...Main features of Plant Viruses and the diseases they cause Essay Viruses are small infectious pathogens, which are too small to be seen under a light microscope. However, despite their size they can cause both mild to severe illnesses. Viruses only activate inside a host cell and can affect all life forms including humans, animals, plants, and even microorganisms like bacteria and archaea. Viruses depend on the cellular system of their host for reproduction. Viruses have three main parts, which are nucleic acid, protein coat and lipid membrane. Nucleic acid is the core of a virion, which holds all the genetic information (DNA and RNA) and helps it multiply. The protein coat or capsid protects the virus by covering it and the capsid is covered by a envelope called lipid membrane. Not all viruses have the capsid and the ones that do not have the capsid known as naked viruses. Viruses are responsible for causing many plant diseases, leading to losses in crop yield and quality all around the world. Plant virology began in the 19th century when Dutch microbiologists Martinus Beijerinck and Russian researcher Dmitrii Iwanowski were investigating the cause behind a disease in tobacco (Scholthof 2001). They described an unusual agent, which caused mosaic disease in tobacco (Zaitlin 1998). There was one factor of this agent, which set it apart from other disease-causing microorganisms, and the factor was its size. It had a size smaller than all other microbes. This agent was the first...
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...bacteria includes staphylococcus and streptococcus. Vol. 4 includes a single class of Phylum Actinobacteria, in which this bacterium is a high G + C gram positive bacteria. Vol. 5 contains 9 Phyla in which they’re all gram negative but may or may not be related. “Question 7 Answer” Zygomycota are saprophytic molds in which this fungus receives it nourishments from dead or decaying matter. This fungus is the black mold on bread. Its asexual reproduction is sporangiospores and sexual spores are large zygospores and are enclosed by a thick wall. Zygomycota can cause serious infections in immunosuppressed or diabetic individuals. The specific disease “zygomyosis” is a disease in humans that may cause damage to the fetus if pregnant. Ascomycota nick named “sac fungi” because their spores are held by sac – like appendages. Their asexual spore is easily detached from its chain and become an airborne dust, and is the cause of the viral infection pneumonia in humans. Ascomycota obtains it’s nutrients from...
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...Disease and Evolution The human body has been plagued with diseases since the beginning of time—pathogens like viruses and bacteria have made us privy to Mother Nature. As humans evolve, so do the diseases we are susceptible to. Some diseases that were once rare have become common, others have disappeared and newer, more daunting ones have emerged. Many of these changes have taken place in the wake of important transformations in human civilizations and ecology. It is therefore feasible to propose that diseases succeed and fail in response to humanity's advances. Natural selection is unable to provide us with perfect protection against all pathogens, because they tend to evolve much faster than humans do. E. coli, for example, with its rapid rates of reproduction, has as much opportunity for mutation and selection in one day as humanity gets in a millennium. And our defenses, whether natural or artificial, make for potent selection forces. Pathogens either quickly evolve a counter defense or become extinct. Diseases such as AIDS, Ebola, Polio have shown their wrath and humans have sought to find cures and treatment options. By definition, disease is essentially “a disorder of structure or function that produces specific signs or symptoms or that affect a specific location (not just from a physical injury)” (WHO, 2007). The true boundaries and limitations of disease remain elusive. Healthcare specialists and researchers use “normal” conditions as their basis in order to understand...
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...the citizens. So why would we not have vaccinations be a mandatory thing if all it can cause is better quality of life for everyone? Not only do vaccines provide a better quality of life for us but they keep our loved ones, families,friends,and even our neighbors safe as well. Currently in third world countries there are mass epidemics of diseases. Why? Most of these countries don’t have vaccines available like we do in the united states yet, some of our community members aren’t using them and contracting many disease that could potentially harm themselves and our youth that can’t be vaccinated yet. Vaccinations should be mandatory because it puts the community in jeopardy, not only that but helps the government and also the hard working taxpayers save money , but more importantly it protects future generations from coming in contact with horrendous diseases . Not being vaccinated will result...
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...from a dangerous disease. It is really painful knowing that person will never get to live to see their full potential and experience life. Diseases cause many deaths every year, it is inevitable. Bacteria are contained in every disease and one way it is absorbed is by being inhaled by the people, which will infect the body as a whole. It is really simple in that bacteria will continue to live freely and happily while the host will have to suffer the effects of it. Some diseases are caused by viruses. A virus is basically a non-living infection that attacks the immune system and tries infecting other living cells. Children are much more vulnerable to diseases compared to adults because of the fact that their immune systems is still developing. Children are weak because they haven’t lived life long enough to gain immunity to diseases. So how could children protect themselves from diseases one may ask? Taking vaccination early will not only protect you from diseases, but greatly improve your immune system to counter all the other diseases. The invention of medical immunizations has not only been used to heal from the disease, but also to keep the spread of disease low. Having immunizations available have greatly lowered the amount of deaths in the world. Vaccination should continue to stay mandatory because it keeps diseases from spreading and eventually killing everyone. Bacteria and viruses infect humans in many different ways. Breathing in bacteria and viruses is one way. This...
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...Ebola and Influenza are two of the most deadly viral diseases; both diseases come from viruses that can have a detrimental effect to the human body. The modes of transmission and spread of the viruses are what make it most dangerous. According to the World Health Organisation (2012) Ebola has an extremely high fatality rate of 25 – 90% and Influenza kills between 250,000 and 500,000 people each year. Even though these two viral diseases share many similarities they differ on the type & structure of the virus itself as well as their modes of transmission and symptoms. Due to its extremely high fatality rate, Ebola is regarded as being the more lethal of the two. Ebola virus disease is a viral disease “caused by a virus of the family, Filoviridae,...
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...DEADLY DISEASES AMONG US (Science Education NIH Supplement) 1. What disease do you think is the greatest threat to students in this class? Why do you believe that? What disease do you think is the greatest threat to the world’s population? Why do you believe that? Influenza would have to be the greatest threat. This disease is very resilient and even with a vaccine; society is still susceptible to getting infected. The disease has been given a specific time of year where it can be acquired. I feel cancer is the world’s greatest threat to the population. The disease has no known cause and no clear cut cure. By not having an identifiable cause the disease is very dangerous because society have no idea as to what avoid or what to do to prevent it. Even with all the foundations in cancer research, scientist still know very little about cancer. 2. Take the quiz on some past and current causes of death and illness (scroll down for quiz). I do not expect you to know the answers to these questions, but make well-reasoned guesses based on what you do know. 3. The quiz emphasized the impact of infectious diseases on people’s health and well-being. Even though medical advances in the last century have resulted in far fewer deaths from infectious diseases than at any other time in history, those diseases are still the leading cause of death worldwide and the third leading cause of death in the United States. In this activity you will learn about some infectious diseases that cause...
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...ever do! Not washing your hands properly can cause you, or someone else to get very sick, or even die. How would you feel if someone you know or love died because of someone else not taking the time to wash their hands properly? Most people are unaware of the importance of washing their hands. Many infectious diseases are spread through direct or indirect contact. During my studies as an Emergency Medical Technician I learned the true importance of always washing your hands properly. Keeping your hands clean can prevent the chance of spreading diseases. According to a study conducted by the American Society of Microbiology, most people do not wash their hands as often as they say they do. This study found that 97 percent of females and 92 percent of males say that they wash their hand regularly. However, only 75 percent of females and 58 percent of males are actually washing their hands as much as they should. Just because you can’t see germs, it does not mean they are not there. Bacteria and viruses are microscopic organisms that can be transmitted via your hands. Germs can be passed through direct or indirect contact. Direct contact is inhaling someone else’s illness through their coughs and sneezes. Indirect contact occurs when you touch a germy surface like a door handle and then touch your nose, eyes, mouth, or someone else’s hands. Viruses can live on hard surfaces for days, to even weeks just waiting to be touched and spread. One of the most common viruses that...
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...Cause and spread of infection 1.1. Identify the differences between bacteria, viruses, fungi and parasites All 4 are different types of pathogens Bacteria is a single celled organism that multiply by themselves. They lives within and on most living and nonliving things. The majority of bacteria’s are harmless and beneficial to the human body but some can cause infectious diseases. A bacterium usually affects one part of the body and doesn’t spread across or through the body. Bacterial infections are normally treated with a cause of antibiotics. Viruses: are made up of genes and proteins that spread throughout the body by invading the body’s own cells so they can reproduce and multiply in the body. They use the body’s cells as a host because they are unable to multiply on their own. They are normally spread directly from human to human. Viruses can be very tough and there are not many effective medicines available for viral diseases. There are currently 21 families of viruses known to cause disease in humans. Fungi: like to grow in warm, moist places. Some fungi can be beneficial to us such as penicillin, but certain types of fungi can be harmful to our health. Like bacteria and viruses, some fungi can act as pathogens. Human fungal diseases can occur due to infection or fungal toxins. Symptoms for fungal diseases can be as common as itching, coughing, fever, wheezing, but they can also be as serious as meningitis or even death Parasites are organisms that use other...
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...V. Racaniello page 1 Viral Pathogenesis This lecture will define and discuss the basic principles of viral pathogenesis, the entire process by which viruses cause disease. Viral disease is a sum of the effects on the host of virus replication and of the immune response. Interest in viral pathogenesis stems from the desire to treat or eliminate viral diseases that affect humans. This goal is achieved in part by identifying the viral and host genes that influence the production of disease. Progress in understanding the molecular basis of viral pathogenesis comes largely from studies of animal models. The mouse has become a particularly fruitful host for studying viral pathogenesis because the genome of this animal can be manipulated readily. In some cases, non-human hosts can be infected with the same viruses that infect humans, but close relatives of human viruses must often be used. Viral Entry Three requirements must be satisfied to ensure successful infection in an individual host: • Sufficient virus must be available to initiate infection • Cells at the site of infection must be accessible, susceptible, and permissive for the virus • Local host anti-viral defense systems must be absent or initially ineffective. To infect its host, a virus must first enter cells at a body surface. Common sites of entry include the mucosal linings of the respiratory, alimentary, and urogenital tracts, the outer surface of the eye (conjunctival membranes or cornea), and the skin (Fig. 1). Figure...
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...amounts of diseases all over the world. In the present time, these diseases are cured or contained by vaccines. A couple centuries ago, doctor Edward Jenner developed the first vaccine in 1796. He discovered this vaccine by observing his ambiance. Jenner realized that milkmaids (tend to cattle) frequently contracted cowpox, but after they convalesced they were immune to the deadlier disease smallpox. So Jenner said, “Why not infect people with cowpox to confer immunity to the more dangerous disease.” With his research, he got the pus from a milkmaid who had cowpox and put it on a small healthy eight-year-old boys cut. Eventually, the boy was infected with cowpox, how Jenner predicted. When he was done recovering, Jenner took the riskiest step there is. Jenner deliberately injected the smallpox disease into the kid. This was a dangerous step because smallpox resulted in thousands of deaths every year or left the person disfigured. Thankfully, the boy...
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...In this essay I will be analysing micro organisms and disease. Firstly I will be defining micro organisms and then explaining the key features of the main categories of microorganisms. Followed by the roles of commensals and pathogens I will then go on to explain how micro organisms are transmitted and the routes of entry to and exit from the human body of micro organisms. I will also be explaining the logical sequence of events that occur from entry of a micro-organism to the body to the appearance of symptoms of a disease and then go onto discuss why not all infections lead to a disease. Finally I will explain a logical sequence the signs, symptoms and treatments of yellow fever which is an infectious disease. Micro organisms are living organisms (such as bacteria, fungi, viruses) which are too small to even be seen with the naked eye but visible under a microscope also named microbe. There are five types of living micro organisms these are bacteria, viruses, fungi, protozoa and algae. Microorganisms are widespread in nature and are beneficial to life, but some can cause serious harm. They can be divided into six major types: bacteria, archaea, fungi, protozoa, algae, and viruses. Bacteria are unicellular organisms. The cells are described as prokaryotic because they lack a nucleus. They exist in four major shapes: bacillus (rod shape), coccus (spherical shape), spirilla (spiral shape), and vibrio (curved shape). Most bacteria have a peptidoglycan cell wall they divide...
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...Microbiology: the study viruses and microscopic organisms I. Importance of Microbiology A. Different areas of study 1. Medical 2. Pharmaceutical 3. Industrial 4. Biotechnology 5. Food and dairy processing 6. Agriculture 7. Environmental B. Microorganisms are an important part of the human environment and health. C. Study of microorganisms brings insight into life processes in all forms of life. II. Viruses A. Not considered a live organism because: 1. Not a cell 2. Replicate by invading a cell, and using the cell to make more viruses 3. Do not grow 4. No homeostasis 5. Do not metabolize B. Structure – composed of: 1. Capsid or protein coat. 2. Some have an envelope (membrane) 3. Nucleic acid – either: RNA, DNA C. Size 1. About 20 nanometers to 250 nm (.0000000020m) in size 2. Can only be seen with electron microscope 3. Approximately 1000 times smaller than a bacteria D. Shapes E. Life Cycle 1. Viral DNA must invade a living cell to replicate a. Plant cell – through injury in cell wall b. Animal cell – punch hole or endocytosis c. Virus – restricted to one cell. 2. may go through one or both life cycles. a. Lytic life cycle - Attaches and injects DNA. - Replicate viral DNA. - Forms complete viruses. - Viruses fill cell, breaks open, and they spread b. Lysogenic life cycle - Does not make new virus. - Viral DNA injected, and makes modified DNA called a viroid. - A bacterium replicates many times. - Does not...
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...Shots, inoculations, vaccines, do children need them? This is the issue that needs to be discussed. Why are vaccines a necessity of current times? Even though vaccines may have some side effects, they have saved many lives as everyone already knows. They prevent many types of diseases and stop the spread of others. Just image having to send your children to school that’s filled with other children carrying diseases and viruses. Viruses such as small pox, measles, and mumps that could invade your child’s body which in most circumstances will then be brought home and spread to other family members. Therefore, every child in America needs to be vaccinated before beginning school because vaccines can prevent disease, save lives, and alleviate sick days at school. Firstly, many of these contagious diseases in children are preventable. Many of the viruses that cause diseases such as measles, mumps, or small pox are very dangerous. Sometimes the symptoms are very mild or not even noticed. While other times the symptoms can be severe, possibly even leaving a residual effect. For example, as everyone knows, if an adult male contracts mumps, this may cause sterility. Another example is polio, although preventable, once this disease is contracted it can lead to permanent muscle weakness. Once someone contracts one of these types of disease, it can possibly be fatal. Fortunately, these types of diseases are now avoidable thanks to vaccines. All of these viruses and more now have an enemy,...
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...one-hundred percent effective” (Daley). Even with risks, would it not be best to do something that has saved millions of lives. Every parent wants what is best for his or her child and by taking a couple of doctor-recommended shots every year, parents can help protect their children. If every parent made sure that their child was vaccinated, then maybe one day diseases could be eradicated. Vaccinating children and teenagers is important because it can help give them a healthy life, it is safe, and it can save lives. Many people, mainly parents, believe that vaccines cause more harm than good. They think that shots can damage or even destroy the immune system of a child...
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