Internal fertilization is when the egg/s is fertilized inside the mother. External fertilization is when the egg/s are fertilized outside of the mother.

The advantages of internal fertilization is more protection for the baby and a greater change of successful fertilization. Some advantages for external fertilization is larger number of off springs and easier to find mates.

The disadvantages for internal is limited amount of off springs and higher risk of STDs being passed. The disadvantages for external is environmental hazards and no guaranteed that sperm will come in contact with the eggs.

Internal and external fertilization