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University Degree: Genetics
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During mitosis, or M phase, cell division occurs and segregates one set of diploid chromosomes to each daughter cell. The two gap phases (G1 and G2) serve as more than simple time delays to allow cell growth. They also provide time for the cell to monitor the internal and external environment to ensure that conditions are suitable and preparations are complete before the cell commits itself to the major upheavals of S phase and mitosis. If extracellular conditions are unfavourable, for example, cells delay their progress through G1 and may even enter a specialized resting state known as G0 in which they can remain before resuming proliferation.
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The activity of the Ntr regulon alters as a result of the nitrogen supply which is available to bacteria. The genes that are encoded by the Ntr regulon are affected by the supply of ammonia that the bacterial cell has. In this way, the activation of these genes within the Ntr regulon are regulated by the supply of ammonia (and therefore acts to sense these levels of ammonia). There are many different nitrogen sources, organic and inorganic, that can be taken up by bacteria, including nitrate, nitrogen gas or urea, but whatever the source, it will be converted to ammonia.
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IVF treatment however, can also require large numbers of human eggs, with as many as 10-15 being harvested at each attempt, given that it may take several procedures to result in a successful pregnancy1. Following on from that is the increased incidence of developmental abnormalities noted in cloned mammals, found in approximately one third of procedures. It has been found however that cloning rhesus monkeys produces no developmental or physiological abnormalities. Developmental abnormality however, occurs in 3% of natural pregnancies (and even more when maternal age is over 40 years).
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These are repeated sequences which are 9-24 base pairs in length. These highly polymorphic minisatellites share a common core sequence and appear near talomeres.(6) Microsatellites and Tetranucleotide / trinucleotide (STR's) repeats are other markers which can be used. The tandemly repeated consensus sequences are only two to five bases long. Compared to minisatellites, the shorter repeat lengths of STR markers make them more compatible with use of the Polymerase chain reaction (PCR). PCR is a way to amplify minute amounts of DNA. This advantage has made them popular and useful markers for recent genetic maps.(3), (2).
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that contains genes, which play an important role in the bacterium. This can often be a gene that encodes a protein, which makes the bacteria resistant to an antibiotic. Plasmids are present in multicopy within bacteria, and they are replicated independently from their own origin of replication. Plasmids probably came about as a result of bacteria evolving in close proximity to other heterotrophs. Bacteria often grow in the same environment as molds and fungi and compete with them for food (complex organic material). As a result, molds and fungi have evolved to make toxins that kill bacteria.
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e. Based on your conclusion of the gel, what is your conclusion about the DNA samples in the photograph? Do any of the samples seem to be from the same source? If so, which ones? Describe the evidence that supports your conclusion. Sample four, or suspect two, matches the DNA from the crime scene perfectly. This must mean that the DNA fragments came from the same source and were cut by restriction enzymes in the same place. 2. A restriction endonuclease "cuts" two DNA molecules at the same location. What can you assume is identical about the molecules at that location?
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Improper handling of evidence or failure to recognize forensic evidence undermines the value of DNA analysis. States and the federal government should make the analysis of DNA forensic evidence a priority and support the expansion of CODIS (Combined DNA Index System). DNA analysis becomes more valuable as the size of offender databases increases. As more offender DNA profiles are entered into state databases and CODIS, the probability of a match or "hit" increases exponentially. States and the federal government should provide the resources necessary to enter the DNA of all offenders covered by law into DNA databases as quickly as possible. Criminal justice professionals need to be educated about the value and limitations of DNA analysis.
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Now, the scientists are hoping they can genetically engineer these pesky insects so that even if they acquired parasites or viruses, they are unable to pass them on. The parasites of malaria and other diseases enter the body of the mosquito, live safely and multiply, and eventually transfer over to the salivary glands of the mosquito. There it waits to be delivered to the next victim when the insect feeds again. The idea is to interrupt the relationship between the insect and its pathogens that use it for transport.
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I will illustrate the problems that have surfaced and discuss some measures that may help solve them. Up until now, police have used methods of blood and protein typing, footprints, drug and firearm matching and eyewitness identification to place a suspect at the scene of a crime. Genetic fingerprinting technology has been applied to evidence from many crime scenes and the results have often shown previous technology to be frighteningly unreliable. In a study of 28 cases commissioned by the National Institute of Justice (Conners, Lundregan, Miller, McEwan, 1996)
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The process has allowed researchers to create thousands of plants inexpensively ("Cloning" 1). Despite all the knowledge of cloning, the first animal clones were formed only one hundred years ago. During the late 1800s, Hans Dreisch created the first cloned animals. His experiment involved the use of sea urchins, which have large embryos. Dreisch took the two-celled embryo of an urchin and vigorously shook the embryo in a beaker full of sea water. The embryo eventually split and each cell became a separate sea urchin.
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and the clamp loader complex (the delta, the delta prime, the gamma, the chi and the psi subunit.) In addition, the tau subunit serves as a scaffold to help in the dimerizaton of the core complex through the two ? chains of the separate core enzymes by sequence homology with the gamma subunit. The core enzyme has very low processivity - only 10-15 residues. Thus, it is only able to 'fill-in' short regions of single stranded DNA. The holoenzyme is created from seven other subunits (�, delta, delta prime, chi, gamma, psi, and tau) that bind to the core.
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These are much stronger than the wire type needle and are used much more in industry. Another type of needle is known as the compound needle. This consists of two parts, the needle part, which is the stem and the hook of the needle, and also a tongue part, which is the hook-closing element. This is the most expensive type of knitting needle and costs around �3.
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This now provides a very powerful tool for forensic crime scene investigators. 2. Types of Cases: To answer the question of what types of cases DNA profiling is used in we looked to an Internet source, which provided us a table of case percentages. Type of Case Percentage of Cases Homicide 20 Sexual Offenses 60 Assaults 7 Burglary/Robbery 7 Criminal Damage 1 Other 5 1 DNA profiling is usually carried out when human biological tissue or fluid is found at a crime scene, and can be used to link a possible suspect to a case.
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Humans have 23 pairs of chromosomes containing the DNA blueprint that encodes all the materials needed to make up your body as well as the instructions on how to run it. One member of each chromosomal pair from your mother and the other from your father. Every cell in your body contains a copy of this DNA; most of it does not differ from human to human. However, some 3 million base pairs of DNA (about 10% of your entire genome)
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They are extremely complex macromolecules, and each type of protein has its own individual three dimensional shape, but are all made up of the same 20 amino acids in different arrangements. Amino acids are linked together in an unbranched chain by peptide bonds to form polypeptides. This bond is formed when the amino group of one amino acid is next to the carboxyl group of another and an enzyme is introduced to cause a condensation, or dehydration, reaction, where a molecule of water is lost between the two molecules.
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The first method of purification that I shall describe is also one of the simplest. It relies on the physical properties of the protein itself by making the desired protein precipitate out whilst keeping other proteins and 'background' matter in solution. Protein solubility can change as ionic strength of the solution changes and generally they have different solubility curves, but a general trend is that protein solubility decreases as ionic strength of the solution increases. So if you have a mixture of proteins then carefully increasing the salt content can precipitate out some proteins but not others if they react in different ways to the change in salt content.
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The joining up of one nucleotide to another, between the sugar and phosphate groups forms a polynucleotide chain. In DNA molecules, the nucleotides contain one of the four bases - adenine, guanine, cytosine or thymine. In RNA molecules, the nucleotide contain one of the bases - adenine, guanine cytosine or uracil, which shows that RNA replaces thymine with uracil and is single stranded unlike the double stranded DNA. In 1951, American chemist Erwin Chargaff analysed DNA by using chromotography to separate the four bases in DNA. The amounts of each base were measured quantitatively and the results showed that adenine and thymine were similar and the amounts of cytosine and guanine were similar.
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Perhaps the most famous part of the Sistine Chapel ceiling is called "The Creation of Man," where God and Adam sail through the clouds with arms outstretched, the tips of their index fingers just barely touching.
The National Bioethics Advisory Commission is a 15-member advisory panel of legal and medical academics established to counsel the President on biogenetic research, animal husbandry, and biotechnology in general. Following the announcement about the cloning of Dolly the Sheep, the President directed the panel to review the implications of cloning for humans and report to him within 90 days. Shapiro released a written statement to the press after White House spokesman Michael McCurry announced the directive: "It is very important for us to think extremely carefully about what ethical considerations arise when we even consider the idea of cloning human beings," Shapiro need look no further than his own faculty for help.
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or the negative electrode (cathode.) The direction in which they move depends upon the proteins net charge. If the protein molecule has a positive charge (cations), it will move towards the negative electrode (cathode), if however the protein molecule is negatively charged (anion) it will migrate towards the positive electrode (anode.) Each amino acid has an isoelectric point (pI) this is the point at which the molecule has an average net charge of zero, this is the pH level at which there is no migration in an electric field.
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breaks up the two and three dimensional structure of the protein by adding a negative charge to all the amino acids straightened out. In denaturing, (SDS PAGE) separations, migration is determined not by intrinsic electrical charge of the polypeptide but by molecular weight between log molecular weight and (RF) distance migrated by the protein/ distance migrated by the dye front. It is usually necessary to reduce disulphide bonds in proteins before they adopt the random coil configuration necessary for separation by size; this is achieved with the addition of 2-mercaptoethanol or dithiothreitol which was carried out in this investigation.
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Several years later, another sexual assault was committed. A Sexual Assault Nurse Examiner worked with the victim and was able to obtain biological evidence from the rape. This evidence was analysed, the resulting profile was run against a DNA database, and a match was made to the man's DNA profile. He was apprehended, tried, and sentenced for his second crime. In this hypothetical case, he was also prevented from committing other crimes during the period of his incarceration. DNA evidence is generally linked to DNA offender profiles through DNA databases.
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DNA Fingerprinting: A review of the criticisms of DNA evidence. Is it really the absolute identification evidence?
Furthermore, the sample cannot produce an accurate profile if it has been subject to degradation. The significance of a match after the profiling process is also an area where lawyers have challenged DNA evidence. There may be unexplained discrepancies between two profiles, or inaccurate databases chosen. The presentation of DNA evidence in the courtroom has been a difficult task, both for the prosecution and the judge to present and for the Jury to understand. It has been argued that the most contentious debate in forensic science involves the use of statistics to estimate the rarity of a given DNA profile4.
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DNA analysis has become an effective procedure in forensic genetics. Prior to 1985, the methods of analyzing biological samples were limited to only conventional blood group and enzyme analysis in criminal cases (Capelli et al, 2003). These methods were informing but nevertheless only gave surface analysis. The advent of the polymerase chain reaction (PCR) changed this phenomena and made DNA analysis an endless scope applicability. Capelli et al states that it allowed forensic experts to address the most inaccessible sources of DNA evidences (such as cigarette butts, fingerprints etc. which are predominant in criminal cases)
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o Rickettsia prowazekii (epidemic typhus) o Mycobacterium tuberculosis (tuberculosis) * Nematode C. elegans ( ~ 4 x 108) - December 1998 * Drosophila (fruit fly) (2000) * Human genome (rough draft completed 5/00) - 3 x 109 base Bioinformatics is basically recording, annotation, storage, analysis, and searching/retrieval of nucleic acid sequence (genes and RNAs), protein sequence and structural information. The various data bases used to analyse this information woud be explained further. There are different ways to analyse and interpret information.  * To determine the genes in the DNA sequences of various organisms present in the Genbank.
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The blood-group typing was implemented in crime labs and has remained useful in many crime solving techniques today. Advances in blood typing have concentrated on the different enzymes and proteins associated with the major blood groups because they have the characteristic of being polymorphisms, which means they exist in several forms and variants, so each one of them have subtypes. The early work on blood proteins was performed on enzymes such as Phosphoglucomutase (PGM), Haptoglobin (Hp) and Adenylate Kinase (AK).
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