Biology · STRUCTURAL ORGANISATION IN ANIMALS

Regarding the integumentary adaptations of Rana tigrina, which of the following mechanisms explains how water is acquired by the body?

1. Active drinking through the buccal cavity followed by rapid absorption in the stomach.
2. Intake via the cloacal aperture by reverse peristalsis during aquatic diving.
3. The frog never drinks water; instead, water is absorbed directly through the moist, mucus-coated skin.
4. Filtration of water exclusively through specialized nephric pores located along the ventral fold.