MODULE 1 CONCEPTS & ITS APPLICATION

• Heredity


  Transmission of traits from one generation to another
• Gene


  The fundamental physical unit of heredity, whose existence can be confirmed by allelic variants and which occupies a specific chromosomal locus. A DNA sequence coding for a single polypeptide
• Allele


  One of the possible alternative forms of a gene, often distinguished from other alleles by phenotypic effects
• Homozygous


  When the two alleles are the same
• Heterozygous


  When the two alleles are different, the dominant allele is expressed
• Dominant


  A term applied to the trait (allele) that is expressed
• Recessive


  A term applied to a trait that is only expressed when the second allele is the same
• Genome


  The set of hereditary information encoded in the DNA of an organism, including both the protein-coding and non–protein-coding sequences
• Genotype


  The allelic or genetic constitution of an organism; often, the allelic composition of one or a limited number of genes under investigation
• Phenotype


  The overt appearance of a genetically controlled trait
• Subdisciplines in genetics


  • Behavioral genetics
  • Classical genetics
  • Cytogenetics
  • Developmental genetics
  • Ecological genetics
  • Genetic engineering
  • Genomics
  • Microbial genetics
  • Molecular genetics
  • Population genetics
• Behavioral genetics


  • Studies the genetic source of certain actions and behaviors in organisms. An example is the focus on twins and their different habits
• Classical genetics


  • The first of all genetic studies, focusing on visible characteristics that are passed down from parent to offspring. Gregor Mendel was made famous for his study of heredity in pea plants that shaped our understanding of genetics today
• Cytogenetics


  • Chromosomes, the containers for DNA and the code for genetic transfer, are studied in cytogenetics. Cytogenetics blends cytology, the study of cell structure, with genetics
• Developmental genetics


  • Studies how an organism forms from a single or multicellular origin upon fertilization to a fully formed organism. Some studies focus on the stem cell, an important cell that can differentiate into specialized cells and that is used frequently in medical research
• Ecological genetics


  • Shies away from laboratory settings and studies organisms in their natural habitats. This branch focuses on observable traits that are important in an organism's survival and life, such as the colors of feathers on a bird or the size of their beaks
• Genetic engineering


  • The manipulation of an organism's genome, changes or adds genes to an organism's sequence of DNA in order to create new traits or remove unwanted ones. It is used on many food products and animals and will likely be used on humans in the near future
• Genomics


  • The study of genomes, allows for evolutionary comparison between organisms and a broad study of genes and genetic interactions. It is one of the most-popular studies in modern genetic research
• Microbial genetics


  • Until recently, microorganisms were unstudied because of their small size, but advances in technology have allowed the study of microbial genetics to blossom into a revolutionary branch of the science
• Molecular genetics


  • Studies the individual molecular chemical properties of cells at a small scale, looking at, among other things, the molecular structure of DNA
• Population genetics


  • Focuses on the genetic differences in organisms within the same group or population
• Applied genetics


  • Agriculture
  • Medicine
  • Human development
• Agriculture


  • Applies genetic techniques to improve plants and animals. Breeding analysis and transgenic modification using recombinant DNA techniques are routinely used. Animal breeders use artificial insemination and hormone treatment to propagate desirable genes. Several types of mammals can be cloned
• Medicine


  • Genetic techniques are used to diagnose and treat inherited human disorders. Knowledge of family history may indicate hereditary tendencies. Genetic abnormalities can be detected in embryos. Gene therapy modifies defective genotypes by adding functional genes
• Human development


  • Developmental genetics studies how genes control the growth and development of an organism throughout its life-cycle. Heredity and genes play an important role in the transmission of physical and social characteristics from parents to offspring
• Model organisms used to study human diseases

  • E. coli
  • S. cerevisiae
  • D. melanogaster
  • C. elegans
  • D. rerio
  • M. musculus
• Mendel's work on pea plants established the basic principles of genetics, showing how traits are passed from parents to offspring
• Genes and chromosomes are the core units in the chromosomal theory of inheritance, which explains how genes on chromosomes control inherited traits and ensure genetic continuity across generations
• Molecular genetics, based on the idea that DNA makes RNA, which then makes proteins, explains the mechanisms of Mendelian genetics, also known as transmission genetics
• Recombinant DNA technology in molecular genetics allows genes from one organism to be inserted into vectors and cloned, creating many copies of specific DNA sequences
• Biotechnology has transformed agriculture, pharmaceuticals, and medicine by enabling mass production of important gene products, genetic testing for disorders, and potential gene therapy treatments
• Fields like genomics, proteomics, and bioinformatics, which emerged from recombinant DNA technology, combine genetics with IT to study genome sequences, gene functions, protein sets in cells, and genome evolution. The Human Genome Project is a key example
• Using model organisms has advanced genetic research and, with recombinant DNA technology, has helped create models for human genetic diseases
• Genetic technology has significant societal impacts, but policy and legislation have not kept pace with technological advancements