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 information Requires different research design molecular genetics Introduction 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 live Stored in the nucleus of every cell except red blood cells Information encoded into DNA partially determines every observable and unobservable characteristics People vary are different because their DNA varies Every person has their own unique sequence of DNA exceptions Monozygotic twins Each 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 Polynucleotide Two 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 studying Differences in genotype can cause significant changes in phenotypes These base pairs working in collaboration are called genes Configured on threadlike structures called chromosomes The human body contains 23 pairs of chromosomes one pair is inherited maternally one pair is inherited paternally Every person has two copies of most genes one from mom and one from dad Chromosomes 23rd pair is sex differentiated XX girl XY boy The Y chromosome is responsible for our history of violence jealousy aggression murder etc The two copies of each chromosome make up the entire gene Each copy is referred to as an allele 2 alleles 1 gene Alleles For most genes only one allele exists in the population But 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 differences Less concerned with those produce similarities Similar to the population heterogeneity perspective Different polymorphisms can affect the functioning of the human body MG analyzes which polymorphisms affect various phenotypes Three ways genes can affect phenotypes 1 One gene one disorder OGOD 2 Polygenic effects example 3 genes 1 phenotype 3 Pleiotropic effect example 1 genes 3 phenotype Proteins 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 a gene is copied from DNA to RNA RNA works in conjunction with ribosome s to produce a protein responsible for bringing function for the cell 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 person Sex 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 alleles Genes that consist of two or more alleles are called genetic polymorphisms Genes that consist of two identical alleles are homozygous example AA genotype example aA genotype Genes that consist of two different alleles are heterozygous Three different types of genetic polymorphisms 1