🌿 Photosynthesis in Higher Plants – NEET Summary & Practice

-

🌞 Introduction

Photosynthesis is the biochemical process by which green plants convert solar energy into chemical energy. Understanding this chapter is crucial for NEET 2025, as it involves key concepts like light reactions, C3 and C4 cycles, and photorespiration.


---

🌱 Key Concepts at a Glance

📌 1. Photosynthesis Equation

6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂

📌 2. Site of Photosynthesis

Occurs in chloroplasts

Thylakoids: Light reactions

Stroma: Dark reactions


📌 3. Pigments

Chlorophyll a (main pigment)

Accessory pigments: chlorophyll b, carotenoids, xanthophylls



---

⚡ Light Reaction (Photochemical Phase)

Occurs in thylakoid membranes

Involves photolysis of water, ATP synthesis, and NADPH formation

Includes Photosystem I (PSI) and Photosystem II (PSII)


Major steps:

Non-cyclic photophosphorylation – both PSI & PSII involved

Cyclic photophosphorylation – only PSI used; no O₂ or NADPH formed



---

🧪 Dark Reaction (Biosynthetic Phase)

Calvin Cycle (C₃ pathway)

First stable product: 3-PGA

Enzyme: RuBisCO


C₄ Cycle

First stable product: Oxaloacetic acid (OAA)

More efficient in high temperature




---

🌬️ Photorespiration

Wasteful pathway

Involves oxygenation of RuBP

Occurs in C₃ plants

Not seen in C₄ plants due to spatial separation of Calvin cycle and initial CO₂ fixation



---

📝 NEET Practice Questions

1. Which pigment is directly involved in light reactions?
A. Chlorophyll b
B. Carotene
C. Chlorophyll a
D. Xanthophyll
✅ Answer: C. Chlorophyll a

2. The first stable product of C4 cycle is:
A. PGA
B. Pyruvate
C. OAA
D. Malate
✅ Answer: C. OAA

Comments

Post a Comment

Popular posts from this blog

Celebrating Teacher’s Day 2025: Honoring the Architects of Knowledge

-
Image
The Origin of Teacher’s Day Teacher’s Day in India commemorates Dr. Sarvepalli Radhakrishnan, born on September 5, 1888. A philosopher, statesman, and the second President of India (1962–1967), Dr. Radhakrishnan believed education was the cornerstone of progress. When students and admirers suggested celebrating his birthday, he humbly proposed that the day be dedicated to honoring all teachers instead. Since 1962, September 5th has been celebrated as Teacher’s Day across the country, a tradition that continues to thrive. Why Teachers Matter Teachers are more than just educators—they are mentors, role models, and catalysts for change. On this Teacher’s Day, let’s reflect on their impact: Shaping Minds: They introduce students to new ideas, critical thinking, and problem-solving skills. Building Character: Beyond academics, teachers instill values like discipline, empathy, and resilience. Inspiring Futures: Many successful individuals credit a teacher for sparking...
Read more

NEET 2025 – Cell: The Unit of Life | NCERT-Based Notes + Diagrams

-
Image
Post Content: Introduction: "Cell: The Unit of Life" is a conceptual and factual chapter. NEET 2025 can include diagram-based MCQs and questions from cell organelles and types of cells. Focus on NCERT keywords and functions. 1. Discovery of Cell Discovered by Robert Hooke in 1665 (cork cell) Cell Theory by Schleiden & Schwann Rudolf Virchow: "Omnis cellula-e-cellula" – cells arise from pre-existing cells 2. Prokaryotic vs Eukaryotic Cells Feature Prokaryote (Bacteria) Eukaryote (Plants/Animals) Nucleus Absent Present Organelles No membrane-bound Membrane-bound Ribosome Type 70S 80S Cell Wall Peptidoglycan Cellulose (plants) 3. Cell Organelles Nucleus: Double membrane, contains nucleolus and chromatin Mitochondria: Powerhouse, double membrane, has its own DNA Plastids: Chloroplast: Green, photosynthesis, has DNA Endoplasmic Reticulum (ER): Rough ER: Protein synthesis Smooth ER: Lipid synthesis Golgi Apparatus: Modifies & packages proteins Lysosome...
Read more

🌱 Plant Kingdom – Bryophytes (Mosses & Liverworts) | NEET 2025 Notes

-
Image
Introduction Bryophytes are often called the “Amphibians of the Plant Kingdom” because they require water for reproduction but can survive on land as well. They form a crucial link between algae and pteridophytes. For NEET aspirants, bryophytes are an important NCERT-based topic that often appear in exams with direct questions. --- General Characteristics of Bryophytes Non-vascular plants (no xylem or phloem) Plant body is thalloid (undifferentiated into true root, stem, and leaves) Anchored by rhizoids instead of roots Reproduction occurs through spores Life cycle shows alternation of generations (gametophyte dominant, sporophyte dependent) --- Classification of Bryophytes Bryophytes are divided into three main groups: 1. Liverworts Example: Marchantia Plant body is dorsiventral, thalloid Asexual reproduction: by fragmentation and gemmae Sexual reproduction: male and female sex organs borne on separate structures 2. Mosses Example: Funaria, Polytrichum Gametophyte has two ...
Read more