Question

why hydra has both types of digestion?

Answer 1

Cause food is stored in the gastrovascular cavity of hydra. Enzymes secreted by the hydra , it will down food from absorption. Hydra also use extracellular digestion and secrete molecules to break down the substrate they will grow. And intracellular digestion take place inside the cell. That's why hydra has two types of digestion.

Answer 2

Hydra is a cnidarians and has both extracellular and intracellular digestion. Though like porifera, the digestion is incomplete but hydra has a gastrovascular cavity which performs extracellular digestion. When a prey comes near to hydra, it traps it with the help of stinging cells present on tentacles and move inside the body to the cavity where enzymes break it down into smaller pieces and absorb it.

Hydra also performs intracellular digestion due to the absence of a true digestive system. Intracellular digestion of hydra takes place in the cytoplasm of a cell.