Health and disease

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some example disease? Pathogen. to an organism causing disease to its hest lusually microorganions) 4 groups. bactenä vious and true organisms. -protest -fungs 1) 1 symptom of: a tubercution's- coughing up blood, night sweats 6) cholera- diarrhoed, nausea / 13/12/2022 2) Chalara ash dieback infects"" "trees/ ash Ebola-blood vessels, liver, kidney cell damage Chalara die back F✓ AIDS V Stomach ulcer B✓ Ebola V✓ Tuberculons B b) one symption of chalara is black blotches on leaves. 1) Malaria P/ 2) These diseases are a communicable because they are caused by pathogen. and therefore can be spread.✓ 3) HIV infections Weaken the immune system, and therefore the body is easier to be caused illness by pathogens. The white blood cells cannot fight the pathegen.. Disease chalara ash dieback Malaria mosquitos are the vectors) Ebola Heliabacher pylon Tubercules's cherera Athletes jest, падисти, Pathogen type (bacteria, virus, fungi, protist) fungi viruf Protist virus bacteria bactenu bacteria репері Organism it affects (human or non-human) non-human human both питан питан human питан Symptoms (pick 3) -black blotches on leaves - small lesions on sterks extensive dieback of growth. shaking culills -high fever headache pain high temperature - hemorrhaging aches and pein -weakness + fatigue -gastrointestinal -No symptoms/ wker's in stemach lining blood Coughing night fireals weight loss -diawherea -nausea -hausen - vomiting -abdominal ramining наку -sove peaky patches Litcy red skin -cracked feet - itchy skin -newrless. ∙red scarly cracker Disease SARS flu HIV COVID 19 cold Pathogen type (bacteria, virus, fungi, protist) rivus vous viny virus virus Organism it affects (human or non-human) питам human пител питан human Symptoms (pick 3) -high temperature extreme tiredness - chills -headaches -muscle pain -fever / chills -body aches 1-weakness -develops AIDS -suceptible to other disease -secondary illnesses -high temp -cough -headaches -minny nose пипу -stuffy nere 1-coughing dieback Chalara ash fungi fungi, protist) (bacteria, virus, Pathogen type non-human Disease small lesions extensive dieback of growth -black blotches on leaves on sterks non-human) affects (human or Organism it Symptoms (pick 3) Spreading Pathegens Her are pathogens spread? 16.12.2021 - Pathogen an organism causing disease to its Symptom. the manifestation of a disease in an organitur something that is suffered when an organism is ill. Openity. when a person has a dangerous level of four in their bedy. Someone overweight for their height BM1 730 Communicable disease spread from persen. person caused by a pathogen. fo Non-Communicable disease. can't be spread from person to person, not caused by a pathegen. Mental well-being the state of being content. your own brain how you feel about yourself. and healthy M Food and water - more common in less developed counmes -oral route -not washing hands after 100 = oral- faecal transmissions E -bachena spread on flies feet -Cholera · backria (food / water) -heroums-virus (food) - salmonella-bacteria (food (water) - E. Coli-bachena ( food / water) Typhoid-backena (food (water) -Dysentery backena (food / water) Touching foreces - faecal-oval route - if hands are not cleaned, top is touched and eaten, pathogens from faeces in yours -E. Coli-bachena (internines of animals contaminated food + water) "-Cholera-bachena (contaminated food (water) -Hepahtis A + E-V (faces of infected personl SPREAD OF PATHOGENS 분 biohazard mother to child -Syphilis/HIV able to cross placenta + onfect the baby in the uterus. M7B in childhood-> generhoea, Chlamydia, hepah's B, genital herpes - HIV-virus (blood, semen, laginal, fluid, breastmak) -chlamydia - bachenal come, rectum, throat, urethra) • generhoea-bacheria (semen, vaginal fluid) genital herpes virus ( cemx, vagina, vulva) -Syphilis bachena (seves) -Hepaliti's B- vines (blood, semen, raginal fluid) -cat-virus - Flue-virus -Tibacteria- COVIDIa-virus -Calava ash dieback- fungi A single sheeze 100mph, 40,000 dropleks Sft radius Needles and medical equipment • transfer of blood - blood berne infections drugs, needles, syringes (and trattars) HIV- vimus ( blood, semen, & fluid, breastmain) Hepahn's B and C-virus (blood, semen, & fund) -diabetics who reuse ishin needles Ajr sending droplets into the all -gold + flie can survive a day in r. TB bacteria Months insects -some pathogens cannot survive, have to spread in other ways. → -Malana - protist (mosquito in bised). Dengue-virus (mosquitur) -Lyme disease-bacteria (ticks) -West Nile virus (mosquito) -Plague-bacteria (Hea) "Direct contact (bodily fluids). physical contact Gtouching, Kissing, sexual contact. contact with oral secretions or cuts. For example. -HIV virus (blood, semen, V fluid, breastmica) - Chicken pox vivus (shin or mucous membrane) Cold soves (herpes). virus (skin or mucous membrane) conjunchvitis-bachena eskin or mucous membrane) -Hepann's B+ C-virus (blood, semen, vplied) •Ebola- virus (blood and other bodily. fluids) Vinio life cycles What are the two life cycles of a nivus? hysis-cell membrane is broken open and everything. innde is released. viruses 4 1 2023 - smallest of the pathogens. ·consist of a single/ double stranded nucleic acid, surrounded by protein shell (capsid) - some have an oncer+ envelope composed of lipids+ proteins. -2 classes-RNA, ONA RNA vibose sugar, phosphate groups & hares ONA decay rivese sugar, phosphater group joined by bases. vivuses that take over human cells- HIV/ Ebola immune system tries to get vid, vions evolves. co-evolving. -Pheloviruses can replicate a billion times. - spread through bodily fluids? air droplets, blood. Lytic Cycle + Lysogenic cycle bacanal chromosome Cell lyses. reasing viruses virus amammas to and injects genetic ma viral genetic material Lytic cycle Viral genetic material forms a circle New viral genatic material and proteins are produced and assembled copies viral genetic material Lytic pathway- vivus enters and takes over Lysogenic sync genetic Occasionally the viral genet bacterial chrome causing a lyc cycle Lysogenic cycle start Viral genetic material inserts itself into the bacterial chromosome Call ad vi gorac the cells replication process to produce more viruses and causes lysis of the cell as new vivuses are released. Bacterium reproduces normally replicating veral genetic material at each cell division Lypugemal cycle- the pathway where the lines genetic material unserts into the cells genetic material and is replicated each time the cell divider. 1) in the lybic cycle, the virus enters and buller over the cell's replication process to produce mere vinuses and causes. lysis of the cell as new houses are released (the cell membrane is broken down) ✓ 2) in the lyrogenic cycle, the wis genetic material inserts into the genetic makenal and is replicated. each time the cell divider. Occasionally, the ninal genetic markenal separates and curses it to enter one lysic cycle. 3) hysis means when the cell membrane is lovoken and everything inside is releated Viruses cannot sumire in their win, they have to attach to bacterial cells Therefore they. I are not dassed as trive thing. organisms unable of reproduce in their own (Mrs trens) 01. Measies is a disease caused by a virus Describe the lytic pathway for a vins in the listic pathway, the virus attached to the cell and injects generic material viral generic material forms a circle. As the cell replicates, new viral geneht material and proteins are produced. The cell lyses ( the cell membrane is broken open + everything inside is released) -take over host cell machinery Plant Defenser How do plants protect themsdres wring physical and chemical submances? Pest- organisms which cause problems Plant defenses perseng thems - пиписку mechanical hours physical cellulose cell wall. tough waxy cuticle difficult for -trees have thick bark get throu Signin chemicals thoms (rose) -anti-microbial chevnicals. -persons (foxglove / nettles) & deters herbivores --mimicry & trick animals. -drooping rook's time butterfly Giess by 0 a- The outermost layer of the leaf that pathogens must get through is called the cuticle. eggs unely to be caben lalvåe 6- The thick structure around every plant cell that pathogens must get through is called Balisade cell tamtek. cellulose cell wall, <- claer trees have structures that pathogens must get through that are thicker than younger; therefore it is harder for them to get through. young ash trees are more likely to be infected due to their weaker protective structures eg. cellulose cell walls. Q2. A scientist was planning to compare the effectiveness of the antibiotic myxopyronin on two different species of bacteria. Figure 18 shows the equipment the scientist can use. agai plates two species of bacteria filter discs of myopyronin Figure 18 spreader incubator Infections can also be caused by viruses. Describe the lytic pathway of a virus and how this causes the spread of infection through a population. in the lyric pathway, the virus attaches to a cell and injectis genetic material. The genetic material forms a.. circle, and as new vival genetic material and proteins are produced the cell lyses/b I the... cell membrane is broken open and.. everything inside is released viruses are.. either RNA or DNA, taking over human.. cells. The immune system trips to get rid of viruses, however the virus evolves. Viruses can be spread through bodily thids... eg. air droplets or blood Examples of this are Hly and ebula Allowing spread to another host en af cells. Therefore they. wence in their own, they have to attach to organisms. unable to reproduce on their own [Mrs frant) I are not dassed as trive thing Q3. The lytic pathway is part of the lifecycle of the Ebola virus After infection of the host cell, components of the virus are produced. The genetic material of a virus can also be inserted into the genome of the host Name this type of pathway by sogenic () State what is meant by the term genome. Q4. The complete set of genes for an organism. Antibiotics have no effect on the lifecycle of viruses. Describe the lifecycle of a lytic virus. The vines attacher to Wand injects genetic makenal The vival genetic material feris a circle New Aral geneh's material and proteins are produced and assembled. The cell usses the all membrane, 5 broken orten & everything inside is released. -bucleic acid of virut moves across cell membrane -host all synthesized now viouses -release of fully assembled vihis particle 0 Plant How de submi Pest- Plant persons thems mirnic Mechani a- The outermosi called the i 6- The thick str is called pa <- claer trees Au thicker than y Young ash tree protective struc •) Physical -leaf cutide -bark -cell wall -spines -thems 1-trichemes ✓ Chemical 1-poison inside cell -toxins which act like insect repellants 2) An example of a physical banner is bark trees have a thick layer of this, called lignin. This serves as a protection. from pathergests it is harder for them to get past the surfence 3) An example of a chemical barrier is person inside the cell. For example, fox glaves and nettles have person to deter lutf herbiveres. In nettles, histamines are released. to cause inflammation and pain in th the pest. 4) plants produce chemical substances, eg nettler releasing. histamines, to deter the pest it is a protection from Ahreats damage caused by animals that eat them, P Phypical and chemical bamen What phypical and chemical bariery do we have that can help protect us? Physical bamer- a barrier that makes it difficult for parthespens to get into the body. Physical and chemical bamers. Skin mucus cha in aliated tean, saliva, miny -lysozyme -stemach acid (HCI) 1) The skill protects against infection by acting as a physical barer from pathogens It has lots of sweat glands and can regulate temperature ✓ made 2) when the skin is damaged, pus is created on the surface, up of white blood cells to prevent infection. and it also ques red which shows the blood nishing to the surface to help repair quickly blood dets (platelets) 3) When smoking or into the stomach to be waffed out thanages the cilia, mucus cannot offim body. be killed. Therefore pathogens can get into the wings causing infections due to there being no physical bamers. 1) Physical-shin, mucus, cilia 2) Chemical- lysozyme, stomach acid (HC) 3) The shin is a thick barner to protect from pathurgens, alia is little hairs that waft pathogens. STI'S What are sils and how can their spread be reduced? Secually transmitted diseases/ infections (STIS) - a communicable dicase that can be passed from an infected person to an uninfected persen during sexual activity. Question What is a light microscope used for? What is the equation to calculate total magnification? What is the equation to calculate magnification? What stain is used to see animal cells? What stain is used to see plant cells? What is an advantage of an electron Answer to increase the size of cells so we can observe them total magnification What is the role of the chloroplasts? eyepiele objective leni lens ( size of object maquired magnification real size of object methiflure blue ✓ irdine better resolukin, better magnification microscope? What is the disadvantage of an electron microscope? What is the role of site of acrobic respiration. the mitochondria? only use for dead cells whage can only be in black & What is the role of S.be of probere synthesis. the ribosome? contains chlerophyu. Sive of photosynthesis 17122 ✓ 1 sex, oral sex 2- wearing condems reduces the spread of STb is a bacterial disease. 3. Chlamydia 4 sexually active people are more likely to become infected. 5 Preventing HIV-getting tested / getting the vaccine. Chlamydia- getting antibiotics Weaving condems prevents the transmission in the first place р eyelashes and eyebrows Lysozyme - tears, saliva and mucus - helps protect thinner surfaces. C mucus is a sticky secretion. produced by cells lining the openings that pathogent could. use to enter the body eg trachea, DJ P the skin thick bamer - pathogens only cross wounds or thrindal recters. с the stomach contains stomach acid (HCI) - PH 2 -only few backena, eg Heliobacter pylen cout survive C+P wounds blood dothing quickly blocks an open wound. -causes swelling and formation. of pus as the body the pathogen attacks BS Health and Disease. STI Questions. Figure 2 shows the number of people diagnosed with sarually transmitted infections (STIs in the UK sexually transmitted infection number of people diagnosed (STI) per 1000 of the population 37 chlamycia gonorrhoea genital herpes genital warts syphilis 0.6 244 200 1.1 Figure 2 State the sexually transmited infection that has the median number of people diagnosed Chlamydia (i) The population of the UK in 2017 was 60 million people Calculate the total number of people diagnosed with chlamydia in the UK in 2017 1000 x 66,000,000 - 240 2414200 (State why chlamydia can be described as a Chlamydia is spread and caused by a pathogen (bachenal Give one way the transmission of chlamydia can be prevented mmunicable disease Weaning condems during sexual activity. for a long time after an infection or vaccine. memery lymphaytes- a lymphocytes that remains in the blood skepping of from working. Explain why chlamydia can be treated with antibiotics which will release antibodies that attack to the pathogen, surface that match the shape of the anligen on a surface, called antibodies A lymphoryhe has antibedies on White blood cells called lymphocytes have other molecules on their раморет in Chlamydia is spread via bacteria Bactend is op diseases can be gotten nid of using antiblond hoes is a sexually transmitted bacterial infection Figure 7 shows the number of people diagnosed with gonarmoea in the UK 30000 number of people diagnosed with 15000 gonorrhoea 25.000 are apt able to recognise pathogens because of their antigens. Antigens a protein on the surface of a cell. White blood cells 10000 5000 inimunity How does oux immune system help protect us from pathergens? 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 year (Total for question 7 marks) Figure 7 screening in be reduced of people infected female (Total for question = 6 marks) sexual activity and with an a pathogen, bacheria it is a sexually transmitted disease. Gonorhola is a bacterial infection meaning it is spread via infected person causes it First of all, Questions Q1. Describe how the specific immune system defends the body against disease. if Pathogens get past chemical + Physical defenses... the immune system must prevent harm. A. Tymphocyte that has an anlibody that perfectly fill the anngens on pathugune is activated. The lymphuctate divides rapidly to produce identical.. anhbodies. Some secrete large amounts of antibodies that artach to antigens and deswory (Total for question marks) the pathogen. Q2. Clostridium tetani is a bacterium that can be found in soil. It causes the infection tetanus. Children are vaccinated against tetanus. Explain why these children do not get tetanus if the bacteria enter their body through a cut in the skin. When children are vaccinated against tetanus, they are... injected with a weakened form of pathogen. "The Immune system produces lymphocytes with antibodies.. complimentary to the antigens on the bacteria's.. surface destroying them in the future, these are remaining in the blood as memory lymphocytes.. Therefuxe, if the bacteria enters the body via a break in the physical barrier, skin, the immune System prevents harm. - they are imovine. -leading to a secondary response. (3) (Total for question = 3 marks) 1912023 immunity How does own immune system help protect us far pathogens? 1) Antigen-protein on the surface of a cell white blood cells are able to recognise pathogens due to their antigens. 2) Antibody- protein produced by lymphoyber Maches to a specific antigen on a micro-organe for destroys or outraliser. 8) A lymperocyte is a white blood cell with antilasdus on its surface. that match the antigens on pathogen. 4) A phagocyte is a white blood cell that swallows pathogens, engulfing Micus-organisins such as bacteria 5) Memory cells- a lymphocyte that remains in the blood for a long time after an infection or vallination 6) Chemical defense. lysozyme. 1) An antigens is a protein on the surface of a cell-white blood alls are able to recognise pathogens due to their antigens. 2) the immune system has lymphocytes which produce antibodies. that are complimentary to the antigens on the pathogen Therefore they don't attack nemal pathegeni. 3) Only sommie lymphocytes are activated by a pathogen because. only the specific andgen lymphocties are achuated 4) The primary response takes much longer and the antibody production munibers are much larver mimurity cartinued How does our ummune system help protect us from pathogens? Antigen- a protein on the surface of a cell white blood cells are able to recognise pathogens because of their antiguers. 29 23 hitially, the pattregen must get past the skin, mucus and citia to cause an ummune respense. The antigens on the surface of the pathogens are unique to them, and the immune system recognises it as harmful Over time, a lymphouple with an antibody that perfectly fites the antigen is activated. The lymphoryle divider rapidly to produce identical repies, with the same antibodier. The antibodies attach to antigens and destroy the pathogen. Some these lymphocytes stay in the blood stream, and in case of a secondary infection. If the body is expered to the pathogen. ngjain, the body can quickly activate tre lymphoryter so that they can quickly divids and destroy the pathogen This is a aunch faster response, as the immune systern desn't have. to spend time producing antibodies. Question What is the mass of a proton? What is the mass of a neutron? Define 'atomic number' 1 number of protons in nucleus of an alum Define 'relative atomic number of protons + neutrons in nucleus of mass an alum How do you calculate the number of protons in an atom? How do you calculate the number of neutrons in an atom? Define an isotope. Answer Why do isotopes of an element have different relative atomic mass numbers? 1 Why is "Cu an isotope of "C₁₂? = alomic number Why do isotopes of an same number of protens element have the same atomic number? pass number alamic number alm of an element, same number of protoms different number of neutrons different number of neutrons same number of protens (6) different number of neutrons What is the mass of a protan? What is the mass of a neutron? Define aromic number mass s> Define relative acom How do you calculate the number of proton an atom? Now do you calculate the number of neutrons in an atom? Define an isotope. hy do hatopes of ar Yment have the ne atomic number do isotopes of a at have nt relative uan isotope 1 1 Austur at Questions Q1. Lisa was investigating the effect of three differant anebiotics on the growth of bacteria. Lisa left the Salmonella bacteria to grow on an agar piate for a week with three discs each containing a different antibintic A. B or C. The diagram shows the results of the experiment. The dark grey area shows bacterial growth The light grey area shows where the bacteria did not grow die with antibiotic A disc with antibiotic B 4mm 2mm llom bacterial growth dise with antibiotic C (Measure the width of the no bacterial growth for antibiotic A and antibiotic B Calculate the difference between the two widths no bacterial growth (a) Chemicals, other than antibiotics, can be used to prevent bacterial growth. Give the name of one of these chemicals. lysozyme X (12) fference= (a) Before the experiment Lisa predicted that: All the discs would work and no growth of Salmone would be found around the discs. Explain why this prediction was incorrect Use the results for all three antibiotics in your explanation Sie is wiong pecause the agar plate sussusds the dirks with backin 4 worked a widex anze Some growth Dish Crafters less effectue, but pressed B. • work, as it falled to...prevent growth. Antibedies Why must medicines treatment? Antibiotics - chemicals that work against bacteria Q2. MALIK scheme be tested before they can be used. Describe the response of the numan body to immunisation -lymphocytes production of anabacchier L-memory symphocybes During immunisation, a weakened form of the disease is injected. The immune system responds the... antigens on the surface of puthagen's match with anhibutier on the symphocuter produced. These are activated, and they Kin the harmful pathogens. These lymphocyter stay in the bloodstream as memory lymphocules therefore someone gels the disease later, the immune response 23. is much faster and they won't get ill. The flow diagram is about Edward Jenner's work on vaccines. Jenner collected pus containing the cowpex virus from the hand of a milkmaid antibodies -introduces an angen/ causes an immune response He put the cowpox virus into an 8-year-old boy Two weeks later he put smallcox virus into the same boy aseptic The boy did not develop smallpox Use words from the box to complete the sentences about vaccines. pathogens hormones immune The cowpox virus from the milkmaid caused the boy to become.hune. His body produced bodies which stopped the smallpox virus from causing an Infection. 271123 to smalpox. your 1) it's important to always finish the full count of cushibisher because there are different levels of restrande of the backend start the antibiotic cells. Same are early killed when course, however if you finish early your body hasn't had the chance to kill the resistant ballena because bodly has the perfect conchuzur for backenal replication, fots of resistant backra grow. This is so much harder. for your bedy to get rid of your 2) wruses aren't living organisms when they are inside the body, they wire and survive in cells Antibiotics cannot be uted to treat mouses because they would have to kill your own alls to get not. Pre-clinical teshing- on cells+ hasues small clinical trials- small number of healthy. people, checking side effects Animal testing-new mediciner on animals Madone works well Medicine has harmful effect large cinical trial. large number of people with disease, work our dose + side effects Antiseptier core practiced How do antiseplies affect mustrial cultures? A septic techniques techniques used in the laboratory to prevent contamination of microbial culture. Question What is an isotope? Why are some isotopes radioactive" What is radicactive decay? Where does radiation come from? What is the structure of alpha radiation? What is the structure of beta radiation? What is the structure of gamma radiation? Why is radioactive decay described as random? What is activity? berquerts What is the definition of half-life? Answer wen of an element with different member of neutras Tunstable nudeus, too many yuchons breakdown of a radioactive ruchope by release of alpha, bela a nucleus of an aban Melium nucleus: 2 protons, 2 prosens, 2 rections 2 high speed electron EM ware, short warelangin. high frequency can't predict when or which isclope with decay we sty roles the rate change in an hustable Mickens, measured in bequerell the time it takes for half of MULLON Sterilise petri dishes and agar in an autoclave Pour the sterile agar plates and leave it to set Add a few drops of microorganism solution to the agar, then disinfect the pipette Use a sterile spreader to spread the microorganism culture across the surface of the agar Label and turn the agar plate upside down. incubate at 25 degrees. -this will Kill Any bacteria that is present in the son or in the Petridish -Provider the selected backevia with all the humines necoed to grow. -the solution contains the backena. that will grow on the agar. - allows a lawn of backvia to the produced across the whole of the plate Stops unwanted bacteria in the air Contaminating the plate. -Den't fully close → needs aerobic respiration Msicad of anaerobic harmitul backend. •roduct; the chance of harmful pathograr - create a lawn of bacteria on agar plate, using are phc techimerk -place disk containing anh sephics. Antiseptis care practical part 2 How do antisepties affect microbial cultures? Aseptic tednique- techniques used in the laberaliry to prevent centarmination of microbial culture. 1) When doing the practical, the zone of inhibition is where the backing has been killed / -are around anreichic -no bricosure diaracter z 2) 701² to calculate zone of inhibition/ 3) - Get a petn dish and rum it upride down, draw 3 Sections on one control, and separate ones for the 2 antisephor After turning the dish up, light the bunson burer and pour open the cap of the agar bottle; pass the neck through the flame and pour it into the dish, put the lid back on, selidify in anautocare Put bacteria culture into the & agar and spread it, put on the lid quickly, leave to grow. Use forceps/ place antiseptics on and tape a cress on the lid Leave. it for 2-3 days and observe the most effective. petri dish 4)- autoclave the -pass the neck of the backnia through a flame. -mpe ethanol on the surface of working. ✓ - close the petri dish lid as much as possible. Stenlise the forceps - work next to a bunsen flame - heat rises- therefore pathogens don't fall on it. -annsephs handwash D B с Method Apparatus . . A Aim To investigate the effect of antibiotics on bacteria. ● Edexcel GCSE (9-1) Sciences E F GCSE METHOD SB5k.1 Your teacher may watch to see if you can: work safely and aseptically with microorganisms. . O Petri dish with lid screw-top bottle of sterile liquid nutrient agar (keep in water bath until needed) sterilised in an autoclave bacterial culture in screw-top bottle sterile pipette in wrapper sterile spreader in wrapper beaker of disinfectant two small filter paper discs of different antibiotic concentration or type small disc of sterile filter paper sticky tape marker pen forceps ethanol (IDA) ruler Bunsen burner and heat-resistant mat Investigating the effect of antibiotics A Safety Plates must be taped closed as in the diagram. This allows air in and does not encourage the growth of pathogenic bacteria. Pouring an agar plate Keeping the lid on the Petri dish, turn the dish upside down. Use the pen to draw three sections on the base, as shown in the diagram. Label one section 'control and the other two sections with the name or concentration of each antibiotic. Add your initials and the date near the edge of the dish. Turn the dish the right way up. Dispose of all cultures and equipment safely, at instructed by your teacher. Take care to avoid burning fingers when faning the neck of an agar bottle. Avoid touching eyes or skin after handing bacterial cultures. Wash splashes immediately with water Wash hands thoroughly before the practical and again before leaving the laboratory. Ethanol (IDA) is hazardous and highly flammable. Keep away from open flames, except as described in the method. Making a bacterial plate Remove the pipette from its wrapper and do not put it down. Unscrew the cap of the bottle of bacterial culture and quickly pass the neck of the bottle through the Bunsen flame. Draw a small amount of culture into the pipette then flame the neck of the bottle again and replace the lid Light the Bunsen burner and set it to a roaring flame. Work in a pair to pour the plate. One student should unscrew the cap of the nutrient agar bottle and quickly pass the glass neck of the bottle through the Bunsen flame, as shown in the diagram. The other student should lift the lid of the Petri dish just enough for the agar to be poured carefully into the dish. Pour in enough agar to half fill the depth of the Petri dish base. Replace the dish lid immediately. Flame the open neck of the agar bottle again before screwing the cap back on. Leave the agar to solidify Investigating the effect of antibiotics culture to the agar Replace the Unwrap the spreader and, lifting the dish id as little as possible, gently spread the culture drope across the agar using a back-and-forwards motion with the spreader. Replace the dish lid and place the spreader in disinfectant. Adding antibiotic discs K Sterilise the forceps by dipping them into ethanol then passing them through the Bunsen flame to ignite the ethanol. H Edexcel GCSE (9-1) Sciences J L M N O SB5k.1 Lifting the lid of the Petri dish as little as possible, gently add two drops dish Id and place the pipetle in disinfectant. 3 Use the forceps to pick up the sterile filter paper disc. Lift the dish lid just enough so that the forceps do not touch the bacterial layer on the agar in the dish, and carefully place the disc on the section labelled 'control". Replace the dish lid as quickly as possible. Sterilise the forceps as before (step K). Then repeat step L with one of the antibiotic dises, placing it on the appropriate section of agar. Remember to replace the dish ad as quickly as possible. Repeat step M with the other antibiotic disc Tape the lid onto your Petri dish with two pieces of tape, as shown in the top diagram on the previous last page, and invert the dish. Leave it at 20-25 °C for two to three days. P Look carefully at your dish. Do not open it. Recording your results 1 Measure the diameter of the circle around each disc where there is no bacterial growth. 2 Divide each diameter by 2 to calculate the radius () for each circle, and then calculate the area of ne bacterial growth using the formula area = ² Draw up and complete a table to record the area of no bacterial growth for each disc Considering your results/conclusions 4 Explain what your results show about the effect of antibiotics on bacteria. 5 Compare your results with those of other groups. a Did other groups get the same results? If not, suggest why not b Explain which of the discs was the most effective at killing bacteria. Evaluation 6 Suggest a way in which the method could be improved, and give a reason for your suggestion 7 a identify steps in the method that contributed to working aseptically. b Explain the importance of working aseptically in this practical. wo different sof (2) 7.2.23 spleen isolabe. nenadenal antibodies How are menochenal antibodies produced using hipon dema. cells? menotimal antibodies- many identical antibodies sotrovimal -synthetic proteins which sticks to coronarious to prevent an infection cut their risk of hespital admision and death by 79% hyblondema alls - a cell made by fusing a lymphocyte and a cancer cell. @How are metrolaral antibodier produced? Produced in labs from identical immune cells. Meuse vacinated with antibodies & cells in the speen are produced isolates the cells and fused with cancer cells to make hybnouma cells. Ⓒ What can they be used fer? -Locate blood dets Recognise and bind to antigens Diugnesing+ treating disease. Pregnancy tests (HCG in wrine) Anh cancer- only reach canter. special markey's for cancer @ What are the disadvantager of menodonal antibodies Expensive, and hipreconsuming too specific, a more direct and diverse bype would be better Also lots of side effects that aren't expected.