Why is biodiversity important in ecosystems?

• A. To increase the amount of sunlight
• B. To slow down decomposition
• C. To make ecosystems more colorful
• D. To improve resilience, stability, and adaptability

Answer: (D)

Having a variety of species strengthens how an ecosystem handles change. When many species are present, multiple organisms can perform similar jobs—like decomposing matter, pollinating plants, or grazing on producers. If one species is stressed by drought, disease, or a new predator, others can take over its role, so essential processes keep happening. This redundancy helps the system resist disturbances, recover after them, and adjust to new conditions, which is what resilience, stability, and adaptability mean in ecosystems. Genetic diversity also helps populations adapt to pests, climate change, and disease over time, supporting long-term survival.

Options that focus on sunlight, slowing decomposition, or simply making things look more colorful don’t capture these core ecological benefits.