| target | 495+/500 |
| author | Senior Sibling |
| name | diagram-bank |
| description | 12th Grade Mandatory Diagram List (PCMB). Covers Physics Ray/Circuit diagrams, Biology Reproductive/Genetics structures, and Chemistry Mechanism visualizations. |
Diagram Bank — 12th Grade "Mark-Magnet" Diagrams
In 12th Grade Science, a diagram is not an "option"—it is a Value Point. An answer without a diagram in Section E (5 Marks) is automatically capped at 4/5.
🧬 Biology (The Most Diagram-Heavy)
- Reproduction:
- TS of Anther (showing 4 layers + Pollen sacs).
- Mature Embryo Sac (7-celled, 8-nucleate).
- Human Sperm (Head, Middle piece, Tail).
- TS of Ovary/Testis.
- Genetics & Molecular:
- DNA Replication Fork (showing Leading/Lagging strands).
- Lac Operon (Switch ON/OFF states).
- tRNA Adapter Molecule (Clover leaf model).
- Biotech & Human Health:
- Antibody Molecule (Y-shaped with H and L chains).
- Cloning Vector pBR322 (Mandatory: Mark all restriction sites).
- Bioreactor (Simple Stirred-tank vs Sparged).
🔭 Physics (Ray & Circuit Precision)
- Optics:
- Ray Diagram: Compound Microscope (Final image at $D$ and $\infty$).
- Ray Diagram: Astronomical Telescope (Normal adjustment).
- Wavefronts: Reflection and Refraction using Huygens' Principle.
- Electricity & Magnetism:
- Cyclotron (Dee structures and path).
- Moving Coil Galvanometer (Internal parts).
- AC Generator (Armature, Rings, Brushes).
- Modern Physics:
- Experimental setup of Photoelectric Effect.
- Energy Level Diagram for Hydrogen atom (Lyman, Balmer, etc.).
- P-N Junction: Forward and Reverse bias circuits.
- Zener Diode as a Voltage Regulator.
🧪 Chemistry (Visualizing Mechanisms)
- Organic Mechanisms:
- Transition state of $S_N 2$ reaction.
- Carbocation formation in $S_N 1$.
- Physical Chemistry:
- Galvanic Cell ($Zn-Cu$ with Salt Bridge).
- Standard Hydrogen Electrode (SHE).
- Fuel Cell ($H_2-O_2$).
- Biomolecules:
- Structure of Glucose (Open vs Pyranose).
- Peptide bond formation.
✍️ Presentation Rules (Senior Sibling)
- The Box: Enclose your diagram in a neat pencil-drawn box.
- Single-Side Labeling: Draw all labels on the Right side with straight horizontal lines.
- Arrows: For Physics, arrows on light rays and current paths are Non-negotiable.
- Scale: A diagram should be roughly 1/3 of a page. Never draw "micro-diagrams".
Command Integration: Use /diagram-drill to get a list of diagrams to practice for a specific chapter.
