chapter 1 notes .pdf

BIO Genetics Notes Chapter 1 Vocab examples Genetics: The specific study of heredity- how traits and diseases are passed from generation to generation & cellular gene function - Influences social, political, legal, and ethical institutions and policies Gene: string of nucleotides in a DNA mole...

BIO Genetics Notes Chapter 1 Vocab examples Genetics: The specific study of heredity- how traits and diseases are passed from generation to generation & cellular gene function - Influences social, political, legal, and ethical institutions and policies Gene: string of nucleotides in a DNA molecule - The unit of heredity - The structural and functional unit of genetics - Genes made of unique sequences of nucleotides in a DNA molecule - 4 nucleotides - Adenine (A) - Thymine (T) - Guanine (G) - Cytosine © DNA sequence: - The sequence of the nucleotides in a DNA molecule - Stores the genetic information of an individual - Defines which aas will be used to make specific proteins Genes are sequences of nucleotides in DNA 3D structure of a protein - Aas are made of polypeptide chains, which become functional proteins when folded into specific 3D shapes upon activation - The action of proteins produce traits - Nucleotide sequence (the letters) encoded in a gene defines the AAs that make up the gene products (proteins)  - When a gene gets activated its stored information is decoded to make a polypeptide which folds into a 3D shape turning it into a functional protein which then produces characteristics we can SEE or MEASURE Genes transmitted from parent to offspring - Mendel established the foundations of genetics Mendel’s Conclusions - Each parent carries 2 genes (gene pair) for a specific trait - Each parent contributes only one of those genes to its offspring - The 2 copies of a gene (from each parent) separate from each other during meiosis - @fertilization the genes from mom and dad become members of a new gene pair in the offspring Chromosomes: Genes contained on chromosomes in the nucleus of a eukaryotic cell The 4 ways scientists study genes - Transmission genetics: how genes are transferred from parent to next generation - Pattern of inheritance - EXAMPLE– mendel did transmission genetics using pea plants as his experimental organisms - Pedigree analysis: an indirect method to study the inheritance of humans by reconstructing the pattern of inheritance associated with a trait as it passes through generations to determine how a trait is inherited and to establish the risk of having affected children - Construction of family trees used to follow transmission (inheritance) of genetic traits in families - Males squares - Females circles - Shaded = affected - Each horizontal group is a new generation - Cytogenetics: using microscopy, genes and chromosomes are analyzed for arrangement and organization - Chrm number and structure  - Maps genes and study chromosome structure and abnormalities in chrm number and organization - Karyotypes: standardized arrangements of chromosomes for diagnosing or ruling out genetic disorders - Each chrm is paired and arranged by size and shape - Molecular genetics: biochemical aspect - Recombinant DNA technology produces millions of clones of genes for study - Helps understand how genes are organized and function molecularly - Utilized in gene therapy: transfers human genes as treatment for genetic disorders - Ex: GMOS - Rec. DNA used in Human Genome Project to sequence the human genome: the complete set of genetic information an individual carries creating the new field of genomics – aka all 46 DNA molecules of 24 distinct types; the entire set of DNA instructions, as a whole - Genomics study the origin, function, and evolution of genes and their interactions - Population genetics: how much variation exists in a population and what alters the frequency of genes - The forces that change the frequency of genes in a population over many generations and its influence on evolution - Forces: migration, population size, and natural selection to change variation - Helps to understand the evolutionary history of our species and the migration patterns that distributed humans - Helped to develop: DNA fingerprinting and DNA identification used in paternity testing and forensics. Basic vs applied research - Basic research: figure out how something works or why it works the way it does - Goal is knowledge  - Result: generate new ideas and more basic research - Example: in genetics→ learn about genes, how they work, and why they do not function properly - Applied research: to solve a problem or create a service or product - Goal: develop something or solve something - Example in genetics→ transmission genetics, biotech products (GMOs), new tests, make vaccines - Labs are working to move results of genetic research from the lab to clinical practice : translational medicine Impact of genetics on social policy and law - Eugenics: the attempt to improve the human species by selective breeding - Galton proposed that selection should be used to improve the human species - Rational was flawed bc he believed traits are inherited without environmental influence - Hereditarianism: all human traits (phenotypes) are handed down without environmental influence - Intellectual, economic, and social level of humankind could be improved by selective breeding through applying the principle of natural selection - Desirable traits should be encouraged to have families - Undesirable traits should be discouraged from reproducing - US - Laws restricted reproductive rights and required certain (genetic disorders and those convicted of certain crimes) individuals to be sterilized - Immigration laws after WWI restricted entry of populations deemed genetically inferior (Immigration Restriction Act of 1924) - Law changed in 1965 - EXAMPLE: Carrie Buck and 60K others in the US were sterilized for “appearing” genetically, intellectually, or morally “inferior” - Being “feebleminded and promiscuous” were genetic traits - Sterilization happened until 1979 in some states - Nazi Germany - Laws justifying genoside of individuals believed to ve genetically inferior were modeled on the sterilization laws and eugenics movement in the US - Eugenics movement was used as justification for the eradication of entire ethnic groups like the Jews The Impact of Genomics - Genes associated with 100s of genetic diseases have been cloned (recombant DNA technology) and are used to devolop genetic tests and therapies - EX: HGP - Single Nucleotide polymorphism : single nucleotide differences between and among individuals in a population/species - The simplest type of variation - The effects of SNPs on complex traits and disorders are being studied using genome wide association studies (GWASs) - Haplotype: a set of SNPs located close together on a single chromosome or chromosome region - Show differences of individuals at the molecular level - GWASs: analysis of genetic variation across an entire genome searching for associations between variations in DNA sequence and genome region encoding a specific phenotype (cancers, alzheimers, mental illness) - Genome screening using DNA microarrays/chips are used to assess genetic risk in families by screening the entire genome - The microarrays carry DNA from the entire human genome to determine genetic diseases or risk - Stem cells - In the embryo stem cells divide to form 200 different cell types that become part of tissues and organs - Regenerative medicine: ability to isolate stem cells from embryos and to produce stem cells from somatic cells (diploid, body cells) in the lab (aka induced pluripotent stem cells) to treat disorders - GMOs - More than 85% of corn and 95% of soybean are GMOs - More than 80% of processes foods in grocery stores are from transgenic plants