Biology · STRUCTURAL ORGANISATION IN ANIMALS

Which combination of characteristics distinguishes a male frog from a female frog externally?

1. Presence of five digits on the forelimbs and webbed feet on the hindlimbs.
2. Presence of sound-producing vocal sacs and a copulatory pad on the first digit of the forelimbs.
3. Absence of vocal sacs and presence of copulatory pads on all digits of the hindlimbs.
4. Presence of a copulatory pad on the fourth digit of the hindlimbs and brighter dorsal coloration.