Which element is essential to all living things, whether plant or animal?

Carbon is essential to all living things because it serves as the fundamental building block of organic molecules, which are vital for life. In both plants and animals, carbon atoms form the backbone of many structures including carbohydrates, proteins, lipids, and nucleic acids (DNA and RNA). This versatility allows carbon to create a vast variety of compounds necessary for metabolic processes, cellular structure, and energy storage.

All known life forms utilize carbon-based compounds, which is why it is often referred to as the "element of life." While other elements like oxygen, nitrogen, and hydrogen are also crucial for certain biological processes and structures, carbon's unique ability to form stable, complex molecules that can perform a myriad of functions is what makes it truly indispensable across different forms of life.