This relates to Big Idea 1: The process of evolution drives the diversity and unity of life. On pgs. 125-126, Dr. Moalme refers to the first use of a vaccination as discovered by Edward Jenner, an eighteenth century doctor from Gloucestershire, England. Jenner noticed that milkmaids who caught cow pox, a very mild infection in humans, would become resistant to small pox, a very deadly infection in humans. Jenner replicated this and infected several others with cow pox. In the end, those effected also became resistant to small pox and Jenner had discovered the first vaccine.
Explain how a vaccine works, and how it allows organisms to survive and reproduce. Research another vaccination along with its corresponding disease and explain how the vaccination works to create a resistance towards that disease. In addition, since there are incredible numbers of potential microbial attackers and only one specific antibody produced from our bodies can fight that specific attacker, how are our genes able to produce enough antibodies to fight the countless microbial attackers. Using pgs 126-134, with emphasis on pgs 132-133, explain how our bodies are able to fight back against the countless microbial attackers. Finally, using information from Unit 1:Evolution, explain how this advantage allows for humans to survive and reproduce.
Posted by Weilly Tong (wtong4@students.d125.org)
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ReplyDeleteAs discussed on page 126, a vaccine is a harmless version of a virus that the body wants to be protected against. A harmless version of a virus would be either a weakened virus, killed virus, broken up virus, or a weaker virus that is very similar to the more dangerous one (like in the example of cow pox being a vaccine against small pox). With the injection of a vaccine into the body, immune responses are activated and antibodies are made from B lymphocyte cells to match the antigens on the weakened virus. These antibodies are specifically made to attack and kill that specific virus with those specific antigens. After the B cells with the antibodies that are specific to the virus’ antigens, memory B cells are made to remember to shape of the antibodies to use in case of a future attack of that virus. With an immune system already full of antibodies for the more dangerous virus, when that more dangerous virus invades the body, there will already be a set of antibodies made from memory B cells, ready to destroy the virus. If the body can kill viruses more quickly and earlier before they spread too far, organisms live longer to survive and reproduce.
ReplyDeleteInfluenza, a viral infection, is a very common invader during certain seasons throughout the year. Each year, new influenza vaccines are made because the antigens on the surface of influenza tend to change a little each year, thus the need for a new vaccine is called upon. The proteins, or antigens, on influenza are the haemagglutinin (H) and the neuraminidase (N). There are different types of H and N and different combinations of the two proteins are found each year with the new influenza virus. Flu vaccines are used to create specific antibodies for the new version of the flu each year. Since the antigens change each year, the antibodies need to be made again to fit the new shapes of the antigens. A couple weeks after vaccination, the human body will have created antibodies for the influenza virus. If that person with the flu vaccine gets the virus in their body, the infection can be quickly destroyed as the body already has the antibodies to fight it.
http://www.virtualmedicalcentre.com/treatment/influenza-vaccine-flu-vaccine/155#c2
As it says on pages 132-133, our genes are able to create so many different antibodies to fit all the different, specific antigens that our bodies encounter because each of our genes don’t just create one protein. One gene in our body can make a great variety of different proteins because of variety in mRNA copying, splicing, and post-transcriptional processing of mRNA. Genes can always rearrange themselves to make different proteins in the body. Even with each gene having the ability to create an array of different proteins, the genome system is not 100% dependent on each gene to create those specific proteins only. The system is good at reacting to change, like if a gene were to be removed or replaced. Clearly, with a system of genes that can create a myriad of proteins for the body, enough antibodies can be made for all the various infections and pathogens that may invade our bodies. All those proteins can make different types of lymphocyte cells, B or T cells, which are necessary in the immune response to microbial attackers. The use of antibodies in our immune systems allows us to survive and reproduce because the immune system try to kill as many pathogens that enter our body as they can in order for us to live longer. As we live longer, we have more time to reproduce, giving offspring our genes to carry on to future generations.
(Jenny S. Li - jesli4@students.d125.org)