Chapter 20, Problem 19STP

Summary Introduction

To determine:

Carotenoid is a better pigment for algae which are present below the surface.

Introduction:

Algae are the microscopic autotrophs found in the water. They are photosynthetic and are the primary source of nutrients for small fishes.

Explanation of Solution

The water refracts and reflects the light, which makes it not possible for the red light to penetrate below the surface. Chlorophyll is a pigment that traps the blue and red-light wavelength for using it as a source of energy for photosynthesis. In case, the red light is not able to penetrate below the surface, the organism present beyond it cannot perform photosynthesis properly. So, in tis cae chlorophyll becomes insufficient.

However, carotenoids are the pigments that absorb green light. This green light can easily penetrate the surface of water and can be available for the algae to use as light energy. So, if algae which survive below the surface have carotenoid pigments in their system, can easily trap light energy for photosynthesis.