Biology notes Class 12

Class 12^th biology is very-very important for qualifying NEET exam with good rank and securing UG Medical seat in a government medical college. So it is very much essential to have biology notes for class 12th and these notes should cover important topics of the chapters keeping in mind the thought of PMT exams.

In this article we are going to explore all the16 chapters of biology and mentioning along with topics important questions for AIIMS, NEET, JIPMER examination PMT examinations.

CBSE Class 12 Biology Notes for All Chapters

Biology is the most interesting and scoring subject which is having full of amazing facts and exclusive discoveries. Biology is also one of the vital subjects in the science stream and obtaining good marks in this subject that could help students in placement in good medical institutions and others. As it's important to score a good percentage in the exams, it's not enough to study from the Class 12 textbook.

Students need some effective study materials and study tools like CBSE Notes for Class 12 Biology. So, to help them, we have already compiled the CBSE Class 12 Biology Notes for all the chapter.

• Chapter 1 - Reproduction in Organism

1. Asexual Reproduction
2. Important point - Zoospores, Conidia, Buds, Gemmules formation.
3. Vegetative Propagules.
4. Sexual Reproduction - Isogametes, Chromosomes in meiocytes of different organism given in NCERT table no.1.1

• Chapter 2 - Sexual Reproduction in Flowering Plants

1. Structure of Microsporangium, Tapetum, Microsporogenesis, sporopollenin, Pollen grains are shed (3-celled stage)
2. The Megasporangium (Ovule), Megasporogenesis, 8-nucleate stages of the embryo sac
3. Kinds of Pollination - Autogamy, Chasmogamous, cleistogamous flowers, Xenogamy
4. Double Fertilisation

• Chapter 3 - Human Reproduction

1. Male Reproductive System - Testicular lobules, Interstitial cells or Leydig cells, urethral meatus, Bulbourethral glands
2. Female Reproductive System - Perimetrium, Myometrium, Endometrium Mons pubis, Hymen, clitoris, Diagram of male reproductive , Female reproductive system GAMETOGENESIS in male , Female, Menstrual cycle, various events during a menstrual cycle, foetal ejection reflex, lactation, colostrum

• Chapter 4 - Reproductive Health

1. Amniocentesis, Periodic abstinence, Lactational amenorrhea , Intra Uterine Devices (IUDs).
2. Saheli, Medical termination of pregnancy (MTP), ZIFT, GIFT, ICSI, IUI

• Chapter 5 - Principle of Inheritance and Variations

1. Law of Segregation, factors, Co-dominance, Genetic Basis of Blood Groups in Human Population, Chromosomal Theory of Inheritance, Independent assortment of chromosomes
2. Linkage, X body, female heterogamety, male heterogamety, Haemophilia, Sickle-cell, Down’s Syndrome, Aneuploidy, Phenylketonuria, Anaemia

• Chapter 6 - Molecular Basis of Inheritance

1. 174 has 5386 nucleotides, Bacteriophage lambda has 48502 base pairs, Nucleosome, Hershey-Chase experiment, Histone octamer, Semiconservative DNA replication, Messelson and Stahl’s Experiment, Transcription Unit, DNA-dependent RNA polymerase,, Monocistronic, Polycistronic, Initiation-factor (σ), Termination-factor (ρ), Process of Transcription in Eukaryotes, Frame-shift insertion or deletion mutations, regulation of gene expression, Lac operon, Expressed Sequence Tags (ESTs), SNPs, repetitive DNA
2. DNA Finger Printing

• Chapter 7 - Evolution

1. Evidences of Evolution - Divergent evolution, Convergent evolution
2. Example of homologous organs in (a) Plants and (b) Animals
3. Adaptive radiation of marsupials of Australia, convergent evolution of Australian Marsupials and Placental mammals, HARDY-WEINBERG PRINCIPLE, Natural selection on different traits : (a) Stabilising (b) Directional and (c) Disruptive
4. Mechanism Evolution, saltation, Figure 7.9 A sketch of the evolution of plant forms through geological periods of NCERT, human evolution

• Chapter 8 - Human Heath and Disease

1. Typhoid, Widal test, Figure 8.1 Stages in the life cycle of Plasmodium, Amoebiasis, Amoebic dysentery, Immunity (i) Innate immunity and (ii) Acquired immunity, Cytokine barriers
2. Cell-mediated immunity (CMI)
3. Allergy, Auto-immune disease, Contact inhibition, alignant tumors
4. viral oncogenes, -interferon, Opioids, Cannabinoids , Withdrawal syndrome, cirrhosis

• Chapter 9 - Strategies for Enhancement in Food Production

1. Inbreeding depression. Interspecific hybridisation, Multiple Ovulation Embryo Transfer Technology (MOET) , Apiculture, Plant Breeding for Disease Resistance
2. Crop varieties for disease resistance to fungi, bacteria and viral diseases are released (Table 9.1) Mutation breeding, insect pest resistance are given in Table 9.2, Biofortification
3. Single Cell Protein (SCP), Totipotency, Micropropagation, Somaclones, Somatic hybridisation

• Chapter 10 - Microbes in Human Welfare

1. Bioactive Molecules, Examples of acid producers , MICROBES IN SEWAGE TREATMENT, Primary treatment, Secondary treatment or Biological treatment
2. BOD -biochemical oxygen demand, activated sludge, Biological control of pests and diseases
3. Bt-cotton, MICROBES AS BIOFERTILISERS, mycorrhiza

• Chapter 11 - Biotechnology: Principles and Processes

1. Restriction Enzymes, Recognition sequence for Hind II, Exonucleases and endonucleases
2. Palindromic nucleotide sequences, Gel electrophoresis, Cloning Vectors E. coli cloning vector pBR322 showing restriction sites (Hind III, EcoR I, BamH I, Sal I, Pvu II, Pst I, Cla I), Ori and Antibiotic resistance genes (ampR and tetR). Rop codes for the Proteins involved in the replication of the plasmid.
3. Insertional inactivation Vectors for cloning genes in plants and animals Competent Host (For Transformation with Recombinant DNA), Micro-injection Biolistics or Gene gun
4. Figure 11.6 Polymerase chain reaction (PCR) : Each cycle has three steps: (i) Denaturation; (ii) Primer annealing; and (iii) Extension of primers recombinant protein

• Chapter 12 - Biotechnology and its Applications

Genetically Modified Organisms (GMO), insecticidal protein, Pest Resistant Plants: RNA interference (RNAi). BIOTECHNOLOGICAL APPLICATIONS IN MEDICINE 3 Maturation of pro-insulin into insulin after removal of C peptide, adenosine deaminase (ADA) deficiency. Biopiracy

• Chapter 13 - Organism and Populations

Major Abiotic Factors, Figure 13.3 Diagrammatic representation of organismic response population density, Nt+1 = Nt + [(B + I) (D + E)], Figure 13.5 Population growth curve a when responses are not limiting the growth, plot is exponential, b when responses are limiting the growth, plot is logistic, K is carrying capacity, Logistic growth, Table 13.1  Population Interactions, Gause’s ‘Competitive Exclusion Principle’

• Chapter 14 - Ecosystem

1. Stratification, Net primary productivity (NPP). GPP R = NPP, Secondary productivity photosynthetically active radiation, detritus food chain (DFC), food web, Figure 14.2 Diagrammatic representation of trophic levels in an ecosystem, climax community ecological succession.
2. Hydrarch succession, Xerarch succession, Pioneer species, NUTRIENT CYCLING
3. Ecosystem - Phosphorus Cycle, Ecosystem services

• Chapter 15 - Biodiversity and Conservation

Figure 15.2 Showing species area relationship. Note that on log scale the relationship becomes linear, In situ conservation, Ex situ Conservation

• Chapter 16 - Enviornmental Issues

1. Environment (Protection) Act, 1986
2. Electrostatic precipitator, Compressed natural gas (CNG
3. Air (Prevention and Control of Pollution) Eutrophication, electronic wastes (e-wastes)
4. Green House Effect and Global Warming, Dobson units, Montreal Protocol, Chipko Movement

Frequently Asked Questions (FAQs)

Q1. What are ‘Single cell proteins'?

Ans. The proteins that are derived from the cells of microorganisms like yeast, fungi, algae and bacteria are called single-cell proteins.

Q2. What is meant by F1 and F2 generation?

Ans. F1: It's the primary filial generation obtained by crossing 2 different parents. F2: It's the second filial generation obtained by self-crossing the F1 generation.

Q3. What is meant of ‘genetic drift’?