Biological systems are complex networks of living organisms and their interactions with each other and their environment. These systems can range from small-scale ecosystems, like a pond with fish and plants, to large-scale systems, such as the entire Earth with its diverse habitats. Each component, including animals, plants, and microorganisms, plays a vital role in maintaining balance and supporting life. In biological systems, processes like photosynthesis and nutrient cycling are essential for energy flow and sustainability. For example, plants convert sunlight into energy, which is then passed on to herbivores and carnivores in the food chain. Understanding these systems helps us appreciate the interconnectedness of life and the importance of preserving our natural world.