Chapter 6, Problem 1SQ

A cat eats a bird, which ate a caterpillar that chewed on a weed. Which organisms are autotrophs? Which ones are heterotrophs?

Summary Introduction

To determine: The autotrophic and heterotrophic organisms.

Concept introduction:

According to energy consumption pathway, organisms are split up into autotrophs and heterotrophs. Autotrophs are organisms that convert simple substances from the environment into complex organic compounds by using light energy in the process of photosynthesis. Heterotrophs are organisms that cannot synthesize their own food; they imbibe or obtain their food and energy from plant or animal sources.

Explanation of Solution

Autotrophic organisms usually plants biosynthesize their own food by photosynthesis. A weed also prepares its own food by photosynthesis. Hence, a weed is an autotroph.

A cat eats a bird; bird eats a caterpillar; and a caterpillar eats weed. Since these organisms are unable to synthesize their own food, they are heterotrophic organisms.