Syngamy is the process of fusion of gametes. Amphibians show external fertilisation, where they release their gametes outside their body in water. Thus, syngamy occurs in water, outside the body. Reptiles on the other hand, show internal fertilisation i.e., the male copulates with female to release his gametes into the female's body. Inside female's body, the two gametes fuse i.e., syngamy occurs.