What is an auxotroph?

Bending of plants towards the sun is called positive phototropism. Auxotrophs are the mutant cells that are incapable of utilizing certain nutrients or synthesizing certain compounds and hence they can grow on minimal media plus the specific growth supplement for which they are mutant. An organism that depends on another living organism for its nutritional requirement is heterotrophic; it can be a primary, secondary or tertiary consumer depending on its position in the food chain. Plants are chlorophyll-containing autotrophic organisms that can fix atmospheric carbon dioxide into carbohydrates in the presence of sunlight and water. The correct answer is B.