ISC Biology Syllabus Class 12 2024-25 | PDF Download

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Revised ISC Class 12 Biology Syllabus 2024-25

Recently, CISCE, The Council for the Indian School Certificate Examinations has released the revised ISC Biology Syllabus for Class 12 for the academic session 2024-25. 

ISC Class 12 Biology syllabus 2025 lays the groundwork for many other subjects you might study later. If you want to pursue fields like medicine, biotechnology, genetics, or environmental science in college, it's important to have a good grasp of biological concepts mentioned in the ISC Biology Syllabus for Class 12. 

Biology requires lots of time to perform well in exams. Subjects like Class 12 ISC Physics or ISC Chemistry can be combined into the study routine for exam preparation using the revised ISC Syllabus.

Download the Class 12 ISC Biology Syllabus PDF for the academic session 2024-25.

2024-25 Latest Syllabus 

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ISC Class 12 Biology Syllabus 2024-25

PAPER - 1 Unit Total Weightage
Reproduction 16 Marks
Genetics and Evolution 15 Marks
Biology and Human Welfare 14 Marks
Biotechnology and its Applications 10 Marks
Ecology and Environment 15 Marks
TOTAL 70 Marks
PAPER - 2 Work Marks
Practical 15
Project Work 10
Practical File 5

ISC Syllabus Class 12 Biology 2024-25: Marks Distribution

The Class 12 ISC Syllabus of Biology Subject consists of two papers. Paper I is theoretical and Paper II is Practical including project work practical file. The marks in the Biology paper are distributed as follows: 

Paper I: Theory- 3 hours (70 marks)

Paper II: This paper is of a total of 30 Marks, which is divided as follows: 

(i) Practical:  3 hours (15 Marks)

(ii) Project Work - 10 marks

(iii) Practical File - 5 marks

ISC Biology Syllabus Class 12 2025: PAPER II 

Class 12 Biology Paper is divided as follows: 


1)Taxonomy: Study floral characteristics through the dissection of flowers, drawing floral formulas and diagrams of the following families: 

(i) Malvaceae: type – China rose / Hollyhock. 

(ii) Leguminosae: subfamily – Papilionaceae – type – Sweet pea/ Pea/ Bean/ Sesbania/ Clitoria (single flower). 

(iii) Solanaceae: type – Petunia / Datura / Brinjal Flower / Solanum nigrum. 

(iv) Liliaceae: type – Onion or Amaryllidaceae – type – Lily/Spider lily/ Tiger lily/ Tube rose/ Gladiolus. 

Floral characteristics should be explained by the dissection of flowers. Students should be taught how to cut vertical sections of the flower and draw accurately labeled diagrams. The technique of drawing floral diagrams with the mother axis in the right position is necessary. The floral formula should be correctly written. Identification of the correct family giving reasons, the technique of cutting T.S. and L.S. of ovary should be explained and accordingly, correct labelled-diagram should be drawn. 

Students should know the examples of plants (belonging to each family) that are of economic importance. The examples of common names of plants must be supported with correct scientific names as well. 

NOTE: In the examination, candidates will be tested on any one of the above-mentioned families. 

2) Simple biochemical and physiological experiments 

(i) Study of arrangement/distribution of stomata in dicot and monocot leaves. 

(ii) Study of soils from two different sites. Collect soil samples from two different areas and make a comparative study of their texture, moisture content, humus content, water-holding capacity, and pH. 

Guidelines for collection of soil samples: 

• Texture - loamy, sandy, and clayey soil. 

• Moisture content – Soil samples are to be collected from a dry place and a wet place. Alternatively, samples of soil can be dried to different degrees in the oven/by keeping in sun. 

• Humus Content – Collect one sample from roadside/barren land and one sample from garden/cultivated field.

 • Water holding capacity – Pour given amount of water in known weight of soil sample and record the volume of water retained by the soil sample. 

• pH – Add water to the soil sample and test with pH paper. Students should be taught to set up and demonstrate the experiments with correct diagram of the setup, record their observations methodically, and give conclusions. This will give a clear idea of the physiological processes. Questions can be asked based on the above physiological processes studied. 

(iii) To study the effect of enzyme action at three different temperatures and pH on starch solution. Effect of enzyme (amylase/ diastase) action at three different temperatures (low- below 10o C, optimum - 37o C and high – above 70o C) and pH (acidic, neutral, and basic) on starch solution. 

(iv) To isolate DNA from available plant material. Isolation of DNA from spinach leaves, green pea seeds, pulp of banana and papaya. Take about 5 gm of pulp of banana into a beaker and add 50 ml of extraction fluid (1.5gm table salt +10 ml liquid detergent +90 ml distilled water). Place the beaker in a water bath set at 60 °C for 15 minutes. Stir gently with a glass rod. Filter 5ml of cooled content into a clean test tube and add 5ml of cold 90% ethanol. DNA molecules separate out and appear as white fibres.

 3) Slide preparation 

(i) Germination of pollen grain in a nutrient medium. (ISC Revised Syllabus 2025) 8 

(ii) T.S. of ovary of any locally available flower, to show marginal/axile placentation. 

(iii)T.S. of a hydrophyte stem. 

(iv) T.S. of a xerophytic leaf (Nerium). 

(v) L.S. of monocot and dicot seed (soaked seeds of maize/wheat, pea/ bean.) The technique of staining and mounting neatly should be explained. Students should also know how to make labelled outline diagrams. They should also be taught to identify the mount under low/ high power of microscope. Two identifying features of the above need to be mentioned. 

4) Spotting: (three minutes to be given for each spot which includes identification, drawing a labelled diagram, and writing at least two identifying characteristics). 

NOTE: Spotting must be done on a separate answer sheet during examination, which should be handed over to the Examiner immediately after spotting. 

(i) Identify and comment on the following: 

(a) T.S. of ovary of mammal (Permanent slide). 

(b) T.S. of testis of mammal (Permanent slide). 

(c) Germinating pollen grain (slide/chart). 

(d) T.S. of ovary to show the type of placentation (marginal, axile, basal (LS), parietal). 

(e) T.S. of blastula / blastocyst of a mammal (chart/ slide). 

(f) Whole mount of Plasmodium sporozoite (slide /chart). 

(g) Whole mount of Entamoeba histolytica trophozoite (slide/chart). 

(h) Preserved specimen/ chart/ model of Ascaris. 

(ii) Comment upon ecological adaptations of plants and animals. Models/ virtual images/ charts of one plant and one animal found in xeric and aquatic habitats. Examples: Hydrilla, cactus, fish, and camel.

(iii) Flowers adapted to pollination by different agencies – insects and wind. Students should be able to identify the type of pollination of the given flower, draw the diagram of the flower, and give two reasons for the type of pollination. Example: Hibiscus and grass. Students should be taught how to identify, draw, label, and give significantly visible characteristics as observed, of each spot, in a given time of three minutes. ‘T.S.’, ‘model’, ‘whole mount’, ‘chart’, ‘image’ of the specimen should be mentioned as a part of identification.

Project Work

  • The project work is to be assessed by a Visiting Examiner appointed locally and approved by the Council.
  • The candidate is to creatively execute one project/assignment on an aspect of biology.
  • Preference is to be given to handwritten investigatory projects. Teachers may assign or students may choose any one project of their choice. Students can choose any other project besides the ones indicated in the list. Following is only a suggestive list of topics:

(i) Genetic disorders

(ii) Gene therapy

(iii) Human Genome Project

(iv) DNA fingerprinting

(v) Bio-piracy

(vi) Cancer

(vii) AIDS/Hepatitis

(viii) Drug addiction and community

(ix) Role of micro-organisms in industry

(x) Human population.

(xi) Mendelian Inheritance

(xii) Environmental resistance

(xiii) Traditional and modern methods: Study of a few traditional methods of pest deterrence vis-a-vis modern methods of pest control - the viability of traditional methods in today's scenario and limitations and dangers of modern methods.

(xiv) Role of agrochemicals in increasing food production.

Practical File 

The Visiting Examiner is required to assess students on the basis of the Biology Practical file maintained by them during the academic year. Each practical done during the year needs to be recorded by the student in the Practical file and the same must be checked, signed, and dated by the teacher.

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