Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Which substance enters through plant roots and is essential for photosynthesis?
A
Glucose ($C_6H_{12}O_6$)
B
Oxygen ($O_2$)
C
Carbon dioxide ($CO_2$)
D
Water ($H_2O$)
Verified step by step guidance
1
Step 1: Understand the process of photosynthesis. Photosynthesis is the process by which plants convert light energy into chemical energy stored in glucose ($C_6H_{12}O_6$). This process requires water ($H_2O$), carbon dioxide ($CO_2$), and sunlight.
Step 2: Identify the role of water ($H_2O$) in photosynthesis. Water is absorbed through the roots of the plant and transported to the leaves via the xylem. It serves as a source of electrons and hydrogen ions during the light-dependent reactions of photosynthesis.
Step 3: Recall the light-dependent reactions. In these reactions, water molecules are split into oxygen ($O_2$), protons ($H^+$), and electrons through a process called photolysis, which occurs in the thylakoid membranes of chloroplasts.
Step 4: Eliminate the incorrect options. Glucose ($C_6H_{12}O_6$) is a product of photosynthesis, not a reactant. Oxygen ($O_2$) is released as a byproduct during the light-dependent reactions. Carbon dioxide ($CO_2$) is absorbed through the stomata in leaves, not through the roots.
Step 5: Conclude that water ($H_2O$) is the correct answer. It enters through the roots and is essential for photosynthesis, specifically in the light-dependent reactions where it is split to provide necessary components for the process.