Answer:
B cellular respiration and photosynthesis
Step-by-step explanation:
Photosynthesis and cellular respiration are both processes that are undergone by living cells.
In Biology, the law of conservation of energy states that energy can neither be created nor destroyed but only changed from one form to another i.e. transformation of energy.
Photosynthesis is a unique process carried out by the cells of plants and other autotophs in which they synthesize organic molecule (glucose) by combining carbondioxide (CO2) and water (H2O) in the presence of light from the sun. The process of photosynthesis transforms light energy from the sun to chemical energy stored in the bonds of the organic molecule produced.
Cellular respiration, on the other hand, is a process carried out by all living cells in order to obtain usable energy by the cell. Respiration breaks down food molecules to yield energy in form of ATP. The process of cellular respiration transforms chemical energy in food into heat energy released by cells after carrying out metabolic activities.
Hence, cellular respiration and photosynthesis are two activities carried out by living systems that illustrates the law of conservation of energy i.e. how uncreatable and undestroyable energy is transformed from one form to another.