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.
A. A wart is a harmless skin growth caused by some types of the virus called the human papillomavirus (HPV) . There are more than 100 known types of HPV. HPV infects the top layer of skin, usually entering the body in an area of broken skin. The virus causes the top layer of skin to grow rapidly, forming a wart.