biology infectious diseases

• What are diseases?

  A condition that causes the body to function less effectively. It also produces specific signs and symptoms
• State 2 differences between infectious and non-infectious diseases

  1. Infectious diseases can be spread from one person to another but non-infectious cannot.
  2. Infectious diseases are caused by pathogens but non-infectious diseases are not.
• How are infectious diseases spread?

  1. Through droplets in the air

  2. Direct contact

  3. Contaminated food and water
• Infectious diseases are spread through direct contact by exchanging bodily fluids during sexual intercourse and/or transmitted from mother to baby through breastfeeding and/or when the bloodstream of an uninfected person comes into contact with blood from an infected person
• What are some methods to prevent and control the spread of water-borne and food-borne diseases?

  1. having good personal hygiene
  2. practice hygienic food preparation and storage
  3. maintaining a clean water supply
• How is influenza transmitted?

  through droplets in the air, a person touching an object or surface contaminated with the influenza virus and touches their mouth, nose and eyes
• What causes influenza?

  influenza virus
• state the signs and symptoms of influenza: high fever, headache, sore throat, cough, muscle aches, stuffy nose
• How to reduce the transmission of the influenza virus?

  1. get the influenza vaccine
  2. avoid close contact with those with the virus
  3. wash hands with soap and water
  4. take antiviral drugs prescribed by the doctor
• What causes pneumococcal disease?

  pneumococcus bacteria
• True or false

  Pneumococcal disease is transmitted through respiratory droplets?

  True
• State the signs and symptoms of pneumococcal disease

  fever, headache, vomiting, cough, chest pain and rapid breathing
• True or false

  Taking antibiotics can reduce the transmission of pneumococcal disease

  True
• Define Vaccines.

  Vaccines contain an agent that resembles a pathogen and prevents infectious diseases by stimulating white blood cells to quickly produce antibodies when the pathogen invades
• Explain step by step on how vaccine works

  1. White blood cells binds to the agent
  2. White blood cells are stimulated to divide
  3. White blood cells produce antibodies
  4. Antibodies produced destroys the agent in the vaccine and some white blood cells and antibodies remain on standby
• Why do some white blood cells and antibodies produced remain in the bloodstream?

  If live pathogens were to enter the bloodstream, the white blood cells would already recognize them and quickly produce antibodies to destroy the pathogen before they can infect other cells.
• Define Antibiotics.

  Antibiotics are drugs used to treat bacterial infections. They are made by microorganisms and are used to kill the growth of bacteria.
• True or false

  Antibiotics work on viruses

  False
• Why do antibiotics kill bacteria but not viruses?

  Antibiotics weaken bacterial cell wall and water enters via osmosis causing the bacteria to swell and burst. Antibiotics inhibits some enzymes therefore inhibiting the growth of bacteria. Antibiotics prevent ribosomes from making proteins+enzymes therefore the bacteria cannot survive thus dying. Antibiotics also breaks up bacterial cell membranes (PPM) and without them, any substance can go in and out of the cell.
• What does antibiotic target that makes it ineffective on viruses?

  cell wall, cell membrane, ribosomes and enzymes
• True or false

  Viruses contain cell membrane, cell wall and ribosomes.

  False
• What are superbugs?

  Bacteria that are resistant to medicines such as antibiotics
• Explain why a patient would need to complete a full course of antibiotics.

  initial doses of Antibiotic X would kill the more sensitive bacterial cells but the less sensitive would not be killed easily and may survive. If the antibiotic course is completed, there is a high chance that all the bacterial cells are killed. HOWEVER, if the antibiotic course is not completed, the less sensitive bacteria that survives would multiply and increase in number. Therefore, developing antibiotic resistance and the patient would need new and stronger antibiotics.
• State 3 ways to reduce antibiotic resistance - not misusing antibiotics, completing the full course and only using antibiotics when necessary