GEN 3000 Notes Set 1 01 08 2016 Dr Tsai Clemson University Chapters 1 and 2 Chapter1 Genetics Note definitions are separated by semicolons The experimental Science of Heredity The study of heredity and the variation of inherited characteristics the branch of biology that deals with heredity especially the mechanisms of hereditary transmission and the variation of inherited characteristics among similar or related organisms The study of the patterns of inheritance of specific traits relating to genes and genetic information also known as heredity All of these definitions include the idea of heredity In this genetics class there are 3 sectors forms we will look at Transmission Genetics Mendel s work peas generational genetics Genetic information passed from one generation to the next Molecular Genetics The fine details within the big picture The why and how Involves DNA Replication transcription translation RNA protein creation This process is the central idea Population Genetics Genetics on a broader scale that spans multiple generations of a population This is especially relevant in the work of Darwin and theories of evolution Why is it important Modern Society depends on genetics and the use of the science of genetics for fuel fiber food medicine biotechnology and more It is the basis of the study of genetic diseases susceptibility and resistance family history and targeted medicines for specific genomes Dwarfism muscular dystrophy and other disorders are heavily gene linked On top of that the industry of healthcare is an enormous part of the US economy resulting in about 2 trillion per year which breaks down to 8608 per person in that year This is about 17 9 of the GDP As a fun fact hemophilia a clotting disorder inability to clot properly nicknamed The Royal Disease was historically found in the royalty of Europe and is sometimes even attributed to the collapse of the monarchy at that time Model Organisms Used in Genetic Studies E coli used to study colon cancer and other cancers S Cerevisiae used to study cancer and Werner Syndrome D melanogaster used to study disorders of the nervous system as well as cancer C elegans used to study diabetes D rerio used to study cardiovascular disease M musculus used to study Lesch Nyhan disease cystic fibrosis fragile X syndrome among others Canis lupus familaris Aka the dog used to study genetics in general Genetics Through History We re not really sure when humans started questioning the idea of WHY things happen across generations Historically we can see that some domestication principles of heredity was first demonstrated 10 12 000 years ago Artificial fertilization was seen 2880 years ago And Hindu writings 2000 years ago suggested avoiding spouses with undesirable traits considering they noticed a trend of heredity 8000 1000 BC domestication of animals began in earnest but there wasn t as much going on in the realm of genetics The 1600s was when the majority of hypotheses and theories began to show up Then the 1800s Darwin and Mendel revolutionized the way humans looked at genes Original Theories A couple of concepts took hold originally Pangenesis Specific particles called gemmules carry information from the body to reproduce organs which are passed to embryo at conception Needless to say this fell out of favor At this time sperm and egg hadn t been visualized but the concept of gemmules was similar to gametes The term gene did however come from this early theory This idea led to the idea of inheritance of acquired characteristics the idea also was that learned skills would be passed onto the next generation artist passes on artistic knowledge to children Robert Hooke in 1665 discovered a cell using a microscope The invention and use of the microscope to see cells and thus gametes led to the idea of Preformationism The idea that inside egg or sperm is a tiny version of an adult this tiny person was called a homunculus Fertilization allows it to grow and develop Originally the homunculus was thought to be in the sperm then maybe in the egg Then the idea of blending inheritance was born suggesting that offspring are a blend of parents Schleiden and Schwann came up with the cell theory and proposed it in 1839 cells are the basic unit of all living things and they divide and arise from preexisting cells even on the single cellular level Never just a sudden appearance of an organism In the 1850 s Darwin published his work He lived from 1809 1882 He developed the theory of evolution through natural selection His published work was On the Origin of Species 1856 heredity was the fundamental of evolution and created the idea that evolution and natural selection are based on the passing of genes However at this time people didn t understand what was happening on an individual level let alone a population level devaluing his work at the time Gregor Mendel was working about the same time as Darwin 1822 1884 Discovered basic principles of heredity 1866 However this work went largely ignored until the 1900s He crossed pea plants and analyzed patters of transmission Walter Flemming observed the division of chromosomes 1879 Then it was discovered in 1885 that hereditary information is contained in the nucleus August Weismann The idea of inheritance of acquired characteristics was hard put to die out So Weismann experimented by cutting off the tails of mice for 22 generations This showed that tail length did not change in subsequent generations The germ plasm theory was then developed which suggested cells of the reproductive system carry complete sets of information The idea that the sperm and egg carry preexisting information It wasn t until the mid 1900s that we see a lot of progression in genetics which is when we realize that Mendel s work is correct We went from the beginning of 1900s showing that genes are on chromosomes to 2003 when the entire human genome is defined Chapter 2 Chromosomes and Cellular Reproduction Mitosis Meiosis Prokaryote Has a cell wall and a plasma membrane contains ribosomes and DNA Tend to be small and less complex Contain no membrane bound nucleus It includes the classifications of eubacterium and the archaebacterium Archaebacterium contain characteristics of bacteria and eukaryotes Eubacteria true bacteria Eukaryotes Has a nucleus and is relatively large and complex with multiple linear DNA molecules Contain membrane bound organelles and a cytoskeleton There are 3 major groups of life eubacteria archaea eukaryotes