Class 12 is a turning point in a student’s life. The marks scored in Class 12 help them to get admission to prestigious colleges across India. Students who have opted for Biology subjects aim to build their careers in medical- or Biology-related fields. Hence, having a deep understanding of Biology subject is very crucial. Here, we have provided the ISC Class 12 Biology Syllabus, along with the mark-wise weightage for every chapter. Students can also download the ISC Class 12 syllabus PDF from the link below.
Download ISC Class 12 Biology Syllabus PDF 2023-24
Before going into the syllabus, students must have a look at the marks weightage of the ISC Syllabus for Class 12 Biology.
Marks Weightage of the ISC Class 12 Biology Syllabus
The Biology theory paper is of 70 marks consisting of 3 hours of time duration.
| S. No. | Unit | Total Weightage |
| 1 | Reproduction | 16 Marks |
| 2 | Genetics and Evolution | 15 Marks |
| 3 | Biology and Human Welfare | 14 Marks |
| 4 | Biotechnology and Its Applications | 10 Marks |
| 5 | Ecology and Environment | 15 Marks |
| Total | 70 Marks | |
Internal choice will be available in two questions of 2 marks each, two questions of 3 marks each and all the three questions of 5 marks each.
ISC Syllabus for Class 12 Biology (Theory)
1. Reproduction
(i) Reproduction in organisms
Reproduction, a characteristic feature of all organisms for continuation of species; modes of reproduction – asexual and sexual reproduction; asexual reproduction – binary fission, sporulation, budding, gemmule formation, fragmentation; vegetative propagation in plants.
(ii) Sexual reproduction in flowering plants
Flower structure; development of male and female gametophytes; pollination – types, agencies and examples; outbreeding 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.
(iii) Human reproduction
Male and female reproductive systems; microscopic anatomy of testis and ovary; gametogenesis – spermatogenesis and oogenesis; menstrual cycle; fertilisation, embryo development upto blastocyst formation, implantation; pregnancy and placenta formation (elementary idea); parturition (elementary idea); lactation (elementaryidea).
(iv) 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).
2. Genetics and Evolution
(i) 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; chromosomal theory of inheritance; chromosomes and genes; sex determination – in humans, fruit fly, birds, honey bee and grasshopper; linkage and crossing over; mutation; sex linked
inheritance: Mendelian disorders in humans; chromosomal disorders in humans.
(ii) 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; human genome project; DNA fingerprinting.
(iii) Evolution
Origin of life; biological evolution and evidences for biological evolution (palaeontology, 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.
3. Biology and Human Welfare
(i) Human health and diseases
Pathogens; parasites causing human diseases (common cold, dengue, chikungunya, typhoid, pneumonia, amoebiasis, malaria, filariasis, ascariasis, ring worm) and their control; Basic concepts of immunology – vaccines; cancer, HIV and AIDS; Adolescence – drug and alcohol abuse.
(ii) Strategies for enhancement in food production
Improvement in food production: green revolution, plant breeding, tissue culture, single cell protein, biofortification, apiculture and animal husbandry.
(iii) Microbes in human welfare
In household food processing, industrial production, sewage treatment, energy generation and microbes as biocontrol agents and biofertilisers. Antibiotics.
4. Biotechnology and Its Applications
(i) Biotechnology – Principles and processes
Genetic Engineering (recombinant DNA technology).
(ii) Biotechnology and its applications
Applications 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 biopatents.
5. Ecology and Environment
(i) Organisms and populations
Population interactions – mutualism, competition, predation, parasitism; population attributes – birth rate and death rate, age distribution.
(ii) Ecosystem
Ecosystems: patterns, components; productivity and decomposition; energy flow; pyramids of number, biomass, energy.
(iii) Biodiversity and its conservation
Concept of biodiversity; patterns of biodiversity; importance of biodiversity; loss of biodiversity; biodiversity conservation; hotspots, endangered organisms, extinction, Red Data Book, biosphere reserves, national parks, sanctuaries and Ramsar sites.
(iv) Environmental issues
Air pollution and its control; water pollution and its control; agrochemicals and their effects; solid waste management; radioactive waste management; greenhouse effect and climate change; ozone layer depletion; deforestation; any one case study as success story addressing environmental issue(s).
Students can also get the syllabus of all the subjects of Classes 11 and 12 in one place by clicking the ISC Syllabus. Keep learning and stay tuned for further updates on ICSE/CBSE/State Board and other competitive exams. Download BYJU’S – The Learning App and subscribe to the YouTube channel to access interactive videos.
this app is really helpful