Final answer:
The food that organisms eat mainly comes from plants, which use photosynthesis to convert solar energy into chemical energy, starting the food chain. Herbivores consume these plants, carnivores eat the herbivores, and decomposers break down dead material, cycling nutrients back into the soil. so, option D is the correct answer.
Step-by-step explanation:
Most of the food that organisms eat can be traced back to plants. Plants use photosynthesis to capture sunlight, converting solar energy into chemical energy in the form of glucose. This process forms the basis of the food chain, as herbivores eat the plants to obtain energy, and then carnivores eat the herbivores. Additionally, decomposers, including many types of bacteria and fungi, break down dead plant and animal material, releasing nutrients back into the soil, which plants can then use to grow and continue the cycle.
Answering the review question, bacteria that feed upon decaying organic matter in the soil would best be described as decomposers. These decomposers are essential for maintaining the nutrient cycles, as they break down organic matter into nutrient compounds necessary for plant growth. Thus, they contribute significantly to the health of ecosystems and the plants within them. Most of the food that organisms eat can be traced back to plants. Plants benefit from an endless supply of carbon; soils benefit from being naturally fertilized; and bacteria benefit from using photosynthates from plants.