In the context of the given question:
1. Both carbon and water are components of all living things, making this statement true. Carbon is a key element in organic compounds like carbohydrates, lipids, proteins, and nucleic acids found in all living organisms. Water is essential for various biological processes and makes up a significant portion of living organisms.
2. Both carbon and water are not typically excreted by living things in their elemental forms. While some waste products may contain carbon or water molecules, these elements are usually recycled or reused within the organism rather than being excreted.
3. Both carbon and water must be ingested by living things. Organisms obtain carbon through the consumption of food sources containing organic compounds, while water is taken in through drinking or other means to maintain hydration and support physiological functions.
4. Both carbon and water are indeed primarily cycled by living things as part of biogeochemical cycles. For example, the carbon cycle involves processes such as photosynthesis, respiration, decomposition, and consumption that circulate carbon through the atmosphere, biosphere, geosphere, and hydrosphere.
Therefore, the statement "both are excreted by living things" is not true of carbon and water.
