually internal, i.e., the fusion of male and female gametes occurs inside the body. Apis (Honey bee) is an arthropod, and fertilization takes place within them (internal).