🚀 RBSE Class 12 Biology: Complete Bilingual Notes
हिंदी और English दोनों में | Diagrams & Tables Included
इस लेख में RBSE Class 12 Biology के सभी अध्यायों के Short Notes, Diagrams और Important Tables दिए गए हैं। यह Last Minute Revision के लिए Perfect है।
Unit 6: Reproduction (जनन)
Chapter 1: Sexual Reproduction in Flowering Plants
पुष्पीय पौधों में लैंगिक जनन
पुष्पीय पौधों में लैंगिक जनन
- Flower (पुष्प): Reproductive structure of Angiosperms. Four whorls: Calyx, Corolla, Androecium (Male), Gynoecium (Female).
- Stamen (पुंकेसर): Consists of Filament and Anther. Anther is bilobed and dithecous (2-theca).
- Pollen Grain (परागकण): Male gametophyte. 2-celled stage: Generative cell and Vegetative cell. Outer layer Exine (Sporopollenin - hardest organic material), Inner layer Intine.
- Embryo Sac (भ्रूणकोश): Female gametophyte. 7-celled and 8-nucleate structure. 1 Egg cell, 2 Synergids, 3 Antipodal cells, 1 Central cell (2 Polar nuclei).
- Pollination (परागण): Transfer of pollen grains to stigma. Types: Autogamy (Self), Geitonogamy, Xenogamy (Cross).
- Double Fertilization (द्विनिषेचन): Unique to Angiosperms. 1. Syngamy: Sperm + Egg = Zygote (2n). 2. Triple Fusion: Sperm + 2 Polar nuclei = Primary Endosperm Nucleus (3n).
Fig: Structure of Mature Embryo Sac (7-celled, 8-nucleate)
🔥 Important: Sporopollenin (स्पोरोपोलेनिन) is the most resistant organic material. It can withstand high temperatures and strong acids.
Chapter 2: Human Reproduction
मानव जनन
मानव जनन
- Male Reproductive System: Testes (in Scrotum), Accessory ducts (Vasa efferentia, Epididymis, Vas deferens), Glands (Seminal vesicle, Prostate, Bulbourethral). Seminiferous tubules produce sperms. Leydig cells produce Testosterone.
- Female Reproductive System: Ovaries, Oviducts, Uterus, Cervix, Vagina. Fertilization site: Ampullary-Isthmic junction.
- Spermatogenesis: Formation of sperms from spermatogonia. Spermatogonia (2n) → Primary Spermatocyte (2n) → Secondary Spermatocyte (n) → Spermatids (n) → Spermatozoa.
- Oogenesis: Formation of ova. Oogonia (2n) → Primary Oocyte (2n) → Meiosis I arrests at Prophase I. Completes at puberty.
- Menstrual Cycle (मासिक चक्र): Avg 28 days. 1. Menstrual phase (1-5 days), 2. Follicular phase, 3. Ovulatory (14th day - LH Surge), 4. Luteal phase.
- Parturition (प्रसव): Childbirth. Triggered by neuroendocrine reflex. Oxytocin causes uterine contractions.
| Feature | Spermatogenesis (शुक्राणुजनन) | Oogenesis (अंडाणुजनन) |
|---|---|---|
| Occurs in | Testes (Seminiferous tubules) | Ovaries |
| Starts at | Puberty | Embryonic development stage |
| Product | 4 functional spermatozoa | 1 ovum + 3 polar bodies |
Chapter 3: Reproductive Health
प्रजनन स्वास्थ्य
प्रजनन स्वास्थ्य
- Amniocentesis: Fetal sex determination test (Illegal in India). Also detects chromosomal abnormalities.
- Contraceptives (गर्भनिरोधक):
- Natural: Periodic abstinence, Withdrawal, Lactational amenorrhea.
- Barrier: Condoms (Male/Female), Diaphragms.
- IUDs: CuT (Copper T) - Releases Cu ions toxic to sperms.
- Oral Pills: Progestogens/Estrogen. Saheli - Non-steroidal, once a week.
- MTP (Medical Termination of Pregnancy): Safe abortion. Legal up to 12 weeks. Between 12-20 weeks requires opinion of 2 doctors.
- ART (Assisted Reproductive Technologies): IVF (In-vitro Fertilization), ZIFT (Zygote Intra-fallopian Transfer), GIFT (Gamete Intra-fallopian Transfer).
Unit 7: Genetics and Evolution (आनुवंशिकी एवं विकास)
Chapter 4: Principles of Inheritance
वंशागति के सिद्धांत
वंशागति के सिद्धांत
- Mendel's Laws (मेंडल के नियम): 1. Law of Dominance. 2. Law of Segregation (Purity of gametes). 3. Law of Independent Assortment.
- Monohybrid Cross: Single trait cross. Phenotypic ratio 3:1, Genotypic ratio 1:2:1.
- Dihybrid Cross: Two traits cross. Phenotypic ratio 9:3:3:1.
- Incomplete Dominance: Neither allele is completely dominant. e.g., Snapdragon (Antirrhinum) - Red x White = Pink (Intermediate).
- Co-dominance: Both alleles express equally. e.g., ABO Blood Group (AB shows both A and B antigens).
- Chromosomal Disorders: Down's Syndrome: Trisomy 21 (47 chromosomes). Klinefelter's Syndrome: XXY. Turner's Syndrome: XO.
Chapter 5: Molecular Basis of Inheritance
वंशागति का आण्विक आधार
वंशागति का आण्विक आधार
- DNA (Deoxyribose Nucleic Acid): Genetic material. Polynucleotide chain. Sugar: Deoxyribose. Bases: Adenine (A), Guanine (G), Cytosine (C), Thymine (T).
- Double Helix Model: Watson & Crick (1953). Two strands antiparallel (5'→3' and 3'→5'). Hydrogen bonds: A=T (2), G≡C (3).
- Packaging of DNA: Histone proteins. Nucleosome: Histone octamer + DNA. Negatively charged DNA wrapped around +vely charged histones.
- Central Dogma: Flow of information. DNA → RNA → Protein (Francis Crick).
- Transcription (अनुलेखन): DNA → RNA. Enzyme: RNA Polymerase. Promoter, Structural gene, Terminator.
- Genetic Code: Triplet codon. Start codon: AUG (Methionine). Stop codons: UAA, UAG, UGA. Universal and Degenerate.
- Lac Operon: Regulation of gene expression in E. coli. Inducer: Lactose. Repressor protein produced by Regulator gene.
Fig: DNA Double Helix Structure (Antiparallel)
| Feature | DNA | RNA |
|---|---|---|
| Sugar | Deoxyribose | Ribose |
| Bases | A, G, C, T | A, G, C, U |
| Structure | Double stranded | Single stranded |
Chapter 6: Evolution (विकास)
- Origin of Life: Oparin & Haldane theory. Chemical evolution. Miller & Urey experiment created Amino acids.
- Evidences for Evolution: Homologous organs: Same structure, different function (Divergent evolution). Analogous organs: Different structure, same function (Convergent evolution).
- Darwin's Theory: Natural Selection. Variations, Struggle for existence, Survival of the fittest.
- Hardy-Weinberg Principle: Gene frequency remains constant. p + q = 1; p² + 2pq + q² = 1. Factors affecting: Gene flow, Genetic drift, Mutation, Natural selection.
Unit 8 & 9: Human Welfare & Biotechnology
Chapter 7-10: Quick Revision Points
- Immunity: Innate (Non-specific) and Acquired (Specific). Active immunity: Body produces antibodies (Vaccination). Passive immunity: Ready-made antibodies given.
- AIDS: HIV virus (Retrovirus). Attacks Helper T-cells (CD4). Transmission: Sexual contact, Blood, Mother to child.
- Microbes: Lactobacillus: Curd. Yeast: Bread/Wine. Penicillium: Antibiotic. Bt Cotton: Pest resistant.
- Biotechnology Tools: Restriction Enzymes: Molecular scissors (Cut DNA). PCR: Polymerase Chain Reaction (DNA amplification). Plasmid: Cloning vector.
- Gene Therapy: Treating genetic diseases by inserting functional genes. Example: ADA deficiency treatment using Lymphocytes.
Unit 10: Ecology (पारिस्थितिकी)
Chapter 11-13: Ecology & Biodiversity
- Ecosystem: Biotic + Abiotic components. Producers: Autotrophs. Consumers: Heterotrophs. Decomposers: Bacteria/Fungi.
- Energy Flow: Unidirectional. 10% Law: Only 10% energy transferred to next trophic level.
- Ecological Pyramids: Upright (Energy always). Inverted (Biomass in aquatic ecosystem).
- Biodiversity: Variety of life forms. Types: Genetic, Species, Ecological. Latitudinal gradient: Decreases from equator to poles.
- Conservation: In-situ: National Parks, Sanctuaries (Natural habitat). Ex-situ: Zoo, Seed banks (Outside habitat).
Fig: Upright Ecological Pyramid of Energy
All the Best! सफलता आपके कदम चूमे। ✨
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