B5 Infection and response Flashcards
What is health
A state of physical and mental wellbeing, not just an absence of disease
What is a communicable disease
An infectious disease caused by pathogens
What is a non-communicable disease
A disease that is not infectious
What factors affect health
Diet
Stress
Life situations e.g gender, ethnic group
What is a pathogen
A bacterium, virus, or other microorganisms that cause infectious disease in living things, including plants
What are bacteria
Single-celled organisms that reproduce by binary fission
Environmental decomposers
Pathogenic bacteria are the minority
What do bacteria do
Cause the majority of communicable diseases
May produce toxins
May directly damage cells
What do viruses do
Cause disease in every type of organism
What are viruses
Small, regularly-shaped pathogens that live and reproduce in cells, damaging and destroying them
How are pathogens spread
Droplets
Direct contact
Water
What do bacteria need to grow
Culture medium (carbohydrates - energy, nitrogen - protein production)
Warmth (some)
Oxygen (some)
How should petri dishes be stored
Upside down to stop condensation dripping
Why should petri dishes be partially secured with tape
Stops air from contaminating bacteria and vice versa
Stops the growth of anaerobic bacteria
In school labs, at what temperature should bacteria be stored
25C and under
In school labs, why is there a limit on the temperature that bacteria can be stored
Reduces the risk of pathogens growing
What is an antiseptic
A substance used on living surfaces to destroy microorganisms
What is an antibiotic
A drug used to kill microorganisms in the body
What is a disinfectant
A substance used on non-living surfaces to destroy microorganisms
What affects the rate of bacterial growth
Temperature
Available nutrients
Oxygen levels
pH
How is the number of bacteria (end of growth) calculated
Number of bacteria (start of growth) * (2^number of divisions)
What is the zone of inhibition
The area where microorganisms have been killed or cannot grow
What did Ignaz Semmelweis do
Insisted doctors washed their hands before delivering babies
Helped to reduce the rate of death from childbed fever
What did Louis Pasteur do
Claimed that microorganisms cause disease
Developed vaccines from anthrax and rabies
What did Joseph Lister do
Encouraged the use of antiseptic chemicals so pathogens were destroyed before they could cause infection
What causes symptoms (in a viral infection)
Symptoms are the results of how the body reacts to the virus damaging cells as it reproduces
Why is it important to stop viruses from spreading
There are no medicines that cure viral disease
What are examples of viral diseases
Measles
HIV/AIDS
Tobacco mosaic virus
What are examples of bacterial diseases
Salmonella
Gonorrhoea
What is an example of a protist disease
Malaria
What is an example of a fungal disease
Rose blackspot
What do defence responses do
Keep out and destroy pathogens
What are examples of skin defences
Scabs
Antimicrobial secretions
Healthy microorganisms
What are examples of respiratory and digestive defences
Nose hairs and mucus
Trachea and bronchi cilia
Stomach acid
What do platelets do
Clot and seal cuts
What does mucus do
Traps particles
What do cilia do
Waft mucus to be swallowed
What does stomach acid do
Destroys pathogens
What do white blood cells do
Ingest microorganisms (phagocytosis)
Produce antibodies
Produce antitoxins
What are signs of plant diseases
Stunted growth Decay Growths Spots Malformations Visible pests Discolouration
How are plant diseases identified
By comparison
Expert opinion
Lab testing
Monoclonal antibody identification
How are plant diseases treated
Pesticide
Antifungal treatment
Removal
Deficiency rectification
What do aphids do
Penetrate phloem vessels
Deprive plants of photosynthesis products
Act as disease vectors
How are aphids treated
Chemical or biological pesticides
How do nitrogen deficiencies affect plants
Nitrogen ions convert sugars into proteins in photosynthesis
A deficiency results in stunted growth
How do magnesium deficiencies affect plants
Magnesium is needed to form chlorophyll
A deficiency results in yellowing (chlorosis) and reduced photosynthesis
What are examples of physical plant defences
Cellulose cell wall
Tough, waxy cuticle
Bark/layer of dead cells
Leaf fall
What are examples of chemical plant defences
Antibacterial chemicals
Poisons to deter herbivores
What are examples of mechanical plant defences
Thorns
Hairy stems/leaves
Drooping/curling
Mimicry
What are non-specific mechanisms
Defences that do not target a specific condition
Eg stomach acid, thorns
What are specific mechanisms
Defences that target a specific condition
Eg antibodies, antitoxins
How does leaf fall protect plants from diseases
Infected leaves are removed from the plant, preventing further infection
