Chapter 5, Problem 1MCQ

Where does the energy come from to drive photosynthesis?

a. A chloroplast

b. ATP

c. The sun

d. Glucose

Summary Introduction

Introduction:

Photosynthesis is a process that takes place in green plants to construct complex organic compounds from water and carbon dioxide with the help of chlorophyll and sunlight. The whole process is completed in two steps; light reaction and dark reaction. ATP (adenosine triphosphate) production takes place in the light reaction of photosynthesis. This ATP is used to reduce ${\text{CO}}_{\text{2}}$ to form carbohydrate in the dark reaction.

Answer to Problem 1MCQ

Correct answer:

The energy to carry out photosynthesis comes from the Sun. Therefore, option c. is correct.

Explanation of Solution

Reason for the correct statement:

The sun provides the light energy that is trapped by the photosystems present in the chloroplast. They trap the solar energy and synthesize ATP from it. This ATP is further used to produce carbohydrates.

Option c. is given as “The sun”.

As, “Solar energy provides the energy to carry out photosynthesis”, is the right answer.

Hence, option c. is correct.

Reasons for the incorrect statements:

Option a. is given as “A chloroplast”.

Chloroplast is referred as the site of photosynthesis. It does not provide the energy to drive photosynthesis. So, it is a wrong answer.

Option b. is given as “ATP”.

ATP is the “energy currency” produced as a result of light reaction. So, it is a wrong answer.

Option d. is given as “Glucose”.

Glucose is the final product of photosynthesis. So, it is a wrong answer.

Hence, options a., b., and d. are incorrect.

Conclusion

Photosynthesis is the process, by which autotrophs produce food for themselves. They use solar energy for this purpose.