Living things contain four major types of carbon-based molecules. The organic molecules in living things fall into four major groups— carbohydrates, lipids, proteins, and nucleic acids. You may already be familiar with these types of molecules and their functions.
Living things four major types of carbon-based molecules. The organic molecules in living things fall Into four major groups- carbohydrates, lipids, proteins and nucleic acids.
Answer: The Pulmonary vein blood vessel carries oxygenated blood from the lungs back to the heart. Therefore, it carries the highest concentration of oxygen.
Explanation: i think is the answer not sure hope it help this question :)
Internal and external regulators are two types of proteins that regulate the cell cycle. Internal regulators allow the cell cycle to proceed only after certain events occur. External regulators speed up or slow down the cell cycle.
