Forensic Genetics
FZ3011 Forensic Genetics SECTION A Short Tandem Repeat Polymorphisms Structure STRs, also known as microsatellites or simple sequence repeats (SSR), are 2-6bp DNA sequences tandemly repeated units flanked by unique sequence. They are usually between 100-300 bp long. They are classified based on the structure of the number of core repeats (base pairs): * Dinucleotide - 2 * Trinucleotide - 3 * Tetranucleotide - 4 * Pentanucleotide - 5 (Russell, 2006). They are also divided into categories depending on the type of repeats: * Simple - contain the exact same sequence and length with non-consensus alleles. * Compound - contain repeats of two or more adjacent simple repeats (non-consensus). * Complex - can be of several repeat blocks, varying sequences or intervening sequences. * Hypervariable - complex repeats with numerous non-consensus alleles, e.g. STR loci SE33 or ACTBP2. * Microvariants - contain alleles with incomplete repeat units, e.g. allele 9.3 at TH01 locus (Butler, 2005). Occurrence They are scattered throughout the genome and occur approx. every 10,000 nucleotides (Butler, 2005). Methods of Detection * Fluorescently labelled primers in PCR products are passed through Capillary Electrophoresis. As labelled PCR products migrate through the gel towards the anode on the laser they separate based on their size. Fluorescence is measured from exciting a
Cloning argument
Cloning Cloning has long been a controversial topic for mankind. When scientist cloned its first sheep, many people were in disbelief. Some people see this as advancement in science, and it definitely is, but is it advancement in the right direction? I believe it is not. Cloning research employing human cells is ethically wrong and should be strictly prohibited. Consider this: "...a fertilized egg is a person, entitled to full human rights. Taking stem cells out of a blastocyst is no different from cutting the heart out of a baby (Postrel p.322)." It is ethically and morally wrong to clone a human being which will eventually be killed anyway just to prolong the life of someone else. This allows us play God and it should not be like this. Death is inevitable for a human being, and as a human being we should know and accept this. Not only should stem cell research be prohibited, but so should the research of trying to clone a human being to live as long as non-cloned human. In an article written by Michael A. Goldman, he states that human cloning is "unnecessary and probably impossible anyway (p.329)." With this in mind ask yourself that same question: "Is human cloning necessary?" Because I believe it is not. But the public may say it would be a great thing for people who cannot reproduce. There are alternatives for this, adoption, and in vitro fertilization. The
Discuss the role of genetics in modern civilisation.
J. Read BIO 005 Dr. A. Jha Discuss the role of genetics in modern civilisation In April 1953 James Watson and Francis Crick published a paper in "Nature" describing their discovery of the double helix structure of DNA. In 2003 we are beginning to see the huge impact that the discovery has had on all our lives, in agriculture, medicine and the environment. Genetics is the scientific study of heredity and hereditary variation, the similarities passed from one generation to the next and the differences each offspring possess. Today genetics is at the centre of many of societies most crucial debates, from the safety of genetically modified foods to the ethics of designer babies. It has solved crimes due to the unique fingerprint DNA provides, brought cloning from the realm of science fiction with "Dolly the Sheep", and will provide cures for genetic-related diseases. Age-old questions about life are being answered and many aspects of how we understand the world around us are being transformed. Genetics and DNA scientific study is catalysing progress in every other biological field, physiology, evolutionary biology, ecology and behaviour. The impact of genetics research and development has been massive and therefore major ethical issues come with it. We can create new organisms and understand the patterns of diseases but with that power comes responsibility and risk.
Imagine that you are a behaviour geneticist interested in the heritability of personality attributes. Describe how you would go about studying the genetic basis of personality
A critical look at studying the genetic basis of personality Name: Arpun Kaur Bajwa Student #: 20096989 Course #: Psych 356, Personality Theory Assignment #1 Question #5 - Imagine that you are a behaviour geneticist interested in the heritability of personality attributes. Describe how you would go about studying the genetic basis of personality. What would your basic procedure be? What measurement issues would you face? How much would you draw on psychological theories of personality? Which theories? Date: January 25, 2006 Personality Theory - 1st Assignment - Question #5 Behavior geneticists assess the question of inheriting personality. Are our genes responsible for our creativity, aggressiveness or confidence? Examining personality traits through a genetic focus is an obscure task. Methods employed by behavior geneticists involve epidemiological studies, such as screening family pedigrees, conducting twin heritability studies, and adoption studies. In this essay, I will discuss the methodology behind twin studies as well as many issues that behavior geneticists face. I will also present information regarding other personality theories and their relationship to behavior genetics. I believe that behavior genetics plays a very important role in understanding personality traits and should be kept in the forefront of psychology as a prominent research theory.
Nucleic acid, DNA replication and Protein Synthesis
Bina NUCLEIC ACUD, DNA REPLICATION AND PROTEIN SYNTHESIS Mohammed Majeed Mohammed Majeed Bina Biology key skills Poodles make more poodles. Sheep make more sheep. Replication is a basic fact of life. All living things make other living things that are to one degree or another duplicates of themselves. What is the mechanism behind all this? The answer lies in a molecule called DNA. In 1869, Friedrich Miescher extracted a substance, which he called nuclein from the nuclei of white blood cells. Nuclein later became known as nucleic acid. Living cells contain two kinds of nucleic acids-ribonucleic acid (RNA) which contains the sugar, ribose and deoxyribonucleic (DNA) which contains the sugar, deoxyribose. Nucleic acids are found in all living things, from the simplest protozoan to the most complex forms of animal and plant life . Two young scientists-James Watson and Francis Crick-finally pieced together the precise structure of DNA. The model proposed by Watson and Crick for the structure of DNA is shaped like a twisted ladder. This type of figure is known as a double helix. The sides of the twisted ladder are made up of alternating units of deoxyribose and phosphate. The rungs of the ladder are composed of paired nitrogen bases. Adenine always pairs with thymine, and guanine always pairs cytosine. The bases are held together by hydrogen bonds. Watson and Crick's
Transcription in eukaryotes and prokaryotes.
Transcription in eukaryotes and prokaryotes 25 March 2003 General introduction to transcription Both eukaryotes and prokaryotes use various forms of the enzyme RNA polymerase to catalyse the process of transcription. The unwinding of the DNA helix in order to synthesise RNA occurs as part of the function of prokaryotic RNA polymerase, whereas eukaryotes use additional proteins to perform this function within the nucleus, after which the RNA migrates through pores in the nuclear envelope to the cytoplasm where protein synthesis occurs in association with ribosomes. Each triplet codon in the mRNA is formed into amino acids and correctly inserted into a polypeptide chain. RNA is synthesised in the 5' -to- 3' direction from the template DNA strand, read in the opposing 3' -to- 5' direction. Maturation of RNA from the primary transcript involves complex stages known as processing, involving modifications of pre-mRNA such as the addition of a 5' cap and a 3' tail, this type of heterogeneous nuclear RNA, denoted hnRNA, is located only in the nucleus. These molecules can be very large in size up to 107 daltons and often is complexed with proteins forming heterogeneous nuclear ribonucleoproteins (hnRNPs). Only about a quarter of these are converted into mature RNA, large segments are excised and the remaining segments are spliced together prior to
Compare and contrast the different techniques used in separating biomolecules.
Compare and contrast the different techniques used in separating biomolecules Aim The aim of protein purification is to remove or isolate one particular protein from a solution containing a mixture of other molecules In this assignment, I will assess the effectiveness of different techniques used to separate bio molecules (proteins and lipids) by comparing these techniques and exploring the best technique for separating proteins products. I will also discuss the application of biomolecule separation techniques in medicine, industry and for economical reasons. Introduction Protein bioseparation refers to the recovery and purification of protein products from various biological materials and is important in food, pharmaceutical, and biotechnological industry. Protein based products need to be purified before they can be used. Bio molecules produced in cell culture (whether in bacteria, yeast, or other cells need to be separated from potentially toxic components of culture. Column Chromatography and electrophoresis are some of the most used techniques for separating and purifying these substances. Protein based products include . food and nutritional products 2. pharmaceutical products 3. industrial catalysts 4. diaganostic products biomolecular separation is based on properties such as size charge and function. An ideal protein bioseparation process must combine
Protein Synthesis
Protein Synthesis Proteins make up over half of the dry mass of a cell. Protein synthesis is therefore central to the maintenance, growth and development of the cell. In preparation for protein synthesis, a specific transfer RNA molecule must be attached to each of the 20 common amino acid and the ribosomal subunits must be preloaded with supplementary molecules. During protein synthesis, these components are brought together in the cell cytoplasm in a ribosome complex. At this point a single mRNA molecule is transported step by step into a ribosome. In doing so, its sequence of nucleotides can be translated into its subsequent amino acid sequence to make a unique protein chain. Using the Central Dogma of Biology: DNA transcription RNA translation Protein protein synthesis can be broken down into two major processes: transcription and translation. Transcription In transcription the genetic material of an organism (the DNA) acts as a template on which an mRNA polynucleotides chain is formed. The reaction is necessary for the transfer of information from DNA to protein. It is catalysed by the enzyme RNA polymerase. RNA polymerase binds to the promoter, a specific DNA sequence that indicates when RNA synthesis should begin. After binding to the promoter, the RNA polymerase unwinds one coil of the DNA helix. This exposes a short section of single-stranded DNA
Structure of DNA
The Structure of DNA (The Double Helix) DNA is made up of six smaller molecules -- a five carbon sugar called deoxyribose, a phosphate molecule and four different nitrogenous bases (adenine, thymine, cytosine and guanine). Using research from many sources, including chemically accurate models, Watson and Crick discovered how these six subunits were arranged to make the the structure of DNA. The model is called a double helix because two long strands twist around each other like a twisted ladder. The rails of the ladder are made of alternating sugar and phosphate molecules. The steps of the ladder are made of two bases joined together with either two or three weak hydrogen bonds. Nucleotides The basic building block of DNA is called a NUCLEOTIDE. A nucleotide is made up of one sugar molecule, one phosphate molecule and one of the four bases. Here is the structural formula for the four nucleotides of DNA. Note that the purine bases (adenine and guanine) have a double ring structure while the pyrimidine bases (thymine and cytosine) have only a single ring. This was important to Watson and Crick because it helped them figure out how the double helix was formed. These pictures show a ball and stick model of two DNA nucleotides. Gray balls are carbon atoms, blue balls are nitrogen, red balls are oxygen and the pink ball is phosphorous. The hydrogen atoms are not shown.
IRES (Internal Ribosomal Entry Site) Identification in Regulation and Gene Expression.
TITLE: Title: IRES (Internal Ribosomal Entry Site) Identification in Regulation and Gene Expression. 2 CONTENT: 2.1 Introduction Molecular biology and the equipment available for research have rapidly increased the sequencing of large portions of the genomes of different species. Currently several bacterial genomes, as well as those of some simple eukaryotes (e.g., Saccharomyces cerevisiae, or baker's yeast) and more complex eukaryotes (C. elegans and Drosophila) have been sequenced in full. Various online sites and databases have aided bioinformaticians to do this [1]. The speed in which the Human Genome Project was carried out is truly amazing and can only depict on what is yet to come Various famous sequence databases, such as GenBank and EMBL, NCBI have been growing at exponential rates. The information present is these data base is enormous. This deluge of information has necessitated the careful storage, organization and indexing of sequence information. Information science has been applied to biology to produce the field called bioinformatics. 2.2 LANDMARK SEQUENCES COMPLETED [2] * First complete DNA genome: X174 DNA (1977) - 5386 bases * human mitochondrial DNA (1981) - 16,569 bases * tobacco chloroplast DNA (1986) - 155,844 bases * First complete bacterial genome (H. Influenzae)(1995) - 1.9 x 106 bases * Yeast genome (eukaryote at ~ 1.5 x 107)
