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REVISION NOTES FOR CBSE CLASS 12 BIOLOGY CHAPTER 16 CHAPTER 16: ENVIRONMENTAL ISSUES Air pollution and its control; water pollution and its control; agro chemicals and their effects; solid waste management; radioactive waste management; green house effect and climate change; impact and mitigation ozone layer depletion; deforestation; any one case study as success story addressing environmental issue. ¶ Pollution:  Undesirable physical/chemical/biological characteristics of air/ water/ land which cause damage to the animals/plants/humans and architectural structures. ¶ Pollutants: Agents which cause pollution. ¶ Slash and Burn Agriculture (Jhum Cultivation): Farmers cut down trees and burn the plant remains. Ash is used as a fertilizer and the land is then used for farming or cattle grazing. ¶ Reforestation:  Process of restoring a forest that was removed at some point of time in the past. ¶ Effluents: Something flowing over a large body of water (may be sewage or i...

REVISION NOTES FOR CBSE CLASS 12 BIOLOGY CHAPTER 15 CHAPTER 15: BIODIVERSITY AND ITS CONSERVATION Concept of biodiversity; patterns of biodiversity; importance of biodiversity; loss of biodiversity; odiversity onservation; hotspots, endangered organisms, extinction, Red Data Book, biosphere reserves, national parks, sanctuaries and Ramsar sites. Biodiversity: Term coined by socio-biologist Edward Wilson and was also  used by Walter G Rosen for the diversity of life forms. Biodiversity refers to the sum total of diversity that exists at genetic, species and ecosystem level of biological organisation. Three inter-related levels of Biodiversity:   • Genetic diversity • Species diversity • Ecological diversity ¶ Genetic diversity: Diversity in the number and types of genes, as well as chromosomes present in different species and the variations in the genes and their alleles in the same species. It helps in speciation. ¶ Species diversity: Varieties in  number and...

REVISION NOTES FOR CBSE CLASS 12 BIOLOGY CHAPTER- 14 CHAPTER 14: ECOSYSTEM Ecosystems; Patterns, components; productivity and decomposition; energy flow; pyramids of number, biomass, energy; nutrient cycles (carbon and phosphorus); ecological succession; ecological services- carbon fixation, pollination, seed dispersal, oxygen release (in brief). Ecosystem: It is the basic functional unit of biosphere in which living organisms interact among themselves and with their surrounding physical environment. Stratification: Vertical distribution of different species occupying different levels in an ecosystem. Trees occupy top vertical strata, shrubs the second layer. and herbs the third layer and herbs/grasses occupy the bottom layers. Primary Production: Amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis. Gross Primary Productivity: Rate of production of organic matter during photosynthesis.  Net Primary Productivity: ...

REVISION NOTES FOR CBSE CLASS 12 BIOLOGY CHAPTER 13 CHAPTER 13: ORGANISMS AND POPULATIONS Organisms and environment Habitat and niche, population and ecological adaptations; population interactions mutualism, competition, predation, parasitism; population attributes - growth. birth rate and death rate, age distribution. Ecology: A branch of science that studies interactions among organisms and their physical environment. Ecology is basically concerned with four levels of biological organisation Organisms, population, communities and biomes.  Ramdeo Mishra is called as the Father of Ecology in India.  Organisms: Organisms form the basic unit of study in ecology. Species:  Organisms with similar features and the potential to interbreed.  among themselves and produce fertile offsprings constitute a species.  Populations: Population is a group of individuals of the same species. inhabiting in a given area. Interspecific competition for basic needs opera...

Revision Notes for CBSE Class 12 Biology, Short Key Notes for CBSE Books CBSE Class 12 Biology Revision Notes  Biology is an interesting subject, and the plus two Biology revision notes come in handy to prepare you well for the Class 12 exams. Class 12 Biology NCERT notes made by experts at Shikshaforall cover the latest CBSE curriculum, and these are the well researched CBSE notes that let students understand the topic clearly. Biology notes for Class 12 are beneficial for a quick review because the subject matter experts make these. Chapter wise Revision Notes for Class 12 Biology Unit6 - Reproduction 1. Reproduction in Organism. 2. Sexual Reproduction in Flowering Plants. 3. Human Reproduction. 4. Reproductive Health. Unit7 - Genetics and Evolution 5. Principles of Inheritance and Variation. 6. Molecular Basis Of Inheritance 7. Evolution Unit8 - Biology And Human Welfare 8. Human Health and Diseases 9. strategies for enhancement in food production 10. Microbes In Hum...

REVISION NOTES FOR CBSE CLASS 12 BIOLOGY CHAPTER 12 CHAPTER 12: BIOTECHNOLOGY AND ITS APPLICATION Application 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, bio piracy and patents. Biopesticides: Biological agents that are used to control weeds, insects and  other pests. cry Gene: The Bt toxins are coded by a gene named cry. cry  Protein: The insecticidal protein which is produced by Bacillus  thuringiensis. Green Revolution : Substantial increase in crop yields due to use of high yielding varieties, use of fertilisers and pesticides, improved agricultural practices etc. Genetically Modified Organisms (GMO): The organisms which have  altered genes in them. These are also known as transgenic organisms. e.g. Bt Cotton, Bt Corn, Transgenic rat, Transgenic cow-Rosie. Molecular Diagnosis: Refers to early detect...