B5 AND B6

• Pathogens can be spread through : Air, water and direct contact
• Pathogen is a microorganism which causes a disease e.g virus
• To prevent bacteria growth you can use :

  Temperature

  Antiseptic

  Antibiotic

  Disinfectant
• No bacteria growth = disinfectant killed it all
• Bigger the area = mostly all bacteria killed
• Measles - spread through droplets, symptoms - fever, red rash, blotch skin rash , treatment - vaccine
• HIV/aids - spread by sexual contact , symptoms - mid flu-like immune system affected, treatment - no cure
• Tobacco moasic virus - spread by direct contact and vectors, symptoms - discoloured moasic pattern on leaves and stunted growth, treatment - no treatment farmers grow tmv resistant crops
• Salmonella - bacteria spread - infected/uncooked meat, symptoms - develop within 8-72 hour fever, vomiting, treatment - antibiotics
• Gonorrhoea - bacteria spread - sexual contact, symptoms - green discharge pain when urinating pelvic pain , treatment - contraception method/antibiotic
• Bacterial disease on plants - bacteria spread - direct contact, symptoms - crown galls, treatment - no treatment
• Calculating effect of disinfectant and antibiotics on bacterial growth

  • Measure diameter
  • Half diameter to find radius
  • Work out the area by using pi r ^2
• Communicable disease - can spread easily from one person to another e.g flu
• Non-communicable disease - cannot spread disease from one person to another e.g arthiritis
• Malaria - disease caused by a parasitic protist that lives and feeds on other living organisms. When a person is bitten, protist enters the persons bloodstream and is carried to liver and then enters red blood cells, then bursts out of the red blood cells, causing fever and shaking is carried to another person after the bites and infected person to obtain a meal of blood
• Rose black spot - fungal disease, symptoms - purple/black spots. Leaves turn yellow and drop early so there is less photosynthesis. Spread by water / wind, treatment - chemical fungicide
• Skin

  • Produces antimicrobial secretions to destroy pathogenic bacteria
• Nose

  • Full of hairs
  • Produce sticky mucus
  • Help to trap particles in air that might contain microbes
• Airways

  • Secrete mucus trapping microbes in air
  • Lining of airways covered in hair like alia
• Stomach

  • Produces hydrochloric acid
  • Destroy microbes in mucus, mucus produced to protect stomach walls
  • Destroys most pathogens
  • Breaks down protein- lowers stomach ph
  • Secrete 3 litres of HCA
• Immune system

  • Produces antibodies by white blood cell called lympocytes
  • They produce antibodies rapidly if pathogen infects you
  • Antibodies can bind to pathogens and damage or destroy them
  • White blood cell engulf pathogen and produce antitoxins
• Nitrate is need to convert sugars to protein. Deficiency - plant will not grow properly - stunted growth
• Magnesium - Need to make chlorophyll. Deficiency - Leaves are yellow so less photosynthesis so less growth
• Physical plant defences

  • Cell walls
  • Tough waxy cuticle on leaves
  • Layers of dead cells around stems
  • Cell walls strengthen plant to resist invasion by microorganisms
  • Tough waxy cuticle acts as barrier to pathogens
  • Bark on trees and layer of dead cells form protective layer hard for pathogens to penetrate
  • When dead cells are lost or shed, pathogens fall off with them
• Chemical plant defences

  • Antibacterial chemicals
  • Poisons e.g. hypericum
  • Poisons to deter herbivores e.g. foxgloves, yew, deadly nightshade
• Mechanical plant defences

  Leaves drooping or curls when touched Dislodges insects or scares larger herbivores
• Mechanical

  
  

  Mimicry -

  • Drooping leaves so they look unhealthy
  • Spots on leaves look like caterpillar eggs

  Hairs -

  
  

  Detect herbivores and not nice to eat e.g lamb ears

  
  

  Thorns-

  
  

  Detects herbivores as not nice to eat e.g cacti
• Vaccination - dead or inactive form of pathogen are used to make vaccine
• Antigen in vaccine stimulate your white blood cell into making antibodies. The antibodies destroy the antigen with risk of you getting the diseaSE
• You are immune to future infections by pathogen. Because your body can respond rapidly and make correct antibody as if u had the disease already
• Herd immunity - if large population of population is immune to disease that is spread of a pathogen will be very much reduced and disease may even disappear
• Antibiotics only treat bacteria and not virus
• Vaccination prevents infection becuase white blood cells produce antibodies these antibodies produce rapidly so they kill the bacteria
• Fleming discovered penicllin
• Willow trees create aspirin (Anti-inflammatory) also painkiller

  Foxglove create digitalis (Heart stimulant)

  Poppy create morphine - painkiller
• Required practical

  Clean ur area with antiseptics to kill bacteria

  Divide your plate into 4 sections : A,B,C and d

  spread bacteria with sterilised loop across agar jelly

  Put paper disc into each disinfectant

  Pit each disc one by one into each section of divided section

  Sterilise tools in between

  Secure the lid of plate with pieces of tape and incubate the plate at optimum temperature so no microbes can get into plate affecting growth of bacteria
• Pathogen cause disease by : Producing toxins that damage tissue

  Replicating them selves or reproducing if its a virus
• Potassium - for healthy flower and fruit , deficiency - poor growth of fruit and flowers

  Phosphates - for healthy roots , deficiency - poor root growth and younger leaves look purple
• Process of making antibodies

  Antigen is injected into mouse

  B lymphocytes make specific antibodies but do not divide

  Produces mouse lymphocytes

  Tumour cells that do not make antibodies but divide

  A hybridoma cell makes specific antibodies and divides

  Then cells are cloned

  Monoclonal antibodies are separated, purified and can be used
• Monoclonal antibodies are used for diagnosis in pregnancy tests

  In labs to measure levels of hormones and other chemical in blood to detect pathogens for research

  To identify or locate specific molecules in tissue or cells