NCERT Solutions for Class 11 Biology Chapter 11 Photosynthesis in Higher Plants
NCERT Solutions for Class 11 Biology Chapter 11 Photosynthesis in Higher Plants covers the site of photosynthesis, light and dark reactions, the C3 and C4 pathways, and factors affecting the rate of photosynthesis.
Overview of Topics & Subtopics (Click to Jump)
1. Site and Pigments of Photosynthesis
Short Note:
• Photosynthesis occurs mainly in the chloroplast; the light reactions occur in the thylakoid membranes (containing chlorophyll a, chlorophyll b, and carotenoids), and the dark reactions occur in the stroma.
2. Light Reaction
Short Note:
• Involves absorption of light, splitting of water (photolysis, releasing O2), and generation of ATP and NADPH through electron transport in Photosystem I and Photosystem II.
3. Dark Reaction (Calvin Cycle / C3 Pathway)
Short Note:
• Uses ATP and NADPH from the light reaction to fix CO2 and synthesise sugar; the first stable product is a 3-carbon compound (3-PGA), hence called the C3 pathway, occurring in the stroma.
4. C4 Pathway and Factors Affecting Photosynthesis
Short Note:
• The C4 pathway (Hatch-Slack pathway) is found in plants like maize and sugarcane, where the first stable product is a 4-carbon compound (oxaloacetic acid); more efficient in hot, dry conditions due to reduced photorespiration, using Kranz anatomy.
• Rate of photosynthesis is affected by factors including light intensity, CO2 concentration, temperature, and water availability (Blackman's Law of Limiting Factors).
NCERT Textbook Exercise Questions
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