1. Genetics and Evolution - Molecular Basis of Inheritance
  • Introduction to the topic: Molecular Basis of Inheritance
  • Definition: The study of how genetic information is stored, transferred, and expressed in living organisms
  • Importance: Understanding the molecular mechanisms of inheritance is crucial to understand genetic disorders, evolution, and biotechnology applications
  1. DNA and RNA: Building Blocks of Genetic Information
  • DNA (Deoxyribonucleic Acid) and RNA (Ribonucleic Acid)
  • Structure of DNA: Double helix, composed of nucleotides (phosphate, sugar, and nitrogenous base)
  • Types of RNA: Messenger RNA (mRNA), Transfer RNA (tRNA), Ribosomal RNA (rRNA)
  • Role of DNA and RNA: DNA stores genetic information, while RNA carries out protein synthesis
  1. Central Dogma of Molecular Biology
  • Central Dogma: The flow of genetic information from DNA to RNA to protein
  • DNA Replication: Process of DNA synthesis, ensures accurate transmission of genetic information during cell division
  • Transcription: DNA is used as a template to synthesize mRNA
  • Translation: mRNA is decoded by ribosomes to produce proteins
  1. Genetic Code
  • Genetic code: The set of rules which determine the translation of mRNA nucleotide sequence into amino acid sequence
  • Codons: Three-nucleotide sequences on mRNA that code for specific amino acids
  • Start codon: AUG (codes for methionine), initiates protein synthesis
  • Stop codons: UAA, UAG, UGA, signify the end of protein synthesis
  1. Protein Synthesis
  • Step 1: Transcription
    • Initiation: RNA polymerase binds to the promoter region of DNA
    • Elongation: RNA polymerase synthesizes mRNA using DNA as a template
    • Termination: RNA polymerase reaches the terminator sequence, mRNA is released
  • Step 2: Translation
    • Initiation: Ribosomes bind to mRNA at the start codon
    • Elongation: tRNA carries amino acids to the ribosome, forming a polypeptide chain
    • Termination: Ribosome encounters a stop codon, polypeptide is released
  1. Mutations: Changes in Genetic Information
  • Mutations: Changes in DNA sequence that can lead to genetic variability
  • Types of mutations: Point mutations, frameshift mutations, chromosomal mutations
  • Effects of mutations: Silent mutations, missense mutations, nonsense mutations
  • Impact of mutations: Can cause genetic disorders, contribute to evolution, or have no significant effect
  1. Recombinant DNA Technology
  • Recombinant DNA: DNA that is formed by combining DNA fragments from different sources
  • Techniques in recombinant DNA technology: Restriction enzymes, DNA ligation, Polymerase Chain Reaction (PCR)
  • Applications of recombinant DNA technology: Gene cloning, production of genetically modified organisms (GMOs), gene therapy
  1. Genomic Organization and Gene Expression Regulation
  • Genomic organization: The way genes are arranged on chromosomes
  • Prokaryotic gene expression regulation: Operon model (lac operon, trp operon)
  • Eukaryotic gene expression regulation: Enhancers, silencers, transcription factors, epigenetic modifications
  1. DNA Replication: The Molecular Basis of Heredity
  • DNA replication: Process by which a DNA molecule is copied to produce two identical DNA molecules
  • Steps of DNA replication: Initiation, elongation, termination
  • Enzymes involved in DNA replication: DNA helicase, DNA polymerase, DNA ligase
  • Significance of DNA replication: Ensures inheritance of genetic information during cell division
  1. Transcription and Translation: Gene Expression
  • Transcription: Process of synthesizing an mRNA molecule using DNA as a template
  • Translation: Process of decoding the mRNA molecule to synthesize proteins
  • Differences between transcription and translation: Location, involvement of different molecules, final product
  1. Genetics and Evolution - Molecular Basis of Inheritance - What are the functions of Cap
  • Introduction to Cap: Cap refers to the capped structure found at the 5’ end of eukaryotic mRNA
  • Functions of Cap:
    • Protection: Cap protects the mRNA from degradation by exonucleases
    • Ribosome binding: Cap helps in the binding of ribosomes to initiate translation
    • Enhancing mRNA stability: Cap contributes to the stability of mRNA molecules
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is Alternative Splicing?
  • Definition of Alternative Splicing: A process in which different combinations of exons are spliced together to generate multiple mRNA isoforms from a single gene
  • Importance of Alternative Splicing:
    • Increases proteome diversity: Allows for the production of different protein isoforms from a single gene
    • Regulation of gene expression: Alternative splicing can regulate the expression of certain genes by including or excluding specific exons
    • Functional diversity: Results in proteins with different functions or properties
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is a DNA Marker?
  • Definition of DNA Marker: A specific DNA sequence used to identify and locate genes or genetic variations in individuals or populations
  • Types of DNA markers:
    • Restriction Fragment Length Polymorphisms (RFLPs)
    • Microsatellites (Short Tandem Repeats, STRs)
    • Single Nucleotide Polymorphisms (SNPs)
  • Applications of DNA markers: Genetic mapping, forensic science, paternity testing, population genetics studies
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is Genetic Engineering?
  • Definition of Genetic Engineering: The manipulation of an organism’s genetic material to alter its characteristics or create new traits
  • Techniques in genetic engineering:
    • Recombinant DNA technology: Combining DNA from different sources
    • Gene editing: Modifying existing DNA sequences using CRISPR/Cas9 or other tools
  • Applications of genetic engineering: Agriculture, medicine, environmental remediation
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is DNA Fingerprinting?
  • Definition of DNA Fingerprinting: A technique used to identify and compare individuals based on their unique DNA profiles
  • Steps involved in DNA fingerprinting:
    • DNA extraction: Isolation of DNA from a biological sample (e.g. blood, saliva)
    • Polymerase Chain Reaction (PCR): Amplification of specific DNA regions
    • Gel Electrophoresis: Separation of DNA fragments based on size
    • DNA profiling: Comparison of DNA banding patterns to establish identity or relationships
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is Genetic Counseling?
  • Definition of Genetic Counseling: A process that helps individuals or families understand and adapt to the implications of a genetic disorder or genetic risk
  • Goals of genetic counseling:
    • Provide information and education about genetic conditions
    • Assess individual or family risk factors
    • Discuss options for testing, treatment, and reproductive choices
    • Offer emotional support and guidance for coping with genetic conditions
  1. Genetics and Evolution - Molecular Basis of Inheritance - What are the different patterns of inheritance?
  • Mendelian patterns of inheritance:
    • Autosomal dominant: Inheritance of a dominant allele on an autosome
    • Autosomal recessive: Inheritance of a recessive allele on an autosome
    • X-linked dominant: Inheritance of a dominant allele on the X chromosome
    • X-linked recessive: Inheritance of a recessive allele on the X chromosome
  • Non-Mendelian patterns of inheritance: Incomplete dominance, codominance, polygenic traits, multifactorial inheritance
  1. Genetics and Evolution - Molecular Basis of Inheritance - Example: Autosomal Dominant Inheritance
  • Definition of Autosomal Dominant Inheritance: Inheritance pattern where a single copy of the dominant allele is sufficient to cause the trait or disorder
  • Example: Huntington’s disease
    • Causative gene: HTT gene on chromosome 4
    • Symptoms: Progressive degeneration of brain cells, movement disorders, cognitive decline
    • Inheritance: Offspring of an affected parent have a 50% chance of inheriting the disease
  1. Genetics and Evolution - Molecular Basis of Inheritance - Example: Autosomal Recessive Inheritance
  • Definition of Autosomal Recessive Inheritance: Inheritance pattern where two copies of the recessive allele are required to manifest the trait or disorder
  • Example: Cystic fibrosis
    • Causative gene: CFTR gene on chromosome 7
    • Symptoms: Lung infections, digestive problems, salt imbalance
    • Inheritance: Offspring of carrier parents have a 25% chance of inheriting the disease
  1. Genetics and Evolution - Molecular Basis of Inheritance - Example: X-Linked Recessive Inheritance
  • Definition of X-Linked Recessive Inheritance: Inheritance pattern where the recessive allele is carried on the X chromosome
  • Example: Hemophilia
    • Causative genes: F8 gene (Hemophilia A) and F9 gene (Hemophilia B)
    • Symptoms: Impaired blood clotting, excessive bleeding
    • Inheritance: Sons of carrier mothers have a 50% chance of inheriting the disease, while daughters have a 50% chance of being carriers
  1. Genetics and Evolution - Molecular Basis of Inheritance - What are the functions of Cap
  • Definition of Cap: The capped structure found at the 5’ end of eukaryotic mRNA
  • Functions of Cap:
    • Protection: Cap protects the mRNA from degradation by exonucleases
    • Ribosome binding: Cap helps in the binding of ribosomes to initiate translation
    • Enhancing mRNA stability: Cap contributes to the stability of mRNA molecules
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is Alternative Splicing?
  • Definition of Alternative Splicing: A process in which different combinations of exons are spliced together to generate multiple mRNA isoforms from a single gene
  • Importance of Alternative Splicing:
    • Increases proteome diversity: Allows for the production of different protein isoforms from a single gene
    • Regulation of gene expression: Alternative splicing can regulate the expression of certain genes by including or excluding specific exons
    • Functional diversity: Results in proteins with different functions or properties
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is a DNA Marker?
  • Definition of DNA Marker: A specific DNA sequence used to identify and locate genes or genetic variations in individuals or populations
  • Types of DNA markers:
    • Restriction Fragment Length Polymorphisms (RFLPs)
    • Microsatellites (Short Tandem Repeats, STRs)
    • Single Nucleotide Polymorphisms (SNPs)
  • Applications of DNA markers: Genetic mapping, forensic science, paternity testing, population genetics studies
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is Genetic Engineering?
  • Definition of Genetic Engineering: The manipulation of an organism’s genetic material to alter its characteristics or create new traits
  • Techniques in genetic engineering:
    • Recombinant DNA technology: Combining DNA from different sources
    • Gene editing: Modifying existing DNA sequences using CRISPR/Cas9 or other tools
  • Applications of genetic engineering: Agriculture, medicine, environmental remediation
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is DNA Fingerprinting?
  • Definition of DNA Fingerprinting: A technique used to identify and compare individuals based on their unique DNA profiles
  • Steps involved in DNA fingerprinting:
    • DNA extraction: Isolation of DNA from a biological sample (e.g., blood, saliva)
    • Polymerase Chain Reaction (PCR): Amplification of specific DNA regions
    • Gel Electrophoresis: Separation of DNA fragments based on size
    • DNA profiling: Comparison of DNA banding patterns to establish identity or relationships
  1. Genetics and Evolution - Molecular Basis of Inheritance - What is Genetic Counseling?
  • Definition of Genetic Counseling: A process that helps individuals or families understand and adapt to the implications of a genetic disorder or genetic risk
  • Goals of genetic counseling:
    • Provide information and education about genetic conditions
    • Assess individual or family risk factors
    • Discuss options for testing, treatment, and reproductive choices
    • Offer emotional support and guidance for coping with genetic conditions
  1. Genetics and Evolution - Molecular Basis of Inheritance - What are the different patterns of inheritance?
  • Mendelian patterns of inheritance:
    • Autosomal dominant: Inheritance of a dominant allele on an autosome
    • Autosomal recessive: Inheritance of a recessive allele on an autosome
    • X-linked dominant: Inheritance of a dominant allele on the X chromosome
    • X-linked recessive: Inheritance of a recessive allele on the X chromosome
  • Non-Mendelian patterns of inheritance: Incomplete dominance, codominance, polygenic traits, multifactorial inheritance
  1. Genetics and Evolution - Molecular Basis of Inheritance - Example: Autosomal Dominant Inheritance
  • Definition of Autosomal Dominant Inheritance: Inheritance pattern where a single copy of the dominant allele is sufficient to cause the trait or disorder
  • Example: Huntington’s disease
    • Causative gene: HTT gene on chromosome 4
    • Symptoms: Progressive degeneration of brain cells, movement disorders, cognitive decline
    • Inheritance: Offspring of an affected parent have a 50% chance of inheriting the disease
  1. Genetics and Evolution - Molecular Basis of Inheritance - Example: Autosomal Recessive Inheritance
  • Definition of Autosomal Recessive Inheritance: Inheritance pattern where two copies of the recessive allele are required to manifest the trait or disorder
  • Example: Cystic fibrosis
    • Causative gene: CFTR gene on chromosome 7
    • Symptoms: Lung infections, digestive problems, salt imbalance
    • Inheritance: Offspring of carrier parents have a 25% chance of inheriting the disease
  1. Genetics and Evolution - Molecular Basis of Inheritance - Example: X-Linked Recessive Inheritance
  • Definition of X-Linked Recessive Inheritance: Inheritance pattern where the recessive allele is carried on the X chromosome
  • Example: Hemophilia
    • Causative genes: F8 gene (Hemophilia A) and F9 gene (Hemophilia B)
    • Symptoms: Impaired blood clotting, excessive bleeding
    • Inheritance: Sons of carrier mothers have a 50% chance of inheriting the disease, while daughters have a 50% chance of being carriers