[//]:

(Slides 1 to 10)

Genetics and Evolution- Molecular Basis of Inheritance

Slide 1

• Topic: Molecular Basis of Inheritance
• Introduction to genetics and evolution
• Importance of understanding molecular basis of inheritance
• Overview of the upcoming lecture

Slide 2

• DNA and RNA: Fundamental molecules of heredity
• Structure of DNA
  • Double helix
  • Complementary base pairing
• Structure of RNA
  • Single-stranded
  • Different types: mRNA, tRNA, rRNA

Slide 3

• Central dogma of molecular biology
• Genetic information flow
• DNA replication
  • Enzymes involved: DNA polymerase, helicase
• Transcription
  • RNA polymerase and initiation factors

Slide 4

• Transcription (contd.)
  • Elongation and termination signals
  • mRNA processing: capping, splicing, polyadenylation
• Translation
  • Ribosomes and the role of tRNA
  • Genetic code and codons

Slide 5

• Introduction to enzymes involved in DNA replication and repair
• DNA helicase: Unwinding the double helix
• DNA polymerase: Synthesizing the new DNA strand
• Primase: Synthesis of RNA primer

Slide 6

• DNA Ligase: Joining Okazaki fragments
• Topoisomerase: Preventing the formation of DNA knots
• DNA repair enzymes: Maintaining genome integrity
• Examples of DNA repair mechanisms: Base excision repair, nucleotide excision repair

Slide 7

• Gene expression and regulation
• Control of gene expression
• Transcriptional regulation: Promoters and regulatory factors
• Post-transcriptional regulation: mRNA stability and processing

Slide 8

• Translation regulation: Initiation factors and RNA-binding proteins
• Recap of molecular basis of inheritance
• Overview of the next section: Genetic variation and evolution

Slide 9

• Genetic variation: Importance and sources
• Mutations: Types and effects
• Gene flow: Introduction of genetic variation through migration
• Gene drift: Random changes in gene frequencies

Slide 10

• Natural selection: Key mechanism behind evolution
• Types of natural selection: Directional, stabilizing, and disruptive
• Adaptation: Process of natural selection favoring advantageous traits
• Examples of natural selection in action

Slide 11

• Genetic drift (contd.)
  • Bottleneck effect: Reduction in population size leading to loss of genetic variation
  • Founder effect: Small group of individuals establish a new population with limited genetic diversity
• Genetic variation and its role in evolution
• Importance of studying genetic variation for understanding biological processes

Slide 12

• Hardy-Weinberg principle
• Concept of equilibrium population genetics
• Conditions for equilibrium: No natural selection, mutation, migration, genetic drift, or non-random mating
• Equations for calculating genotype frequencies in a population
  • p + q = 1
  • p^2 + 2pq + q^2 = 1

Slide 13

• Applications of the Hardy-Weinberg principle
• Estimating allele frequencies in a population
• Testing for genetic equilibrium
• Evaluating the impact of evolutionary forces on populations
• Understanding patterns of genetic diseases and population genetics

Slide 14

• Microevolution and macroevolution
• Different scales of evolution
• Microevolution: Changes in allele frequencies within a population over time
• Macroevolution: Large-scale changes leading to the formation of new species
• Role of genetic variation and natural selection in both processes

Slide 15

• Adaptive radiation: Diversification of ancestral species into multiple specialized forms
• Convergent evolution: Unrelated species evolving similar traits due to similar environmental pressures
• Coevolution: Reciprocal evolutionary changes between interacting species
• Examples of adaptation in various organisms

Slide 16

• Genetic basis of evolution
• Gene pool: All the genes in a population
• Allele frequency: Proportion of a specific allele in a population
• Genetic variation measured by heterozygosity and polymorphism
• Role of genetic variation in natural selection and evolution

Slide 17

• Molecular clocks and evolutionary divergence
• Mutations and their accumulation over time
• Rate of mutation as a measure of evolutionary time
• Comparing DNA or protein sequences between species
• Estimating evolutionary relationships using molecular clock data

Slide 18

• Types of mutations and their effects on proteins
• Silent, missense, nonsense, frame-shift, and insertions/deletions
• Impact of mutations on protein structure and function
• Examples of genetic diseases caused by specific mutations

Slide 19

• Molecular techniques in studying evolution
• Polymerase chain reaction (PCR) and DNA sequencing
• Phylogenetic analysis based on molecular data
• Comparative genomics and transcriptomics
• Application of molecular techniques in conservation biology and biogeography

Slide 20

• Recap of the topics covered
• Importance of understanding the molecular basis of inheritance for biology
• Overview of genetics and evolution as fields of study
• Final remarks and questions from the audience

Slide 21

• Which enzymes helps in charging of tRNA?
  • Aminoacyl-tRNA synthetases: Enzymes responsible for attaching specific amino acids to tRNA molecules
  • There are 20 different aminoacyl-tRNA synthetases, each specific for a particular amino acid
  • Each aminoacyl-tRNA synthetase recognizes its corresponding amino acid and the appropriate tRNA molecule

Slide 22

• Transfer RNA (tRNA) structure and function
  • Cloverleaf secondary structure
  • Anticodon region: Complementary to mRNA codon during translation
  • Amino acid attachment site (3’ end): Covalently binds to specific amino acids
• Importance of tRNA in protein synthesis

Slide 23

• Overview of protein synthesis
  • Transcription: Synthesis of mRNA from DNA template
  • Translation: Synthesis of polypeptide chain using mRNA template and tRNA molecules
• Ribosomes: Protein-RNA complexes responsible for translation
  • Large and small subunits
  • Ribosomal RNA (rRNA) and ribosomal proteins

Slide 24

• Initiation of translation
  • mRNA binding to small ribosomal subunit
  • Initiation factors facilitate the assembly of the initiation complex
  • Start codon recognition (AUG)
• Elongation and termination of translation
  • Addition of amino acids to the growing polypeptide chain
  • Stop codon recognition and release of the completed polypeptide chain

Slide 25

• Ribosome recycling and post-translational modifications
  • Release factors facilitate termination and ribosome recycling
  • Polypeptide folding, modifications, and targeting
  • Examples of post-translational modifications: phosphorylation, glycosylation

Slide 26

• Central dogma: DNA → RNA → Protein
• Gene expression regulation at multiple levels
  • Transcriptional regulation: control of gene expression during transcription
  • Post-transcriptional regulation: control of mRNA stability and processing
  • Translational regulation: control of protein synthesis during translation

Slide 27

• Transcriptional regulation
  • Promoters: DNA sequences where RNA polymerase binds to initiate transcription
  • Regulatory factors: Proteins that either enhance or repress transcription
  • Examples of regulatory factors: transcription factors, enhancers, repressors

Slide 28

• Post-transcriptional regulation
  • mRNA stability: regulated by factors that affect degradation rates
  • RNA processing: alternative splicing of exons to generate different mRNA isoforms
  • mRNA transport: localization of mRNA to specific cellular compartments

Slide 29

• Translational regulation
  • Initiation factors: regulate the assembly and activation of the translation machinery
  • RNA-binding proteins: bind to mRNA and influence its translation efficiency
  • Examples of translational regulation mechanisms: miRNA-mediated silencing, riboswitches

Slide 30

• Genetic variation and evolution summary
  • Importance of understanding the molecular basis of inheritance
  • Introduction to genetic variation and its sources
  • Mechanisms of evolution including natural selection and genetic drift
  • Role of molecular clocks in estimating evolutionary divergence
  • Applications of molecular techniques in studying evolution