Question

9.water, sugar, and other important nutrients need to be transported from one part of the plant to another.

• explain how plants transport water from the roots.
• how is water used in photosynthesis?

read the question carefully. then enter your answers in the box provided.

Explanation:

• Transpiration and Xylem Function:

Plants transport water from roots to other parts through transpiration - pull. Water evaporates from leaves (transpiration), creating a negative pressure. Xylem vessels, which are long, hollow, dead cells with lignified walls, conduct water. The cohesive (water - water) and adhesive (water - xylem wall) properties of water help in maintaining a continuous column of water in xylem, allowing water to move upwards against gravity.

• Role of Water in Photosynthesis:

In the light - dependent reactions of photosynthesis, water is split (photolysis). The chemical equation for photolysis is \(2H_{2}O
ightarrow4H^{+}+O_{2}+4e^{-}\). The electrons (\(e^{-}\)) are used to replace those lost by chlorophyll in photosystem II, protons (\(H^{+}\)) contribute to the proton gradient for ATP synthesis, and oxygen (\(O_{2}\)) is released as a by - product.

Answer:

• Transport of water from roots: Water is transported from the roots to other parts of the plant through the xylem. Transpiration (evaporation of water from leaves) creates a tension (negative pressure). The cohesive property of water (water molecules stick to each other) and adhesive property (water molecules stick to the xylem cell walls) allow water to form a continuous column and move upwards in the xylem vessels.
• Use of water in photosynthesis: In photosynthesis, water is used in the light - dependent reactions. Water is split (photolysis) into hydrogen ions (\(H^{+}\)), electrons (\(e^{-}\)), and oxygen (\(O_{2}\)). The electrons are used to replenish the electrons lost by chlorophyll in photosystem II, the \(H^{+}\) ions contribute to the proton gradient for ATP synthesis, and oxygen is released as a by - product.