Notes From Toppers
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)