BIOLOGY (863)
CLASS XII
There will be two papers in the subject: Paper II: Practical: 3 hours ... 15 marks
Paper I: Theory: 3 hours ... 70 marks Project Work … 10 marks
. Practical File … 5 marks
PAPER I- THEORY: 70 Marks
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
ISC REVISED SYLLABUS 2026 1
, PAPER I –THEORY – 70 Marks fruit formation. Significance of dispersal of
seeds.
All structures (internal and external) are required
to be taught along with diagrams. Post-fertilisation events - embryo formation
(monocot and dicot); types of endosperm
1. Reproduction (cellular, nuclear and helobial); definition of
(i) Sexual reproduction in flowering plants perisperm.
Flower structure; development of male and (ii) Human Reproduction
female gametophytes; pollination - types, Male and female reproductive systems;
agencies and examples; outbreeding microscopic anatomy of testis and ovary;
devices; pollen-pistil interaction; artificial gametogenesis - spermatogenesis and
hybridisation, double fertilization; post oogenesis; menstrual cycle; fertilisation,
fertilization events - development of embryo development upto blastocyst
endosperm and embryo, development of formation, implantation; pregnancy and
seed and formation of fruit; special modes - placenta formation (elementary idea);
apomixis, parthenocarpy, polyembryony; parturition (elementary idea); lactation
Significance of seed dispersal and fruit (elementary idea).
formation.
Organs of male and female reproductive
Pre-fertilisation structures and events. system and their functions; internal structure
Structure of microsporangium, T.S. of anther of testis and ovary to be taught with the help
microsporogenesis, structure and of diagrams; gametogenesis-
development of pollen grain, viability of spermatogenesis (including spermiogenesis
pollen grain, economic importance of pollen and spermiation) oogenesis; hormonal
grain. Pistil – structure of megasporangium control of gametogenesis, structure of sperm
(L.S. of anatropous ovule), and mature ovum, menstrual cycle - different
megasporogenesis, structure and phases and hormone action, differences
development of female gametophyte. between oestrous and menstrual cycle,
menarche and menopause, physico-chemical
Types of pollination (autogamy, events during fertilisation, implantation,
chasmogamy, cleistogamy, geitonogamy, embryonic development up to blastocyst
xenogamy), adaptations in flowers formation, important features of human
pollinated by wind, water and insects. embryonic development (formation of heart,
Advantages of self and cross-pollination. limbs, digits, appearance of hair on head,
Contrivances for prevention of self- eyelashes, separation of eye lids, external
pollination. Pollen-pistil interaction in terms genital organs and first movement of foetus
of incompatibility/compatibility, events with reference to time period) placenta and its
leading to fertilisation, artificial functions (structure and the types of placenta
hybridisation: procedure (emasculation and not required). Parturition; lactation –
bagging), and its significance in plant hormonal control and importance.
breeding); definition of triple fusion and
double fertilization, significance of double (iii) Reproductive Health
fertilisation, changes in the ovary and ovule Need for reproductive health and prevention
for seed and fruit formation; apomixis, of Sexually Transmitted Diseases (STDs);
polyembryony, parthenocarpy to be birth control - need and methods,
explained briefly. Fruits to be classified into contraception and medical termination of
true and false, structure (L.S) of a typical pregnancy (MTP); amniocentesis; infertility
fruit (mango and coconut); Internal and assisted reproductive technologies
structure of dicot (bean) and monocot (elementary idea for general awareness).
(maize) seeds; definition, differences and
examples of albuminous and non- Definition of reproductive health, programs of
albuminous seeds. Significance of seed and reproductive health (family planning, RCH),
2
ISC Examination Year 2026
CLASS XII
There will be two papers in the subject: Paper II: Practical: 3 hours ... 15 marks
Paper I: Theory: 3 hours ... 70 marks Project Work … 10 marks
. Practical File … 5 marks
PAPER I- THEORY: 70 Marks
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
ISC REVISED SYLLABUS 2026 1
, PAPER I –THEORY – 70 Marks fruit formation. Significance of dispersal of
seeds.
All structures (internal and external) are required
to be taught along with diagrams. Post-fertilisation events - embryo formation
(monocot and dicot); types of endosperm
1. Reproduction (cellular, nuclear and helobial); definition of
(i) Sexual reproduction in flowering plants perisperm.
Flower structure; development of male and (ii) Human Reproduction
female gametophytes; pollination - types, Male and female reproductive systems;
agencies and examples; outbreeding microscopic anatomy of testis and ovary;
devices; pollen-pistil interaction; artificial gametogenesis - spermatogenesis and
hybridisation, double fertilization; post oogenesis; menstrual cycle; fertilisation,
fertilization events - development of embryo development upto blastocyst
endosperm and embryo, development of formation, implantation; pregnancy and
seed and formation of fruit; special modes - placenta formation (elementary idea);
apomixis, parthenocarpy, polyembryony; parturition (elementary idea); lactation
Significance of seed dispersal and fruit (elementary idea).
formation.
Organs of male and female reproductive
Pre-fertilisation structures and events. system and their functions; internal structure
Structure of microsporangium, T.S. of anther of testis and ovary to be taught with the help
microsporogenesis, structure and of diagrams; gametogenesis-
development of pollen grain, viability of spermatogenesis (including spermiogenesis
pollen grain, economic importance of pollen and spermiation) oogenesis; hormonal
grain. Pistil – structure of megasporangium control of gametogenesis, structure of sperm
(L.S. of anatropous ovule), and mature ovum, menstrual cycle - different
megasporogenesis, structure and phases and hormone action, differences
development of female gametophyte. between oestrous and menstrual cycle,
menarche and menopause, physico-chemical
Types of pollination (autogamy, events during fertilisation, implantation,
chasmogamy, cleistogamy, geitonogamy, embryonic development up to blastocyst
xenogamy), adaptations in flowers formation, important features of human
pollinated by wind, water and insects. embryonic development (formation of heart,
Advantages of self and cross-pollination. limbs, digits, appearance of hair on head,
Contrivances for prevention of self- eyelashes, separation of eye lids, external
pollination. Pollen-pistil interaction in terms genital organs and first movement of foetus
of incompatibility/compatibility, events with reference to time period) placenta and its
leading to fertilisation, artificial functions (structure and the types of placenta
hybridisation: procedure (emasculation and not required). Parturition; lactation –
bagging), and its significance in plant hormonal control and importance.
breeding); definition of triple fusion and
double fertilization, significance of double (iii) Reproductive Health
fertilisation, changes in the ovary and ovule Need for reproductive health and prevention
for seed and fruit formation; apomixis, of Sexually Transmitted Diseases (STDs);
polyembryony, parthenocarpy to be birth control - need and methods,
explained briefly. Fruits to be classified into contraception and medical termination of
true and false, structure (L.S) of a typical pregnancy (MTP); amniocentesis; infertility
fruit (mango and coconut); Internal and assisted reproductive technologies
structure of dicot (bean) and monocot (elementary idea for general awareness).
(maize) seeds; definition, differences and
examples of albuminous and non- Definition of reproductive health, programs of
albuminous seeds. Significance of seed and reproductive health (family planning, RCH),
2
ISC Examination Year 2026
