Class Trematoda: Infect the internal organs of hosts. Parasitic Can be endoparasites (live in the host) or ectoparasites (attach to external surfaces of the host. Size: ~ 1 cm to 10 cm Covered in an unciliated cuticle. Usually require 2 hosts to complete it's life cycle.
The difference between a mole and a wart is that moles are not contagious, but warts are. A mole, or nevus, is a collection of skin pigment cells. When they are small, they look like small brown dots. When the collection is larger, and slightly deeper, it can cause a raised skin colored bump over it.
Facts on Warts. Warts are small harmless tumors of the skin caused by a virus called the human papillomavirus. The appearance of warts can differ based on the type of wart and where it is located on the body. Most warts are well defined, with skin thickening.