All organisms contain _ and require it to survive A. Helium B. Carbon C. Zinc D. Polonium
The Correct Answer and Explanation is:
Correct Answer: B. Carbon
Explanation
All living organisms contain carbon, and it is absolutely essential for life as we know it. Carbon is the backbone of all organic molecules, which are the fundamental building blocks of life. These include carbohydrates, lipids (fats), proteins, and nucleic acids (DNA and RNA). What makes carbon unique is its ability to form stable covalent bonds with many elements, including itself. This bonding ability allows carbon to form long chains, complex rings, and three-dimensional structures necessary for life’s complexity and diversity.
In biological systems, carbon plays a key role in metabolism, energy storage, and cellular structure. For instance, glucose (C₆H₁₂O₆) is a carbon-based sugar that provides energy to cells through cellular respiration. Proteins, which are essential for enzymes and structural functions, are composed of amino acids—organic compounds built around carbon atoms. DNA and RNA, the molecules responsible for genetic information, have carbon-rich sugar backbones.
Carbon also exists in the atmosphere as carbon dioxide (CO₂). Through the process of photosynthesis, plants convert CO₂ and sunlight into glucose and oxygen, supporting not only their own growth but also providing food and oxygen for animals and humans. In turn, organisms release carbon back into the atmosphere through respiration and decomposition, maintaining the carbon cycle, which is vital for Earth’s ecosystems.
The other elements listed—helium, zinc, and polonium—are not universally required for life. Helium is an inert gas with no biological role. Zinc is a trace mineral important for enzymes and immune function, but not all life forms need it. Polonium is a highly radioactive element and is toxic to living organisms.
Thus, carbon is the fundamental element shared by all known forms of life, making it essential and irreplaceable in biological systems.
