The question asks to identify the primary carbon dioxide acceptor in C₃ plants. This refers to the molecule that initially combines with CO₂ during the Calvin cycle (C₃ pathway) to start the carbon fixation process.
Correct Option: C) RuBP is a five-carbon sugar that acts as the primary CO₂ acceptor in C₃ plants, combining with CO₂ in a reaction catalyzed by RuBisCO.
The question asks to identify the photosystem responsible for water splitting during photosynthesis. This process, also known as photolysis, is crucial for providing electrons and protons for the light-dependent reactions.
B) Photosystem II is where water splitting (photolysis) occurs. This process is essential to provide electrons to PSII and release oxygen.
The question asks about the specific location of the enzyme RuBisCO within the chloroplast. To answer this, one needs to recall the different parts of a chloroplast and the primary functions associated with each part, particularly the stages of photosynthesis.
C) Stroma — The stroma is the fluid-filled space within the inner membrane of the chloroplast where the light-independent reactions (Calvin cycle) of photosynthesis take place. RuBisCO, the enzyme responsible for carbon fixation in the Calvin cycle, is abundant in the stroma.
The question asks to identify which substance is NOT a product of the light-dependent reactions of photosynthesis. To answer this, we need to recall the inputs and outputs of both the light-dependent and light-independent (Calvin cycle) reactions of photosynthesis.
B) Glucose — Glucose is synthesized during the light-independent reactions (Calvin cycle) using the ATP and NADPH produced during the light reactions, along with carbon dioxide. It is not directly produced by the light reactions themselves.
This question asks about the photosystems involved in cyclic photophosphorylation. Understanding the two main types of photophosphorylation (cyclic and non-cyclic) and the roles of Photosystem I (PS I) and Photosystem II (PS II) is key to answering this.
A) PS I — In cyclic photophosphorylation, electrons from PS I are excited by light, travel through an electron transport chain, and then return to PS I. This cyclic flow generates ATP without producing NADPH or releasing oxygen.
The question asks to identify the specific part of the chloroplast where chemiosmosis occurs during photosynthesis. Chemiosmosis is the process of ATP synthesis driven by a proton gradient, and in photosynthesis, this process is directly linked to the light-dependent reactions.
Correct Option: C) Thylakoid membrane — The thylakoid membrane is where the electron transport chain operates, pumping protons into the thylakoid lumen and creating the proton gradient necessary for chemiosmosis and ATP synthesis.