_________________________________Biosocial Criminology: Genetic Origins of Behavior : Pages 50-70 Molecular Genetics Epigenetics video will be on test (Look it up!)Needed to identify the genes that are tied to the development of antisocial phenotypes BG (behavioral genetics) illustrated 3 main points about phenotypes:- Heritability: Most (if not all) phenotypes have strong genetic component- shared environment has little influence- non-shared environmental influential But, which genetic components are influential for certain phenotypes?What specific genes are responsible for the possession and/or expression if certain phenotypes? BG research designs are unable to provide informationRequires different research design: molecular geneticsIntroduction to Genetics Deoxyribonucleic acid (DNA) is a chemical code found in the nucleus of all cells expect red blood cells and contains the genetic blueprint that allows humans and all other living organisms to live. - influences observable human characteristics (hair and eye color) and non- physical (personality, disorders, disease) Parent to offspring and DNA is distinct from everyone else’s (MZ twins have same DNA) - partially responsible for creating person to person differences in every human phenotype, including antisocial phenotypes Chemical code that allows us to form, develop, and function/ liveStored in the nucleus of every cell except red blood cellsInformation encoded into DNA partially determines every observable and unobservable characteristics People vary (are different) because their DNA variesEvery person has their own unique sequence of DNA- exceptions: Monozygotic twinsEach person’s arrangement of genes is referred to as genotype- A genotype is a phenotype, but there is a variance due to things like dominant and recessive genes Genetic factors: Each fiber is referred to as PolynucleotideTwo fibers twisted around each other to form a double helix - nucleotides referred to as bases- A Adenine *can only bond with T- T Thymine *can only bond with A- G Guanine *can only bond with C- C Cytosine *can only bond with G** will not be tested on name, just letters and corresponding The ordering of base pairs is important.- you will get very different results in terms of phenotypes if pairs vary in ordering Very small divergences can alter drastically what we are studyingDifferences in genotype can cause significant changes in phenotypesThese base pairs working in collaboration are called genes Configured on threadlike structures called chromosomesThe human body contains 23 pairs of chromosomes- one pair is inherited maternally- one pair is inherited paternallyEvery person has two copies of most genes- one from mom and one from dadChromosomes23rd pair is sex differentiated - XX: girl- XY : boyThe Y chromosome is responsible for our history of violence, jealousy, aggression, murder, etc.The two copies of each chromosome make up the entire geneEach copy is referred to as an allele- 2 alleles= 1 geneAllelesFor most genes, only one allele exists in the populationBut for a small fraction of genes, there are at least two alleles that are in existence known as polymorphisms What should researchers focus on?Genes that have functional differencesLess concerned with those produce similaritiesSimilar to the population heterogeneity perspectiveDifferent polymorphisms can affect the functioning of the human bodyMG analyzes which polymorphisms affect various phenotypes Three ways genes can affect phenotypes: 1. One gene, one disorder (OGOD)2. Polygenic effectsexample: 3 genes, 1 phenotype3. Pleiotropic effectexample: 1 genes, 3 phenotypeProteins are complex organic compounds that are essential to human life- provide shape to cells or functional properties such as aiding metabolism example: enzymes Amino acids (20 in total) are the building blocks of proteins and are coded for by sequences of 3 contiguous base pairs known as codons (CCA) Exons are part of a gene that code for protein production Introns are the parts of a gene that are non coding - Exons and introns are interspersed throughout the human genome Main function of genes is to code for the production of proteins- Genes do not directly manufacture proteins, they only contain the instructions needed for protein to be produced Central dogma of molecular biology (process by which genetic information is converted into proteins): 1. Transcription is the process where a gene duplicates itself onto a new molecule called ribonucleic acid (RNA) - RNA contains all the information needed to manufacture the amino acids that will result in the production of proteins- once is has been copied, RNA leaves the cell nucleus and enters the cytoplasm DNA differs from RNA in at least three ways: 1. Gene is duplicated, the introns are removed in a process called splicing 2. RNA is a single stranded, while DNA is double stranded 3. DNA and RNA use somewhat different genetic alphabets 2. During translation, mRNA meets up with and attaches itself to a ribosome, which are protein manufacturing machines found in the cytoplasm - Ribosome then reads the genetic information carried by mRNA and works in conjunction with another type of RNA to produce the appropriate amino acid - after the amino acid is produced it’s added to a growing protein chain, polypeptide chain, which includes other amino acids that have already been produced and linked together- once protein is formed, it migrates away from the ribosome and performs its specialized function for the cell - a gene is copied from DNA to RNA - RNA works in conjunction with ribosome’s to produce a protein (responsible for bringing about phenotypes) Human Genetic Variation Difference in DNA sequences can result in differences in phenotypes including antisocial phenotypes Genes are inherited on threadlike structures called chromosomes - There is only one copy of the gene and genes do not vary from person to personSex chromosomes- females: inherit two X chromosomes - males: inherit one X chromosome and one Y chromosome Remaining 22 pairs are called autosome and are referred to by a distinct number (#1-#22)- genes located on autosome are either inherited on the maternal chromosome and one on the corresponding paternal chromosome Location where a gene is found is a genetic locus Alternative copies of a gene are referred to as allelesGenes that consist of two or more alleles are called genetic polymorphisms - Genes that consist of two identical alleles are