Question

Biologists sometimes divide living organisms into two groups: autotrophs and heterotrophs. How

do these two groups differ?

A) They use different sources of carbon.
B) They use different electron acceptors.
C) They differ in the way they generate ATP.
D) They use different sources of energy.

Answer 1

D

Step-by-step explanation:

Autotrophs produce their own food using energy from sunlight or inorganic compounds, while heterotrophs obtain energy by consuming other organisms.

Answer 2

Autotrophs synthesize their own food from inorganic substances (CO₂), and can be photoautotrophs (using sunlight) or chemoautotrophs (using inorganic molecules). Heterotrophs obtain both energy and carbon by consuming other organisms, relying on autotrophs and other heterotrophs for nutrients. The key difference between them is their source of carbon and energy.

Step-by-step explanation:

Autotrophs and heterotrophs differ primarily in their sources of carbon and energy. Autotrophs are organisms that can synthesize their own food from inorganic substances like carbon dioxide (CO₂), making them independent producers within ecosystems. They are broadly categorized into photosynthetic autotrophs (photoautotrophs) that use sunlight as an energy source, like plants and certain bacteria, and chemosynthetic autotrophs (chemoautotrophs) that rely on inorganic molecules for energy.

In contrast, heterotrophs, like humans and other animals, depend on organic substances for both energy and carbon; they consume other organisms to meet their metabolic needs. This makes them consumers in an ecosystem, reliant on autotrophs and other heterotrophs for nutrients. Therefore, the main difference lies in their carbon source, with autotrophs obtaining carbon from inorganic compounds and heterotrophs acquiring carbon from organic compounds, and their fundamental energy sources.