External fertilisation takes place in:

The correct answer is Option (2) → Frog

In external fertilisation, syngamy takes place outside the body, in water. Frogs release eggs and sperms into water.

Option (2) Frog — Correct. In most aquatic organisms such as many algae, fishes and amphibians, syngamy occurs in the external medium (water), outside the body. The frog is an amphibian, so it shows external fertilisation.

Note: This question is from Chapter 1, Reproduction in Organisms, of the pre-rationalised NCERT book. This chapter is not in the present NCERT book (2026-27). The extract below is from the pre-rationalised edition.

NCERT Extract (Pre-rationalised edition, Chapter 1, Reproduction in Organisms):
Fertilisation – “… In most aquatic organisms, such as a majority of algae and fishes as well as amphibians, syngamy occurs in the external medium (water), i.e., outside the body of the organism. This type of gametic fusion is called external fertilisation. Organisms exhibiting external fertilisation show great synchrony between the sexes and release a large number of gametes into the surrounding medium (water) in order to enhance the chances of syngamy. This happens in the bony fishes and frogs where a large number of offspring are produced.”