Detailed Notes for Genetics and Evolution (Molecular Basis of Inheritance)

DNA Structure and Replication:

• Structure of DNA: Double helix model, base pairing (complementary base pairing), Chargaff’s rules
• DNA Replication: Semi-conservative replication, DNA polymerases, leading and lagging strands, unwinding of DNA, replication fork, Okazaki fragments, DNA ligase (Reference: NCERT Biology Class 12, Chapter 6 - Molecular Basis of Inheritance)

Transcription:

• Process of Transcription: RNA polymerase, transcription factors, formation of transcription bubble, elongation, termination, RNA processing (5’ capping, splicing, 3’ polyadenylation) (Reference: NCERT Biology Class 12, Chapter 6 - Molecular Basis of Inheritance)

Translation:

• Process of Translation: mRNA, tRNA, ribosomes, genetic code, amino acid activation, elongation, termination, protein folding, post-translational modifications (Reference: NCERT Biology Class 12, Chapter 6 - Molecular Basis of Inheritance)

Gene Expression:

• Regulation of Gene Expression: Operon model (lac operon), inducible and repressible genes, repressors, activators, enhancer sequences, silencers (Reference: NCERT Biology Class 12, Chapter 6 - Molecular Basis of Inheritance)

Mutation:

• Types of Mutations: Point mutations (substitutions, deletions, insertions), frameshift mutations, chromosomal aberrations (deletions, duplications, inversions, translocations)
• Causes of Mutations: Spontaneous (errors in replication, tautomerism, DNA damage by chemicals, radiation) and induced mutations
• Effects of Mutations: Silent mutations, neutral mutations, missense mutations, nonsense mutations, frameshift mutations (Reference: NCERT Biology Class 12, Chapter 7 - Evolution)

Genetic Recombination:

• Process of Genetic Recombination: Crossing over during meiosis, chiasmata, role in genetic diversity, recombination frequencies, gene mapping (Reference: NCERT Biology Class 12, Chapter 7 - Evolution)

Mendelian Genetics:

• Fundamental Principles: Law of segregation, law of independent assortment, dominant-recessive relationships, probability in genetics (Reference: NCERT Biology Class 12, Chapter 5 - Principles of Inheritance and Variation)

Extensions of Mendelian Genetics:

• Gene interactions: Complementary genes, supplementary genes, epistatic genes
• Multiple alleles: ABO blood group system, Rh blood group system
• Sex-linked inheritance: X-linked and Y-linked genes, hemophilia, color blindness
• Linkage and crossing over: Linkage maps, recombination frequencies (Reference: NCERT Biology Class 12, Chapter 5 - Principles of Inheritance and Variation)

Human Genetics:

• Human chromosomal disorders: Down syndrome, Turner syndrome, Klinefelter syndrome
• Karyotyping
• Pedigree analysis
• Genetic diseases: Single-gene disorders (cystic fibrosis, sickle cell anemia), chromosomal disorders, multifactorial disorders (diabetes, hypertension, cancer), cancer genetics
• Human Genome Project (Reference: NCERT Biology Class 12, Chapter 5 - Principles of Inheritance and Variation)

DNA Technology:

• Recombinant DNA technology -Restriction enzymes
• Plasmid vectors
• Gene cloning
• DNA sequencing -Polymerase chain reaction (PCR)
• Applications in biotechnology and medicine (Reference: NCERT Biology Class 12, Chapter 11 - Biotechnology: Principles and Processes)

Evolution:

• Biological evolution, evidence supporting evolution -Comparative anatomy -Fossil records -Molecular evidence (DNA, protein sequencing, phylogenetic trees)
• Biogeography -Mechanisms of evolution -Natural selection
• Genetic drift
• Gene flow -Mutation (Reference: NCERT Biology Class 12, Chapter 7 - Evolution)

Origin of Life:

• Theories and hypotheses: Miller-Urey experiment, RNA world hypothesis, hydrothermal vents theory, panspermia (Reference: NCERT Biology Class 12, Chapter 7 - Evolution)

Population Genetics and Hardy-Weinberg Equilibrium:

• Population genetics, allele frequencies, genotype frequencies
• Hardy-Weinberg equilibrium: Conditions, consequences, factors affecting equilibrium -Deviations from Hardy-Weinberg equilibrium: Mutation, selection, migration, genetic drift, non-random mating (Reference: NCERT Biology Class 12, Chapter 7 - Evolution)