Question

Which of the following is the ultimate source of energy for all living organisms?

• A. Water
• B. Sun
• C. Food
• D. Tea

Answer 1

Answer: (B)

Sun

Photosynthesis is a process used by plants and other organisms to convert light energy, into chemical energy. It takes place by two steps light reaction and dark reaction. Light reaction synthesizes ATP and NADPH${}_2$ which is utilized for fixation of carbon dioxide into carbohydrates during the dark reaction. So, the sun is called as the ultimate source of energy for all living organisms.

So, the correct answer is option B.