Biology STAAR (State of Texas Assessments of Academic Readiness) Practice Test

What type of organism is classified as an autotroph?

1. Fungi that decompose organic matter

2. Plants that produce their own food

3. Animals that consume other organisms

4. Bacteria that require oxygen

The correct answer is: Plants that produce their own food

Autotrophs are organisms that are capable of producing their own food using light or chemical energy. This ability is primarily seen in plants, which utilize photosynthesis to convert sunlight, water, and carbon dioxide into glucose and oxygen. Through this process, plants not only sustain themselves but also form the foundation of the food chain by providing energy to other organisms, including herbivores and the carnivores that eat them. In contrast, fungi are classified as decomposers, meaning they break down organic matter rather than producing their own food. Animals, including humans, are heterotrophs that rely on consuming other organisms for energy and nutrients. Bacteria that require oxygen may play important roles in various ecosystems, but they can be either autotrophic or heterotrophic, depending on their specific metabolic processes. Thus, the classification of autotrophs directly aligns with organisms like plants that generate their own sustenance.