What are the advantages and disadvantages of external fertilisation?
The advantages in external fertilization is that there are lots of egg cells produce but the disadvantages are that a small number survive because if you are using a frog, the egg cells get eaten or don't get fertilized.
Internal reproduction: Advantages - - independent of external water medium (eg. ponds, streams etc.) - Prevent wastage of gametes and embryo - Greater chance of fertilisation - Embryo is nourished and protected Disadvantages - - Intermittent organ must be developed - Complicated behaviour must be evolved to bring the male and femal into intimate contact
There is a difference. Internal feritilisation takes place in the female's body while external fertilisation does not. External fertilisation usually requires a medium such as water, which the sperms can use to swim towards the egg cell. External fertilisation usually occur in fish and amphibians. Internal fertilisation occurs in mammals, insects, birds, reptiles.