Internal vs External Fertilisation
- Internal Fertilisation: Fertilisation occurs inside female body (Humans, Cows, Birds).
- External Fertilisation: Male and female gametes fuse outside in water (Frogs, Fish, Starfish).
- Metamorphosis: Drastic transformation of larva into adult during development: $\text{Egg} \rightarrow \text{Tadpole (Larva)} \rightarrow \text{Adult Frog}$.
