SCERT Kerala lessons

ORIGINAL STUDY COMPANION PADIKAM CLASS 12 | SCIENCE Biology Kerala SCERT / prescribed NCERT core lessons 14 chapter lessons Quick explanations, core points, exam practice and chapter-specific notation in one consistent format. Padikam explanations are independently written. Official textbooks are used as the coverage map, chapter sequence and terminology reference. PADIKAM | KERALA CLASS 12 1

Contents 01 Sexual Reproduction in Flowering Plants 08 Microbes in Human Welfare 02 Human Reproduction 09 Biotechnology: Principles and Processes 03 Reproductive Health 10 Biotechnology and Its Applications 04 Principles of Inheritance and Variation 11 Organisms and Populations 05 Molecular Basis of Inheritance 12 Ecosystem 06 Evolution 13 Biodiversity and Conservation 07 Human Health and Disease 14 Formative Reading: Environmental Issues Study rhythm Read the quick explanation, recall the core points aloud, then answer the prompts without looking back. Use the official textbook links for full prescribed readings, activities and diagrams. Textbook and verification links

1. https://www.hsslive.in/2015/05/plus-two-2-new-text-booksscert.html
2. https://samagra.kite.kerala.gov.in/
3. https://ncert.nic.in/textbook.php
4. https://ncert.nic.in/textbook.php?lebo1=0-13 PADIKAM | KERALA CLASS 12 2

CHAPTER 01 Sexual Reproduction in Flowering Plants Quick understanding Flowering plants form gametophytes, transfer pollen, complete double fertilisation and develop seeds and fruits. Core points Check your learning Anther and ovule development produce male and Explain the central idea of Sexual female gametophytes. Reproduction in Flowering Plants in your own words. Pollen-pistil interaction controls compatible fertilisation. Apply one idea from Sexual Reproduction in Flowering Plants to a Double fertilisation forms both zygote and primary textbook-style example or source. endosperm nucleus. One-line recall Anther and ovule development produce male and female gametophytes. PADIKAM | KERALA CLASS 12 3

CHAPTER 02 Human Reproduction Quick understanding Human reproduction coordinates anatomy, gamete formation, hormonal cycles, fertilisation, implantation and birth. Core points Check your learning Spermatogenesis and oogenesis differ in timing and Explain the central idea of Human products. Reproduction in your own words. The menstrual cycle reflects ovarian and uterine Apply one idea from Human hormone changes. Reproduction to a textbook-style example or source. Placenta supports exchange and also acts as an endocrine tissue. One-line recall Spermatogenesis and oogenesis differ in timing and products. PADIKAM | KERALA CLASS 12 4

CHAPTER 03 Reproductive Health Quick understanding Reproductive health combines informed choice, disease prevention, safe care and responsible reproductive technologies. Core points Check your learning Contraceptive methods act at different stages. Explain the central idea of Reproductive Health in your own words. STI prevention depends on awareness, testing and barrier protection. Apply one idea from Reproductive Health to a textbook-style example or source. Assisted reproductive technologies address selected causes of infertility. One-line recall Contraceptive methods act at different stages. PADIKAM | KERALA CLASS 12 5

CHAPTER 04 Principles of Inheritance and Variation Quick understanding Inheritance patterns arise from allele behaviour, chromosome movement, linkage, recombination and mutation. Core points Check your learning Mendelian ratios require stated assumptions. Explain the central idea of Principles of Inheritance and Variation in your own Incomplete dominance and codominance do not words. destroy segregation. Apply one idea from Principles of Pedigrees and karyotypes reveal different kinds of Inheritance and Variation to a textbook- inherited conditions. style example or source. Equation and notation Monohybrid F₂ phenotypic ratio = 3:1 Hardy-Weinberg: p² + 2pq + q² = 1 SYMBOLS AND UNITS p, q: allele frequencies, dimensionless p², 2pq, q²: genotype frequencies, dimensionless One-line recall Mendelian ratios require stated assumptions. PADIKAM | KERALA CLASS 12 6

CHAPTER 05 Molecular Basis of Inheritance Quick understanding DNA stores sequence information that is replicated and expressed through RNA and protein synthesis. Core points Check your learning Semiconservative replication copies each parental Explain the central idea of Molecular strand. Basis of Inheritance in your own words. The genetic code is read in triplet codons. Apply one idea from Molecular Basis of Inheritance to a textbook-style example Regulation changes gene expression without or source. changing the basic code. One-line recall Semiconservative replication copies each parental strand. PADIKAM | KERALA CLASS 12 7

CHAPTER 06 Evolution Quick understanding Evolution explains population change across generations through variation, selection, drift, gene flow and shared ancestry. Core points Check your learning Evidence comes from fossils, anatomy, embryos and Explain the central idea of Evolution in molecules. your own words. Natural selection changes allele frequencies through Apply one idea from Evolution to a differential reproduction. textbook-style example or source. Hardy-Weinberg equilibrium provides a reference for detecting change. Equation and notation p + q = 1 p² + 2pq + q² = 1 SYMBOLS AND UNITS p, q: frequencies of two alleles All frequencies are dimensionless and range from 0 to 1 One-line recall Evidence comes from fossils, anatomy, embryos and molecules. PADIKAM | KERALA CLASS 12 8

CHAPTER 07 Human Health and Disease Quick understanding Health depends on host, pathogen, immunity, behaviour and environment, so prevention and treatment work at several levels. Core points Check your learning Innate and adaptive immunity have different speed Explain the central idea of Human Health and specificity. and Disease in your own words. Vaccination builds immunological memory. Apply one idea from Human Health and Disease to a textbook-style example or Cancer, HIV infection and substance misuse require source. accurate, non-stigmatising understanding. One-line recall Innate and adaptive immunity have different speed and specificity. PADIKAM | KERALA CLASS 12 9

CHAPTER 08 Microbes in Human Welfare Quick understanding Microorganisms support food production, industry, sewage treatment, energy, biological control and nutrient cycling. Core points Check your learning Fermentation products depend on organism and Explain the central idea of Microbes in conditions. Human Welfare in your own words. Activated sludge reduces organic load in sewage. Apply one idea from Microbes in Human Welfare to a textbook-style example or Biofertilisers and biocontrol can lower dependence source. on synthetic inputs. One-line recall Fermentation products depend on organism and conditions. PADIKAM | KERALA CLASS 12 10

CHAPTER 09 Biotechnology: Principles and Processes Quick understanding Modern biotechnology isolates, cuts, joins, transfers and selects genetic material using controlled biological tools. Core points Check your learning Restriction enzymes cut selected DNA sequences. Explain the central idea of Biotechnology: Principles and Processes Vectors carry inserts into host cells. in your own words. PCR amplifies a target sequence through repeated Apply one idea from Biotechnology: temperature cycles. Principles and Processes to a textbook- style example or source. One-line recall Restriction enzymes cut selected DNA sequences. PADIKAM | KERALA CLASS 12 11

CHAPTER 10 Biotechnology and Its Applications Quick understanding Biotechnology applies engineered organisms or molecules to medicine, agriculture and diagnosis while raising biosafety and ownership questions. Core points Check your learning Recombinant insulin separates production from Explain the central idea of Biotechnology animal extraction. and Its Applications in your own words. Bt crops express a microbial insecticidal protein. Apply one idea from Biotechnology and Its Applications to a textbook-style Patents, biopiracy and biosafety require ethical and example or source. legal scrutiny. One-line recall Recombinant insulin separates production from animal extraction. PADIKAM | KERALA CLASS 12 12

CHAPTER 11 Organisms and Populations Quick understanding Population ecology links organismal adaptations with birth, death, age structure, growth and species interactions. Core points Check your learning Population size changes through births, deaths, Explain the central idea of Organisms immigration and emigration. and Populations in your own words. Exponential and logistic models make different Apply one idea from Organisms and resource assumptions. Populations to a textbook-style example or source. Mutualism, competition, predation and parasitism shape communities. Equation and notation Exponential growth: dN/dt = rN Logistic growth: dN/dt = rN(1 - N/K) SYMBOLS AND UNITS N: population size t: time r: intrinsic rate of natural increase (time⁻¹) K: carrying capacity in number of individuals One-line recall Population size changes through births, deaths, immigration and emigration. PADIKAM | KERALA CLASS 12 13

CHAPTER 12 Ecosystem Quick understanding An ecosystem moves energy through trophic levels while cycling matter between organisms and the physical environment. Core points Check your learning Productivity measures biomass or energy production Explain the central idea of Ecosystem in per area per time. your own words. Decomposition includes fragmentation, leaching, Apply one idea from Ecosystem to a catabolism, humification and mineralisation. textbook-style example or source. Energy flow is one-way; nutrients cycle. Equation and notation NPP = GPP - R SYMBOLS AND UNITS NPP: net primary productivity (energy or mass area⁻¹ GPP: gross primary productivity time⁻¹) R: respiratory loss in matching units One-line recall Productivity measures biomass or energy production per area per time. PADIKAM | KERALA CLASS 12 14

CHAPTER 13 Biodiversity and Conservation Quick understanding Biodiversity at genetic, species and ecosystem levels supports resilience and human well-being but is threatened by rapid loss. Core points Check your learning Species richness follows broad latitudinal and area Explain the central idea of Biodiversity patterns. and Conservation in your own words. Habitat loss, overuse, invasion and co-extinction are Apply one idea from Biodiversity and major drivers. Conservation to a textbook-style example or source. In-situ conservation protects habitats; ex-situ conservation protects selected organisms. One-line recall Species richness follows broad latitudinal and area patterns. PADIKAM | KERALA CLASS 12 15

CHAPTER 14 Formative Reading: Environmental Issues Quick understanding Examine pollution, waste, climate change, ozone loss and land degradation through causes, effects and prevention. Core points Check your learning Prevention and reduction are preferred to end-of- Explain the central idea of Formative pipe treatment. Reading: Environmental Issues in your own words. Biomagnification increases selected persistent pollutants along food chains. Apply one idea from Formative Reading: Environmental Issues to a textbook-style Environmental decisions must connect evidence, law, example or source. technology and public participation. One-line recall Prevention and reduction are preferred to end-of-pipe treatment. PADIKAM | KERALA CLASS 12 16