Question

A researcher wants to determine if a unicellular organism he discovered is an autotroph or a heterotroph. He radioactively labels the carbon in CO2 and C6H12O6, and exposes one culture of his organism to the labeled CO2 and another culture to the labeled C6H12O6. What would happen if his organism is an autotroph?A. Labeled carbon would be seen in the carbohydrates of organisms exposed to CO2. B. Labeled carbon would be seen in the carbohydrates of organisms exposed to C6H12O6. C. Labeled carbon would not be seen in the carbohydrates of either culture. D. Labeled carbon would be seen in carbohydrates of both cultures.

Answer 1

The correct answer is: A. Labeled carbon would be seen in the carbohydrates of organisms exposed to CO2.

Autotrophs organisms are capable to synthesize all necessary organic compounds from CO2 which is opposite from heterotrophs that are unable to do that and thus cannot produce their own food.

Autotrophs can produce complex organic compounds (carbohydrates, fats, and proteins) from simple substances present in its surroundings (e.g. CO2), generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis).