Question

Penetration power is maximum of violet light. $B-phycoerythrin$ is only pigment to absorb violet light. Due to phycoerythrin, red algae is deepest algae.

Answer 1

Red algae are usually present at the bottom or base of the oceans, they have pigments like phycoerythrins and phycobilins. These pigments absorb those lights that are penetrated deeper into the oceans such as violet light or blue light as they have a shorter wavelength. The light having longer wavelengths can be absorbed by the organisms that are present at the deeper region of the sea. These light have a high penetrating power than the ones like red light which have a shorter wavelength.