1. Tay-Sachs disease is a rare genetic disorder that destroys nerve cells in the brain and spinal
cord. There is currently no cure for the disease. Answer the following questions in relation to the
a) What are lysosomes? (2 marks)
b) Tay-Sachs disease results from mutations in the HEXA gene. What are the effects of the
gene mutation in the cell? (2 marks)
c) What are gangliosides, where in the body are they most abundant and what happens when
their cellular concentration increases? (2 marks)
d) Symptoms usually begin in children before six months of age. What are the clinical
ramifications of the disease? Mention at least two for full marks. (2 marks)
After visiting a country picnic, where Jack had eaten a slice of watermelon from a local
producer, he fell ill and was taken to the local clinic. According to the clinical signs, of which
there were many, he was diagnosed with organophosphate poisoning. It turns out that the
watermelon had been sprayed with an insecticide containing the chemical organophosphate.
a) Using a labelled diagram, outline the sequence of events that occurs at the neuromuscular
junction after an action potential is propagated to the axon terminal of a neuron. Use
Acetylcholine as the example and include a description of each step up to
neurotransmitter binding. (3 marks)
b) Provide a general description of each of the mechanisms for neurotransmitter removal
after it is used. (1.5 marks)
Specifically, how is Acetylcholine removed? (0.5 mark)
c) Explain what organophosphates are and how they interfere with neurotransmission.
d) Name at least two of the clinical signs manifested by organophosphate poisoning in the
autonomic nervous system. Include the receptor type for full marks. (2 marks)
(Voula Gaganis) (8 marks total)
4. Following an illness due to campylobacter infection, a young University student presents to his
GP with weakness in his limbs and absent reflexes including the knee-jerk reflex. Sensory
testing in his feet to light touch, pressure, vibration, and temperature were conducted. In
addition, a sample of cerebrospinal fluid was taken. The patient was provisionally diagnosed
with a disease of the peripheral nervous system affecting production of myelin.
a) What is myelin? Provide a brief description of its composition and function. How is myelin
produced in the central and peripheral nervous systems? Include the specific cells
responsible. (2 marks)
b) Provide the rationale for the sensory testing. What would you expect the findings to be?
c) Using a diagram, provide a detailed description of how the knee-jerk reflex works. Why
was the knee-jerk reflex absent in the patient? (3 marks)
d) What is cerebrospinal fluid (CSF)? Where is CSF usually sampled from and why? How
does CSF sampling help support the diagnosis of a demyelinating disease?
Presentation The Food and Agriculture Organization nearly 20 years prior discharged a paper expressing that the measure of sustenance delivered worldwide won’t have the capacity to give the consistent wholesome needs to the total populace by this year (2010) as an amazing 25% expansion in total populace was anticipated, however this estimation has not appeared, it has created a great deal of worries as there has been a 4-overlay populace increment in the most recent century (1918 – 2009) which has prompted the uses of biotechnology to farming or at the end of the day the “Agrobiotechnology” to improve most extreme nourishment generation in a financial way. The requirement for the utilization of biotechnology to crops was additionally required because of the enormous harvest misfortune because of creepy crawly bothers as around then was treated with pesticides which are costly and accordingly there was a need to maintain the efficiency yields of products which was not given a lot of a shot as total populace was on the ascent. Biotechnology could give prospects of creating novel, created, more secure and reasonable yields in agrarian practices. (Darker, 1992) Farming is characterized basically as the exercises associated with the creation of nourishment yields and raising of domesticated animals creatures, while biotechnology was characterized together by FAO and WHO (1996) as “the joining of regular sciences and building sciences so as to accomplish the use of living beings, cells, parts thereof and sub-atomic analogs for items and administrations”. Consequently Agrobiotechnology systems as indicated by Huttner et al, (1995) are actualized to decrease cost of creation of harvests and expanding sustenance efficiency by; expanding nourishment quality and sustenance handling characteristics, satisfactory sickness or vermin protection, enhancing natural pressure resilience, and the control of weeds which has prompted the improvement of (hereditarily adjusted) GM trims in a few sections of the world. Plant reproducing strategies with the utilization of atomic markers, for example, RFLP, RAPD, AFLP, SSRP, CAPS and SSCP were enhanced for plant’s genome mapping and additionally to decide plant’s phenotypes and select attractive qualities for the best possible alteration of products relying upon the quality of intrigue that will be fused into a few populaces of plants or yields created by crosses. (Mohan et al, 1996) A few biotechnology approaches have likewise been connected in domesticated animals cultivating essentially in light of the fact that there is a general conviction that the biotechnological ventures to people are only one stage in front of those connected to creatures which includes the adjustment of creatures to watch attractive qualities. (Becker and Cowan, 2009) As indicated by Fernandez-Cornejo (2008), the crucial commitments of the use of biotechnology to farming relies upon the affirmation of its imminent conceivable advantages and dangers, notwithstanding, this article will center around the potential commitments of biotechnology to agribusiness (plants and creatures) considering the preferences and in addition the weaknesses of the innovation Plant (Crop) Biotechnology Plant biotechnology advancements depended on the cell hypothesis as portrayed by Vasil (2007) and has seen wonderful development over the most recent 10 years which has concentrated significantly on making crop generation effective and creating crops with wanted attributes. Plants and harvests need to defeat some Biotic and Abiotic worries to expand their efficiency which prompted the presentation of hereditarily adjusted (GM) edits around 20 years prior which have been marketed in the course of recent years either with single deceiver different qualities GM trims as the name suggests that qualities of a product are taken and exchanged to another yield or officially give qualities are controlled the primary motivation behind changing the highlights of the product being referred to which might be either the way the harvest creates or develops. Tended to in the following passage are characteristics that have been exchanged to biotechnology or GM harvests to expand their yield. Creepy crawly/bug protection – Ferry et al (2005) evaluated that 10 – 20% of significant products are lost to bugs or irritations and harvests are hereditarily altered to be noxious and destructive to bugs that assault the yields, an illustration is the utilization of Bt (Bacillus thuringiensis) qualities to develop cotton (in China and South Africa) and corn in this manner decreasing pesticide utilize, expanding benefits, yields and medical advantages to agriculturists who apply pesticides without defensive garments. (Nuffield Council on Bioethics, 2004) Ailment protection – Described in subtle elements by Raybould and Gray (1993), contagious, bacterial and viral pervasions to harvests and plants have been smothered by hereditarily altering plants to be ailment safe for instance the continuous research to decrease the viral and parasitic diseases to sweet potatoes and bananas individually. Abiotic push protection – Motavalli et al (2004) talked about the progressing broad research to adjust harvests to have the capacity to make due in troublesome natural conditions, for example, dry season, warm, chilly, ice, extraordinary soil conditions and altogether increment nourishment security for instance the utilization of trehalose qualities to develop rice in India to shield it from drying out. Herbicide resilience – This characteristic empowers an extensive variety of weeds to be controlled by adjusting yields to be impervious to the impacts of weed subsequently bringing down expenses of herbicides, diminishing culturing and powerful weed control measures as examined in Sharma et al (2002) in the development of soybeans in Argentina. Enhanced nutritious esteem – Plant biotechnologies has empowered yields to be altered to contain supplemental supplements insufficient in diets for instance the upgrade of β- carotene in rice to expand vitamin A to anticipate visual impairment which is because of vitamin A lack. Biopharmaceuticals – Biotechnology applications in plants has been utilized to deliver antibodies and prescriptions as indicated by Sharma et al (2002) which has empowered generation and simple appropriation of shoddy immunizations as in the alteration of potatoes to create bacterial antibodies for E.coli. GM crops have been generally acknowledged around the world (25 nations presently) both in modern and creating nations as appeared in figure 1 fundamentally on account of their points of interest which are either temperate or natural. Aside from the way that plant or harvest biotechnology has enhanced the profitability and yield of products, other monetary advantages in connection to the highlights of GM crops are additionally talked about; As depicted by Nuffield Council on Bioethics (2004), the development of a huge assortment of yields by ranchers have been upgraded as there a decent protection from biotic (creepy crawlies, bugs or ailments) and abiotic (dry spell, ice, warm) conditions. With the protection of GM yields to bugs and vermin, the utilization of pesticides is extraordinarily diminished which thusly lessens the expenses of developing these products. Ranchers can produce more pay attributable to the diminishment of the cost of cultivating and age of higher yields which therefore decrease the costs of harvests accordingly lightening destitution and starvation levels in the economy. GM crops have an enhanced sustenance levels therefore ailments and sicknesses are thusly deflected with a superior eating regimen even in immature nations. Since GM yields can stay fresher over a drawn out stretch of time for instance in tomatoes, the time span of usability can be expanded in the market. The capacity of GMO harvests to withstand abiotic conditions, for example, dry season has expanded nourishment security while the less expensive generation of biopharmaceuticals, for example, antibodies and different pharmaceuticals in GM plants has prompted an extraordinary simplicity of dissemination and produce of immunizations subsequently enhancing medicinal services frameworks. Ecological advantages of GM trims as examined by Gatehouse et al (1992); Wieczorek (2003) and Gatehouse (2005), incorporates the less utilize or no utilization of pesticides and bug sprays which might be contaminants in the earth (land or water) and could amass as deposits on nourishments along these lines more natural cordial pesticides can be utilized while as a rule there is no compelling reason to utilize pesticides. Normal assets maintainability is additionally enhanced as there is less utilization of vitality or chemicals (pesticides) while regular living spaces are moderated for more effective applications. GM crops have diminished the weight on vegetation and biodiversity is kept up while there is a less danger of desertification and soil disintegration since GM products can be become anyplace independent of abiotic conditions. As per the upsides of biotechnology depicted in figure 2 over, these advantages must be accomplished if the dangers and concerns which constitute the hindrances are researched, acknowledged and deflected. (Mannion, 1995). The potential dangers of biotechnology applications to harvests and plants can either be wellbeing related, natural or social as further examined. Wieczorek, (2003) examines the potential danger of bringing poisons and allergens into GM crops while hereditary change innovation is in progress is of extraordinary worry as there is a potential danger of allergens and poisons being moved into enhanced products while additionally underscoring the worries raised about the utilization of sub-atomic markers amid quality exchange as there is a potential danger of sicknesses being impervious to clinical anti-microbial medications because of exchange of protection encoding qualities which may contain novel bacterial strains. Of extraordinary worry as talked about by Hobbs and Plunkett, 1999 is the way that the long haul wellbeing impacts of the utilization of GM edits over quite a while is obscure. Of natural concerns is the potential danger of GM crops hybridizing with related weeds which may bring about superweeds that are more convoluted to oversee while hereditary change of plants could represent a danger of accidental quality exchange to non GM crops from GM trims subsequently the previous turn out to be wild plants making biological hazards as talked about by Soregaroli and Wesseler, (2003). Wieczorek, (2003) proposes that the arrival of GM crops>