Name one biotic factor that affects an ecosystem.

A biotic factor refers to any living component that influences an ecosystem's structure and function. The correct answer highlights plants, animals, fungi, and bacteria, all of which play significant roles in ecosystems. Plants, for instance, are primary producers that convert sunlight into energy through photosynthesis, forming the base of most food chains. Animals can be herbivores, carnivores, or omnivores, participating in the transfer of energy within food webs. Fungi and bacteria are essential decomposers that break down organic matter, recycling nutrients back into the ecosystem.

In contrast, the other options represent abiotic factors, which are non-living elements that also affect ecosystems. Water and soil minerals, while essential for plant growth and overall ecosystem health, are not living components. Sunlight, similarly, is a crucial energy source, but it is not a biotic factor as it does not consist of living organisms. Understanding the distinction between biotic and abiotic factors is fundamental in studying ecosystem dynamics.