PSEB 12th Class Syllabus 2025 Biology

Punjab Board

SYLLABUS
2024-2025

Punjab School Education Board
CLASS-XII
Subject : BIOLOGY

Time: 3 Hrs Total: 100 Marks

Theory: 70 Marks Practical: 25 Marks Internal assessment: 05 Marks

Syllabus (Theory)
Class XII

Session 2023-24

Max Marks 70 Time allowed 3 Hours

Unit Title No. of periods Marks
I Reproduction 30 16
II Genetics and Evolution 40 18
III Biology and Human Welfare 30 12
IV Biotechnology and its Applications 30 10
V Ecology and Environment 30 14
Total 160 70

Unit-I
Reproduction
Chapter-1: Sexual Reproduction in Flowering Plants
Flower structure; development of male and female gametophytes; pollination
- types, agencies and examples; out breeding devices; pollen-pistil
interaction; double fertilization; post fertilization events - development of
endosperm and embryo, development of seed and formation of fruit; special
modes- apomixis, parthenocarpy, polyembryony; Significance of seed
dispersal and fruit formation.
Chapter-2: Human Reproduction
Male and female reproductive systems; microscopic anatomy of testis and
ovary; gametogenesis
-spermatogenesis and oogenesis; menstrual cycle; fertilisation, embryo
development up to blastocyst formation, implantation; pregnancy and
placenta formation (elementary idea); parturition (elementary idea); lactation
(elementary idea).
Chapter-3: Reproductive Health

Need for reproductive health and prevention of Sexually Transmitted
Diseases (STDs); birth control - need and methods, contraception and
medical termination of pregnancy (MTP); amniocentesis; infertility and
assisted reproductive technologies - IVF, ZIFT, GIFT (elementary idea for
general awareness).
Unit-II
Genetics and Evolution
Chapter-4: Principles of Inheritance and Variation
Heredity and variation: Mendelian inheritance; deviations from Mendelism
– incomplete dominance, co-dominance, multiple alleles and inheritance of
blood groups, pleiotropy;
elementary idea of polygenic inheritance; chromosome theory of inheritance;
chromosomes and genes; Sex determination - in humans, birds and honey
bee; linkage and crossing over; sex linked inheritance - haemophilia, colour
blindness; Mendelian disorders in humans - thalassemia; chromosomal
disorders in humans; Down's syndrome, Turner's and Klinefelter's
syndromes.
Chapter-5: Molecular Basis of Inheritance
Search for genetic material and DNA as genetic material; Structure of DNA
and RNA; DNA packaging; DNA replication; Central Dogma; transcription,
genetic code, translation; gene expression and regulation - lac operon;
Genome, Human and rice genome projects; DNA fingerprinting.
Chapter-6: Evolution
Origin of life; biological evolution and evidences for biological evolution
(paleontology, comparative anatomy, embryology and molecular evidences);
Darwin's contribution, modern synthetic theory of evolution; mechanism of
evolution - variation (mutation and recombination) and natural selection
with examples, types of natural selection; Gene flow and genetic drift; Hardy
- Weinberg's principle; adaptive radiation; human evolution.

Unit-III
Biology and Human Welfare
Chapter-7: Human Health and Diseases
Pathogens; parasites causing human diseases (malaria, dengue,
chikungunya, filariasis, ascariasis, typhoid, pneumonia, common cold,
amoebiasis, ring worm) and their control; Basic concepts of immunology -
vaccines; cancer, HIV and AIDS; Adolescence - drug and alcohol abuse.
Chapter-8: Microbes in Human Welfare
Microbes in food processing, industrial production, sewage treatment,
energy generation and microbes as bio-control agents and bio-fertilizers.
Antibiotics; production and judicious use.
Unit-IV
Biotechnology and its Applications
Chapter-9: Biotechnology - Principles and Processes
Genetic Engineering (Recombinant DNA Technology).
Chapter-10: Biotechnology and its Applications

Application of biotechnology in health and agriculture: Human insulin and
vaccine production, stem cell technology, gene therapy; genetically modified
organisms - Bt crops; transgenic animals; biosafety issues, biopiracy and
patents.
Unit-V
Ecology and Environment
Chapter-11: Organisms and Populations
Population interactions - mutualism, competition, predation, parasitism;
population attributes - growth, birth rate and death rate, age distribution.
(Topics excluded: Organism and its Environment, Major Aboitic Factors,
Responses to Abioitic Factors, Adaptations)
Chapter-12: Ecosystem
Ecosystems: Patterns, components; productivity and decomposition; energy
flow; pyramids of number, biomass, energy (Topics excluded: Ecological
Succession and Nutrient Cycles).
Chapter-13: Biodiversity and its Conservation
Biodiversity-Concept, patterns, importance; loss of biodiversity; biodiversity
conservation; hotspots, endangered organisms, extinction, Red Data Book,
Sacred Groves, biosphere reserves, national parks, wildlife, sanctuaries and
Ramsar sites.

Study Materials
Notes

Model Papers Class 6 Notes

Sample Papers Class 7 Notes
Half Yearly Sample Papers Class 8 Notes

Class 9 Notes
Important Resources
Class 10 Notes
Periodic Table
Class 11 Notes
Writing Skills / Formats

Maps of India / World Class 12 Notes

Books and Solutions

NCERT Books
NCERT Book Solutions
HC Verma Chapter Wise Solutions
RD Sharma Solutions
CGBSE Solutions