Lesson 1 Introduction to Genetics.pdf

Introduction to GENETICS LEO ART DIOSEP E. BORRES, MA Chair, Math and Sciences Department Albinism ©GMA News Albinism Albinism  Genetics Deals with the principles of heredity and variation in all living things Gk. “gen” –to become/to grow into something...

Introduction to GENETICS LEO ART DIOSEP E. BORRES, MA Chair, Math and Sciences Department Albinism ©GMA News Albinism Albinism  Genetics Deals with the principles of heredity and variation in all living things Gk. “gen” –to become/to grow into something Coined by William Bateson (1906) ©Ronnie Dadivas  Genetics scientific study of genes and heredity—of how certain qualities or traits are passed from parents to offspring as a result of changes in DNA sequence.  Genes A gene is a length of DNA that codes for a specific protein. For example, one gene will code for the protein insulin, which controls the amount of glucose in your bloodstream Genes are the units of heredity.  Genes Genes influence our lives Genes contribute to personality Genes are fundamental to who and what we are Genes  DNA Genes are made of a chemical called DNA, which is short for 'deoxyribonucleic acid'. constitutes the genetic material  Genome A genome is a complete set of genetic instructions for any organism. In humans, the genome consists of 23 pairs of chromosomes located in the cell’s nucleus, as well as a small chromosome in the cell’s mitochondria. A genome contains all the information needed for an individual to develop and function.  Division of Genetics Transmission genetics – classical genetics; examines the principles of heredity Molecular genetics - deals with the gene and the cellular processes by which genetic information is transferred and expressed Population genetics - concerns the genetic composition of groups of organisms and how that composition changes over time and space.  Humans Have Been Using Genetics for Thousands of Years 1. 10,000–12,000 years ago: domestication of plants and animals in the Middle East 2. 4,000 years ago: Assyrians and Babylonians developed several hundred varieties of date palms  Humans Have Been Using Genetics for Thousands of Years Ancient Greeks: theories of inheritance Pangenesis - Genetic information travels from different parts of the body to reproductive organs; incorrect. Inheritance of Acquired Characteristics -acquired traits become incorporated into hereditary characteristics information; Incorrect.  Humans Have Been Using Genetics for Thousands of Years 1. 17th Century: Preformationism Miniature organism resides in sex cells; thus all traits are inherited from one parent; Incorrect 2. Blending Theory Genes blend and mix. Incorrect  The Rise of the Science of Genetics 1860s: Gregor Mendel Founder of modern genetics began to experiment with crossing plants and creating hybrids. Discovered the basic principles of heredity.  The Rise of the Science of Genetics Developments in cytology (the study of cells) in the 1800s had a strong influence on genetics. 1839 - Matthias Jacob Schleiden and Theodor Schwann (1810–1882) proposed the cell theory 1879 – Walther Flemming observed the division of chromosomes and published a superb description of mitosis. 1885 - Biologists recognized that the cell nucleus contains the hereditary information  The Rise of the Science of Genetics 1859: Charles Darwin put forth the theory of evolution through natural selection and published his ideas in On the Origin of Species. August Weismann proposed the germ-plasm theory. The Rise of the Science of Genetics  The Rise of the Science of Genetics 1900s – turning point in the history of Genetics Gregor Mendel’s experiments with pea plants which revealed the principles of heredity, was rediscovered. 1902: Walter Sutton proposed that genes are located on chromosomes. 1910: Thomas Hunt Morgan discovered the first genetic mutant of fruit flies and used fruit flies to unravel many details of transmission genetics. 1930s: Geneticists began to integrate Mendelian genetics and evolutionary theory, establishing the foundation for population genetics.  The Rise of the Science of Genetics 1940s: Geneticists began to use bacteria and viruses DNA was found to be the repository of genetic information. 1953 - Era of molecular genetics: James Watson and Francis Crick, along with Maurice Wilkins and Rosalind Franklin, described the 3D structure of DNA.  The Rise of the Science of Genetics 1966: the chemical structure of DNA and the system by which it determines the amino acid sequence of proteins had been worked out. 1973: Advances in molecular genetics led to the first recombinant DNA experiments. 1977: Methods for rapidly sequencing DNA were first developed 1983: polymerase chain reaction (PCR) was developed by Kary Mullis and others.  The Rise of the Science of Genetics 1990: the Human Genome Project was launched. 1995: the first complete DNA sequence of a free- living organism—the bacterium Haemophilus influenza —was determined 1996: the first complete sequence of a eukaryotic organism (yeast) was reported. 2003: the human genome sequence was essentially completed, ushering a new era in genetics.  Model Genetic Organisms Model genetic organisms are organisms with characteristics that make them useful for genetic analysis. Six have been the most intensively studied genetically  Common Characteristics of Model Organisms Short generation time Production of numerous progeny The ability to carry out controlled genetic crosses The ability to be reared in a laboratory environment The availability of numerous genetic variants An accumulated body of knowledge about their genetic systems  Genetics Is Important to Individuals, to Society, and to the Study of Biology Genes are important in agriculture  Genetics Is Important to Individuals, to Society, and to the Study of Biology Genetics and Forensic Science  Genetics Is Important to Individuals, to Society, and to the Study of Biology Genes are important in biotechnology and medicine  Genetics Is Important to Individuals, to Society, and to the Study of Biology Genes are important in biotechnology and medicine