Biology

---
target: 495+/500
author: Senior Sibling
name: biology
description: Master framework for CBSE 12th Biology. Genetics to Biotechnology.
stream: pcmb
---

# Biology — CBSE Grade 12 (2026-27)

## Syllabus Coverage
| Unit | Chapters | Theory Marks | Practical Marks |
|------|----------|--------------|-----------------|
| VI | Reproduction | 16 | 30 |
| VII | Genetics & Evolution | 20 | |
| VIII| Biology in Human Welfare| 12 | |
| IX | Biotechnology | 12 | |
| X | Ecology | 10 | |

## Chapter-by-Chapter Deep Dive
- **Genetics**: Mendelian laws, Linkage, DNA structure, Fingerprinting.
- **Biotech**: PCR, Recombinant DNA, pBR322.
- **Reproduction**: Double fertilization, Gametogenesis.

## High-Yield Topics (490+ Strategy)
- **Molecular Basis of Inheritance** (DNA Replication/Transcription).
- **Biotechnology Principles** (Process of Recombinant DNA).
- **Human Reproduction** (Male/Female systems).

## Derivation/Proof Bank
1. Proof of DNA as genetic material (Hershey-Chase).
2. Hardy-Weinberg equilibrium proof.

## Formula Bank
- $p^2 + 2pq + q^2 = 1$ (Hardy-Weinberg).

## Diagram Bank
- Human Sperm structure.
- Transcription Unit.
- pBR322 Plasmid.
- Polymerase Chain Reaction (PCR).

## CBSE Question Patterns (12th specific)
- 1M: Identification of codon.
- 3M: Describing a biotech tool.
- 5M: Long answer on Genetics with crosses.

## NEET/JEE Alignment
- **NEET**: 100% NCERT line-by-line focus is mandatory. High weightage for Genetics and Biotech.

## Practical Component
- **Experiments**: Pollen germination, DNA isolation from plant material (Onion/Spinach).
- **Viva**: What is the function of the buffer in DNA isolation?

## Common Mistakes (12th specific)
- Wrong labelling of diagrams.
- Confusing between Transcription and Translation.

## Internal Assessment Strategy (30 marks)
- Neat diagrams in the record book are a must.

## Answer Writing for 12th
- Use bullet points. Underline scientific names.