that they dont have to touch each other like with with mammals
this is poo if it can t answer this question
There has not been any huge advantage but they can produce a number of the eggs.
external
The 2 fertilisation's are external fertilisation, or internal fertilisation. External fertilisation is the type frogs do.
A toad goes through external fertilisation/fertilization
internal
what two classes of vertebrates use external fertilisation
Yes
internal is in and external is out fertilisation
Because - external fertilisation is 'left to chance'. There's no guarantee that every egg laid will be fertilised by sperm. Internal fertilisation is much more successful.
arthropods usually have external fertilization
spiders