Question

Fertilisation that occurs outside the organisms, in an external medium is called

• A. internal fertilisation
• B. external fertilisation
• C. syngamy
• D. fusion

Answer 1

The correct option is B external fertilisation

If the fertilisation occurs outside the organisms, in an external medium, it is called external fertilization.
Here, one or several females release their eggs and one or several males release sperm in the same area, at the same time.
The male as well as female gametes are produced in large numbers in order to enhance the chances of fertilisation. As a result a large number of offsprings can be produced.
E.g: fish, crustaceans, mollusks, echinoderms, etc.