Topic 3 - Infection and response Flashcards
What is bacteria?
• Very small cell which rapidly reproduces in your body and produces toxins that make you feel ill by damaging your cells and tissues
What is a virus?
- They are NOT cells
- They live inside your cells and rapidly reproduce causing cells to eventually burst
- It is cell damage that makes you fell ill
What is a protist?
- A single celled Eukaryota
* Parasites are an example of protist. They are carried by a vector (eg mosquito for malaria)
What is a fungus?
- Some are single cells
- Some are bodies made up of hyphae
- Cause damage by penetrating the surface of your skin or plant surface
What are the three main ways pathogens are spread?
- Water (eg cholera)
- Air (eg influenza)
- Direct contact (eg athlete’s foot)
What is measles? (Type, symptoms, prevented)
- Type - Virus
- Symptoms - Rash, fever, can lead to pneumonia or encephalitis,
- Prevention - Most children are vaccinated
What is HIV? (Type, symptoms, transferred, treated)
- Type - Virus
- Symptoms - Initially flu like symptoms, many years later weakened immune system, can develop into AIDs
- Transferred - Exchange in bodily fluids (eg blood or sexual fluid)
- Treated - Antiretroviral drugs
What is tobacco mosaic virus? (Type, symptoms and effect)
- Type - Virus
- Symptoms - Mosaic patterns on leaves and discoloration
- Effect - Limited photosynthesis and stunted growth
What is malaria? (Type, symptoms, transferred, prevented)
- Type - Protist
- Symptoms - Repeating fever
- Transferred - Mosquitoes
- Prevented - Reduce mosquito breeding, insecticides and mosquito nets
What is gonorrhoea? (Type, symptoms, transferred, treated, prevented)
- Type - Bacteria
- Symptoms - Painful urination, thick green or yellow vagina discharge
- Transferred - Unprotected sex
- Treated - Antibiotics, used to be penicillin however many strains have become resistant
- Prevented - Condoms
What is salmonella? (Type, symptoms, transferred, prevented)
- Type - Bacteria
- Symptoms - Fever, stomach cramps, vomiting, diarrhoea
- Transferred - Eating contaminated food ie raw chicken, egs
- Prevented - Most UK poultry is given a vaccine for it
What is rose black spot? (Type, symptoms, transferred, treated)
- Type - Fungus
- Symptoms - Purple or black spots on leaves that cause them to yellow and drop off
- Transferred - Spreads through wind or water
- Treated - Fungicide or striping effected leaves
What four ways can disease be reduced or prevented?
- Being hygienic
- Destroying vectors
- Isolating infected individuals
- Vaccinations
What is a pathogen?
• A microorganism that enter the body and causes communicable diseases in plants and humans
What are the three main ways your immune system attacks pathogens?
- Phagocytes engulf white blood cells
- Lymphocytes produce antibodies
- Immune system produces antitoxins which counteract toxins by invading bacteria
How do antibodies fight disease?
- B-lymphocytes produce proteins called antibodies
- All pathogens have unique antigens on their surface
- White blood cells produce the specific antigens that lock onto the bacterium or virus so they can be destroyed by other white blood cells
How is the skin designed to prevent disease?
- It acts as a barrier
* Secretes antimicrobial substances
How is the nose designed to prevent disease?
• Hairs and mucus trap particles that could contain pathogens
How are the trachea and bronchi designed to prevent diseases?
- Secretes mucus to rap pathogens
* Lined with cilia to waft mucus up to the back of the throat where it can be swallowed
How is the stomach designed to prevented diseases?
• Produces HCl to kill pathogens
Pros of vaccinations?
- Controls and gets rid of communicable diseases
* Epidemics (big disease outbreaks) can be prevented if a lot of the population is vaccinated
Cons of vaccinations?
- Don’t always work
* Some people have bad reactions to vaccines (eg swelling, fevers, seizures)
How does a vaccination work?
• By injecting a small amount of a weakened strand of a disease into a person whose white blood cells will produce a new antibody for the disease so if they are reinfected, their body can fight of the disease
