Question

1. the clusters of chlorophyll and proteins that absorb sunlight and generate high - energy electrons in the chloroplasts are called

a. carrier proteins.
b. transport chains.
c. photosystems.
d. synthase proteins.

1. in photosystem ii, as high - energy electrons are passed to the electron transport chain, the chlorophyll gains new electrons from

a. oxygen atoms.
b. water molecules.
c. hydrogen ions.
d. carbon dioxide.

Explanation:

• Question 11: Photosystems are the clusters of chlorophyll and proteins in chloroplasts that absorb sunlight and generate high - energy electrons. Carrier proteins are involved in transporting substances across membranes. Transport chains (like electron transport chains) are for passing electrons. Synthase proteins are for synthesis reactions (e.g., ATP synthase).
• Question 12: In photosystem II, when high - energy electrons are passed to the electron transport chain, water molecules (\(H_2O\)) are split. The oxygen from water is released as \(O_2\), and the electrons from water replace the electrons lost by chlorophyll. Oxygen atoms (\(O\)) are a product of water splitting (not a source of electrons for chlorophyll in this context). Hydrogen ions (\(H^+\)) are released from water splitting but do not directly give electrons to chlorophyll. Carbon dioxide (\(CO_2\)) is used in the Calvin cycle (light - independent reactions) and not as an electron source for chlorophyll in photosystem II.

Answer:

1. C. photosystems
2. B. water molecules