World’s Biggest Exam

Diversity in Living World

Diversity of living organisms.

Classification of the living organisms (five kingdom classification, major groups and principles of classification within each kingdom).

Systematics and binomial system of nomenclature.

Salient features of animal (non chordates up to phylum level, and chordates up to class level) and plant (major groups; Angiosperms up to subclass) classification.

Botanical gardens, herbaria, zoological parks and museums.

Key points for developing subject matter
• The meaning of being ‘alive’.
• Living organisms show a very large diversity in form and structure ranging from unicellular to very large multicellularwell-differentiated bodies.
• For ease of study, they have been organized into categories and this is called classification.
• Principally, all living organisms can be placed in one or the other of five kingdoms.
• Each kingdom is further subdivided; there are several levels of organisation, the lowest in the hierarchy being the species.
• The Binomial system, literally ‘two names’, of classification is followed, where each organism has a Latin generic name with a specific epithet.
• Zoological parks, Botanical gardens, Herbaria and Natural museums serve as Taxonomical aids.

Structural Organisation in Animals and Plants

Tissues in animals and plants.

Morphology, anatomy and functions of different parts of flowering plants: Root, stem, leaf, inflorescence, flower, fruit and seed.

Morphology, anatomy and functions of different systems of an annelid (earthworm), an insect (cockroach) and an amphibian (frog).

Key points for developing subject matter
• Light and electron microscopes are used as tools for the study of tissues, cells and cell organelles.
• Higher organisation of animals and plants is achieved through assembly of thousands/millions of cells into specialised tissues that in turn form organs and organ systems.
• The organisation of the living body shows division of labour.
• Organisms show increasing complexity in structure and function as we move from the lower to the higher levels.
• Plants and animals exhibit a wide range of organisation from a simple level to the complex.
• Floral characteristics form the basis of classification and identification of Angiosperms. This can be illustrated through semi-technical descriptions of families using suitable examples of wild and cultivated plants.
• The structure of the animal body shows a wide range in morphology and anatomy.

Cell: Structure and Function

Cell : Cell wall, cell membrane and cell organelles (plastids, mitochondria, endoplasmic reticulum, Golgi bodies/ dictyosomes, ribosomes, lysosomes, vacuoles, centrioles) and nuclear organisation. Mitosis, meiosis, cell cycle. Basic chemical constituents of living bodies. Structure and functions of carbohydrates, proteins, lipids and nucleic acids.

Enzymes : Types, properties and function.

Key points for developing subject matter
• The cell organelles are designed to perform tasks such as synthesis, breakdown, respiration and transport.
• Essential processes of cell division – mitosis and meiosis are similar in animals and plants.
• Living bodies contain different categories of micro and macro-molecules.
• Macromolecules are of four broad categories.
• Proteins, the major macro group besides providing structural support, mediate many physiological functions like catalysis, defence, transport, and sensing.
• Enzymes are an important class of proteins responsible for all metabolic activities of the cell.
• Carbohydrates are major energy reserves, and also serve the function of providing structural support to majority of living organisms.
• Lipids serve as major components of membranes, as energy reserves and some hormones. • The DNA has a double helical structure.
• Nucleic acids are the genetic material, and are responsible for determining the protein synthesis.

Plant Physiology

Movement of water, food, nutrients and gases.
Plants and water.
Mineral nutrition.
Respiration.
Photosynthesis.
Plant growth and development.

Key points for developing subject matter
• Cell to cell movement of water, food, gas and nutrients is dependent principally on concentration gradients and diffusion.
• Substances are moved against a concentration gradient through active transport.
• The plants lose water through their stomata.
• Transport of water over larger distances in plants depends on transpiration pull.
• Root pressure is responsible for movement of water up short distances and for guttation.
• Plants require a variety of mineral nutrients for their growth and development.
• Some plants are able to fix atmospheric nitrogen.
• Green plants use the C3 pathway to fix carbon dioxide and synthesize simple sugars in the presence of sunlight.
• Some plants have the C4 pathway.
• Sugars are oxidised by all living organisms to release energy.
• Some organisms derive energy from food anaerobically.
• This energy is trapped as ATP and utilised for all metabolic activities.
• Growth regulators regulate growth and development in plants.

Human Physiology

Digestion and absorption.
Breathing and respiration.
Body fluids and circulation.
Excretory products and elimination.
Locomotion and movement.
Control and coordination.

Key points for developing subject matter
• Food is broken down enzymatically in stages and nutrients absorbed as they pass through the alimentary canal.
• The process of exchange of gases takes place at organ, tissue, cell and organelle levels leading to oxidation of sugars in the cells.
• Gases, nutrients as well as waste products are transported in the body through the vascular system.
• The various components of the blood are involved in diverse functions.
• Metabolic wastes produced in the body are eliminated by excretory system.
• The kidneys play an important role in osmoregulation.
• Movement and locomotion involves interaction of the skeletal and muscular system; the skeleton also protects many parts of the body.
• Control and coordination require functional integration of neural and endocrine systems in the body.
• Sense organs are specialised to receive different stimuli and transmit them to the brain.

Sexual Reproduction

Pollination and fertilisation in flowering plants.
Development of seeds and fruits.
Human reproduction: Reproductive system in male and female, menstrual cycle.
Production of gametes, fertilisation, implantation, embryo development, pregnancy and parturation. Reproductive health – birth control, contraception and sexually transmitted diseases.

Key points for developing subject matter
• Plants show vegetative, asexual and sexual reproduction.
• In Angiosperms, the flowers contain the reproductive organs. They may be unisexual or bisexual.
• There are multitudes of ways of bringing together pollen and the carpel (pollination).
• In nature, pollination is subject to many uncertainties; often barriers to pollination and incompatibility have to be overcome for successful pollination and fertilisation.
• The male gametes are produced in the pollen tube, while the female gamete is produced in the embryo sac.
• Double fertilisation leads to the formation of embryo and the endosperm.
• The ovules in the ovary turn into seed after fertilisation. The ovary turns into a fruit.
• In animals, testes produce sperms and ovaries produce ova.
• Both male and female gametes production is under hormonal regulation; production of ova is a cyclic process.
• During fertilization, sperms migrate through the genital tract to fuse with the ova.
• The genetic makeup of the sperm determines the sex of the unborn child.
• The fertilised egg implants in the uterine wall where it remains connected with the mother till birth.
• The zygote undergoes cleavage, and then passes through different stages of development leading to the formation of three germinal layers.
• After completion of the gestation period, a fully developed baby is delivered.
• Contraceptive methods interfere with one or more of the following: gamete production, ovulation, sperm delivery, fusion of gametes and implantation. These methods of birth control thus help in family planning.
• In IVF the ova is fertilised using a donor sperm outside the body and the fertilised ova is implanted in the female body for further development.
• Abortion is legal, but not recommended for birth control; prenatal sex determination (usually associated with selective female foeticide) is illegal.
• Safe sex can help to prevent sexually transmitted diseases and AIDS.

Genetics and Evolution

Mendelian inheritance.
Chromosome theory of inheritance, deviations from Mendelian ratio (gene interaction- Incomplete
dominance, co-dominance, complementary genes, multiple alleles).
Sex determination in human beings: XX, XY.
Linkage and crossing over.
Inheritance pattern of haemophilia and blood groups in human beings.
DNA: replication, transcription, translation.
Gene expression and regulation.
Genome and Human Genome Project.
DNA fingerprinting.
Evolution: Theories and evidences

Key points for developing subject matter
• Plants and animals show Mendelian inheritance.
• Organisms may also show cytoplasmic inheritance.
• DNA carries information from one generation to the next.
• Human inheritance pattern can be exemplified by pattern of inheritance of blood groups and haemophilia.
• Genes on the same chromosomes show linkage and are inherited together unless crossing over occurs.
• The Lac operon exemplifies a typical model of gene regulation.
• Sequencing of Human DNA under the Human Genome Project aims at finding solutions for genetic disorders and several health problems.
• DNA fingerprinting is also used for identification and crime detection.
• Diversity in animals and plants arises out of variations in the genetic material.
• Mutation is an important source of variation.
• Further, variations in genetic material would affect the entire population over generations to give rise to new species and, therefore, lead to evolution.
• The process of evolution is explained by various theories (Lamarckism, Darwinism and Neo- Darwinism). Different types of evidences support the theories.

Biology and Human Welfare

Animal husbandry.
Basic concepts of immunology, vaccines.
Pathogens, Parasites.
Plant breeding, tissue culture, food production.
Microbes in household food processing, industrial production, sewage treatment and energy
generation. Cancer and AIDS.
Adolescence and drug/alcohol abuse.

Key points for developing subject matter
• Traditionally farm animals have been bred for increased productivity, disease and pest resistance.
• The human body has its own defence mechanism.
• The defence system is constantly under attack from diverse sources – pollutants, chemicals and infectious organisms.
• Our body is capable of producing millions of types of antibodies to trap/remove and overcome the adverse effects of these foreign bodies/chemicals.
• However, against some infectious organisms we need to develop antibodies in advance, i.e. acquired immunity.
• Vaccination can help in developing immunity to specific diseases.
• Genetically engineered micro organisms are serving as bioreactors for production of vaccines and drugs.
• Infectious organisms like helminths (Ascariasis, Filaria), protozoa (Amoebiasis, Malaria), bacteria (Typhoid, Pneumonia), viruses (common cold, AIDS) and fungi (Ring worm) attacks specific systems of our body and produce characteristic symptoms.
• Each infectious organism, therefore, requires individual preventive measures.
• Some of these preventive measures demand improved personal hygiene and living conditions.
• Traditional plant breeding has been the method of creating varieties that are high on yield, resistance to pests and diseases and adapted to a given climatic condition. This has been the source of green revolution in India.
• New methods of propagation using tissue culture and genetic alteration using rDNA technology provide novel methods of crop improvement, horticulture, pest resistance.
• Microbes thrive by degradation/conversion of organic and inorganic compounds.
• These characteristics of microbes can be exploited to produce household products (yoghurt/ vinegar), for industrial production, treatment of sewage and energy generation.
• Diseases like cancer and AIDS – the major cause of death in the modern world – need adequate preventive/control measures.
• Some people who are unable to handle the emotional stress and strain of growing up find apparent relief in actions like drug and alcohol consumption; in reality a non-solution since it leads to severe repercussions like physiological and emotional disorders.

Biotechnology and its Applications

Recombinant DNA technology.
Applications in Health, Agriculture and Industry.
Genetically modified (GM) organisms; biosafety issues.
Insulin and Bt cotton.

Key points for developing subject matter
• DNA is a long polymer that can be edited by cutting and joining in any desired way. The edited DNA molecule (recombinant DNA) can be reintroduced into microbes, animals or plants to create genetically modified (GM) organisms or transgenics.
• rDNA technology is the very basis of many applications in biotechnology – for example to produce desired drugs and for gene therapy.
• rDNA technology has also played a major role in production of GM foods which have the advantage of high yields, pest and disease resistance.
• Use of GM food and crops has raised several questions regarding its bio-safety from the point of human consumption, environment and other social issues.
• A combination of classical breeding with rDNA technology and genetic modification has great potential for animal breeding.
• While cloning has been in use for plants since several decades, use of the technique in animals, particularly human cloning, raises several ethical and other issues.
• rDNA technology (gene therapy) can provide effective remedies for several genetic disorders.
• Bioreactors have been developed for production of vaccines and drugs.

Ecology and Environment

Ecosystems: Components, types and energy flow.
Species, population and community.
Ecological adaptations.
Centres of diversity and conservation of biodiversity, National parks and sanctuaries. Environmental issues.

Key points for developing subject matter
• The living organisms in their environment form a structural and functional unit in terms of energy flow (ecological pyramids).
• The biotic and abiotic components within an ecosystem interact with each other.
• Several types of ecosystems can be classified and identified in nature depending on the climate, habitat, energy flow pattern and the physiognomy.
• In nature, organisms do not occur singly but exist as populations and communities.
• Plants and animals are adapted to their habitats such as in deserts and in water.
• Several factors affect biodiversity including natural and anthropogenic activities.
• In India, women have played a major role in conservation of plants, animals and natural resources.
• The need of the present day is to conserve biodiversity for a sustainable living; several conservation methods have been adopted.
• Conservation of biodiversity may be in situ or ex situ.
• The ‘Silent Valley’ as a case study, to understand the value of environmental impact assessment and the role of peoples’ participation.
• Introduction to the idea that new products, processes and ideas related to biodiversity can be patented (Intellectual Property Rights, IPR).
• Pollution, deforestation, global warming, ozone layer depletion, underground water level and threat to biodiversity (with special reference to wild life) are some among many environmental concerns