Question

which statement best describes the relationship between carbon - based molecules and living organisms?
only plant cells use energy from carbon - based molecules
carbon - based molecules are only found in animals
all animal and plant cells use energy that comes from carbon - based molecules
carbon - based molecules are only used for structural support in organisms

Explanation:

• Option 1: Both plant and animal cells use energy from carbon - based molecules. Plants use cellular respiration (which involves carbon - based molecules like glucose) to release energy, so this option is incorrect.
• Option 2: Carbon - based molecules are found in all living organisms (plants, animals, fungi, bacteria, etc.), not just animals. So this option is incorrect.
• Option 3: All animal and plant cells use energy from carbon - based molecules. For example, in cellular respiration, glucose (a carbon - based molecule) is broken down to release ATP (energy currency of the cell). This option is correct.
• Option 4: Carbon - based molecules are not only used for structural support. They are also used for energy storage (e.g., glucose, glycogen, starch) and as sources of energy (through processes like cellular respiration). So this option is incorrect.

Answer:

All animal and plant cells use energy that comes from carbon - based molecules.