Subject Pattern : ISC Class XII Biology Paper Pattern And Information For Exam Preparation
CLASS XII
There will be two papers in the subject.

Paper I: Theory: 3 hours ... 70 marks
Paper II: Practical: 3 hours ... 20 marks
Project Work … 7 marks
Practical File … 3 marks

PAPER I ' THEORY - 70 Marks
There will be one paper of 3 hours duration divided into 2 parts.

Part 1 (20 marks) will consist of compulsory short answer questions, testing knowledge, application and skills relating to elementary/fundamental aspects of the entire syllabus.


Part 2 (50 marks) will be divided into two Sections A and B. Candidates are required to answer three out of five questions from Section A and two out of four questions from Section B. Each question in this part shall carry 10 marks.

SECTION - A
1. Multicellularity: Structure and Function - Plant Life

Forms and function
(i) Tissues: types of plant tissues: Meristematic Classification of Meristematic tissue, tunicacorpus theory, histogen theory, shoot apex and root apex.

Permanent Tissues: Structure and function of simple tissues (parenchyma, collenchyma and sclerenchyma) and complex tissues (xylem and phloem), types of vascular bundles, T. S of young dicot and monocot stem, T. S of young dicot and monocot root and V. S. of dicot and monocot leaf. Secondary growth: brief idea of formation of secondary xylem and secondary phloem by cambium ring formation, annual rings, heartwood and sapwood.

(ii) Absorption and movement of water in plants: diffusion, imbibition, osmosis, osmotic pressure, turgor pressure/ pressure potential wall pressure, water potential, diffusion pressure deficit. Types of soil water, mechanism of water absorption (active and passive absorption), root pressure, transpiration, transpiration pull theory for ascent of sap, mechanism of opening and closing of stomata (active potassium theory), guttation.

(iii) Mineral nutrition: macronutrients and micronutrients (role and deficiency symptoms), criteria for essentiality of elements, aeroponics and hydroponics, passive absorption (ion exchange mechanism) and active absorption of mineral nutrients, nitrogen nutrition in plants.


(iv) Modes of nutrition: parasitic, saprophytic, symbiotic and insectivorous (brief idea with examples), photosynthesis: ultra structure of chloroplast, photochemical and biosynthetic phases, absorption and action spectra, factors influencing photosynthesis, photophosphorylation; photorespiration, transport of solutes.


(v) Reproduction and development in angiosperms: vegetative reproduction, sexual reproduction: development of male and female gametophytes, types of ovules, placentation, pollination, fertilisation and formation of endosperm, embryo, seed and fruits (broadly classified). Apomixes, Polyembryony.


(vi) Differentiation and organ formation.


(vii) Plant growth: phases of growth, growth rate, measurement of growth, factors affecting growth, role of growth regulators, seed dormancy and germination, apical dominance, senescence and abscission, movements in plants (tropic and nastic).


(viii) Photomorphogenesis in plants including a brief account of phytochrome.


2. Multicellularity: Structure and Function - Animal Life
(i) Tissues: epithelial; connective; muscular; nervous (location, structure and function).
(ii) Nutrition (human): Organs of digestive system (histology not required), digestive process and disorders of the digestive system.

(iii) Respiration (human): Organs of respiratory system, breathing mechanism (inspiration and expiration), pulmonary gas exchange, transport of respiratory gases, pulmonary air volumes and lung capacities. Disorders of respiratory system.

(iv) Circulation: closed and open vascular systems, structure of human heart, cardiac cycle, systemic and pulmonary circulation, portal system, arterial blood pressure, types of hearts, origin and conduction of heart beat, blood vessels (structure and adaptation), lymphatic system. ABO group, coagulation of blood.

(v) Excretion: ammonotelism, ureotelism, uricotelism, structure of human kidney (L.S.), structure of nephron, role of skin and lungs in excretion, physiology of urine formation, counter current system; functions of the kidney; dialysis. Disorders of the excretory system.

(vi) Endocrine System (human): hormones of pituitary, thyroid, parathyroid, thymus, pancreas, adrenal glands and gonads; effect of hyposecretion and hypersecretion, feedback mechanism.

(vii) Nervous System (human): Central, autonomic and peripheral, structure of spinal cord, reflex action, transmission of nerve impulse, saltatory conduction; receptors (mechanoreceptor, chemoreceptor, photoreceptor and thermoreceptors), sense organs (eye and ear).

(viii) Locomotion: joints, structure of skeletal muscle, sliding filament theory of muscle contraction, classification of muscles on the basis of function, red and white muscles, summation, tetanus and rigor mortis. Disorders of muscular and skeletal system.

(ix) Reproduction (human): internal structure of human testis and ovary, menstrual cycle, gametogenesis, embryonic development in mammals (up to three germ layers). Medical termination of pregnancy, infertility.

(x) Growth, Ageing and Death: types of growth, growth curve, morphological and physiological changes during ageing, causes of death.


SECTION - B
3. Origin and Evolution of Life

(i) Origin of life: living and nonliving; chemical evolution; organic evolution - Oparin ideas, Miller-Urey experiments; interrelationship among organisms and evidences of evolution, morphological evidence, homology and analogy, vestigial organs, physiological, embryological, palaeontological (fossils) and biogeographical evidences.

(ii) Theories of evolution: Lamarckism: evidences in favour of Lamarckism (giraffe's neck), criticism of Lamarckism; Darwinism: basic postulates of Darwinism, drawbacks of Darwinism, Neo-Darwinism; variations: causes of variation, selected examples of natural selection (DDT resistance in mosquito, malaria in relation to G-6-P-D deficiency and sickle-cell anaemia); artificial selection; adaptations (Lederberg's replica plating experiment). Human evolution: Dryopithecus, Australopithecus, Homo erectus, Homo neanderthalensis, Cromagnon man and Homo sapiens; differences between apes and man.


4. Applications of Biology
(i) Domestication of plants and crop improvement: methods of crop improvement: selection, hybridisation, plant breeding, plant introduction, tissue culture; uses of medicinal plants: Cinchona calisaya (quinine), Azadirachta (neem) Ocimum sanctum (tulsi), Aegle marmelos (bel), Emblica officinalis (amla), Adhatoda vasica (vasaka), Withana somnifera (ashwagandha), Aloe vera.

(ii) Crops today: Gene pool and genetic conservation, gene banks, cryopreservation.
(iii) Biofertiliser: green manure, nitrogen fixation' symbiotic and non-symbiotic organisms.
(iv) Pesticides: advantages and disadvantages of pesticides. Bioinsecticides and bioherbicides. Integrated Pest Management (IPM).
(v) Human Diseases: body’s defence mechanisms: (specific and non-specific); immune disorders (SCID and AIDS); allergies, interferons, communicable diseases: causative agent, symptoms and prevention of the following: bacterial diseases (tuberculosis, typhoid, pneumonia, cholera, tetanus), viral diseases (chicken pox, common cold, poliomyelitis, rabies and hepatitis), protozoa (malaria and amoebiasis), helminthes (ascariasis and filariasis); non-communicable diseases: diseases of the heart, diabetes (types), cancer (types, causes, diagnosis and treatment); human genetic disorders: (haemophilia, albinism, Down’s syndrome,


Klinefeltor’s syndrome, Turner syndrome). Rh factor incompatibility; amniocentesis. Genetic counselling; a brief idea of stem cells, organ transplants and immunosuppression.

(vi) Mental Health and Community Health: types, causes and treatment of mental illness; causes of addiction; activities of community health services.
(vii) Biomedical Engineering: (only basic concepts) Instruments ' ECG, EEG, CT scan, ultrasound, MRI, pacemakers, implants, disposables, external prosthesis.
(viii) Human population: population growth curves, causes of increase in population.


PAPER II
PRACTICAL WORK ' 20 Marks

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

(i) Malvaceae - type-china rose / hollyhock.
(ii) Compositae ' type -sunflower/ Cosmos/ marigold (with single whorled ray florets).
(iii) Leguminosae - subfamily - papilionaceae - type-sweet pea/ pea /bean.
(iv) Solanaceae - type ' petunia / datura.
(v) Liliaceae - type ' onion or Amarallydaceae - type ' lily.

2) Simple biochemical and physiological experiments -
(i) Demonstration of plasmolysis
(ii) Demonstration of osmosis in living plant cells (potato osmoscope).
(iii) Demonstration of unequal transpiration in leaves.
(iv) To demonstrate the effect of different intensities of light on photosynthesis.
(v) To demonstrate that oxygen is evolved during photosynthesis.
(vi) Effect of different carbon dioxide concentrations on the rate of photosynthesis.

3) Studies of the following with the help of models. (Students would be required to sketch, label and identify the various parts in the organ/system and know their role in the body).

(i) Human digestive system.
(ii) Human heart (V.S.).
(iii) Human eye (V.S.).
(iv) Human ear (V.S.).
(v) Human brain (external and V.S.).
(vi) Human kidney (V.S.).

4) Slide preparation -
(i) T.S. of dicot root.
(ii) T.S. of monocot root.
(iii) T.S. of dicot stem.
(iv) T.S. of monocot stem.
(v) Striated muscles of cockroach.
(vi) Nerve cells from spinal cord of a vertebrate (goat).
(v) Identification of human blood groups.

Blood group can be detected by noting the clumping behaviour of blood. Antisera A, B and D should be used.
The technique of collecting the material from the correct location, teasing the material, staining and mounting neatly should be explained. Identification of the mount under the microscope should be taught. Students must know the use of low power and high power microscope. They should also know how to make labelled outline drawings.

5) Spotting: (Three minutes to be given for each spot. Separate continuation sheets should be used which need to be collected at the end of spotting)

(i) Identify and comment on permanent slides of:
a) T.S of monocot and dicot stem.
b) T.S. of monocot and dicot root.
c) T.S. of monocot and dicot leaf.
d) T.S. of spinal cord of mammal.
e) T.S. of bone of mammal.
f) T.S. of ovary of mammal.
g) T.S. of testis of mammal.

(ii) Comment on experimental set up studied in physiology


PROJECT WORK AND PRACTICAL FILE ' 10 Marks
Project Work ' 7 Marks
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. 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 projects:

(i) Diabetes.
(ii) Endocrine glands.
(iii) Vegetarianism/non-vegetarianism.
(iv) Role of micro-organisms in industry.
(v) Drug addiction and community.
(vi) Balanced diet.
(vii) Human population.
(viii) Cancer.
(ix) AIDS/Hepatitis.
(x) Cell organelles.

Ecology
(i) Abiotic and biotic factors.
(ii) Food chains.
(iii) Ecological pyramids.
(iv) Ecosystems.
(v) Biomass and bionumber.
(vi) Carbon, nitrogen and mineral cycles.
(vii) Environmental resistance.
(viii) Ecological impact of pollution.
(ix) Acid rain.
(x) Ozone layer.
(xi) Conservation of natural resources.
(xii) Green house effect.

Practical File ' 3 Marks
The Visiting Examiner is required to assess students on the basis of the Biology Practical file maintained by them during the academic year.