diseases - Biology Flashcards
what is a pathogen?
a harmful microorganism that invades a person’s body causing illness
what are the types of communicable diseases?
virus, bacterium, fungus or protist
give some examples of viruses
Measles, HIV, Tobacco mosaic virus
give some examples of bacterium
Salmonella, gonorrhoea
give examples of fungi
rose black spot
give examples of protists
malaria
what is the difference between communicable and non-communicable diseases?
communicable diseases spread through organisms, whereas non-communicable diseases do not spread between organisms and instead are transmitted through genetic, environmental, or lifestyle factors
how does bacteria harm the body?
reproduces rapidly and produces toxins that damages tissues and causes illness
how do viruses harm the body?
live and reproduce inside cells, leaving to damage or potentially destroy them
what are some signs of diseases in plants?
stunted growth, spots on leaves, areas of rot or decay, malformed stems or leaves, discolouration, pest infection
what are the three types of plant defences against diseases?
physical barriers, mechanical adaptations, chemical barriers
what are some physical barriers of plants?
cellulose cell walls, waxy cuticle, bark on trees - layer of dead cells that can fall off
what are some chemical barriers of a plant?
many plants produce antibacterial chemicals
what are some mechanical adaptations of a plant?
thorns and hairs to stop animals from eating them, leaves that droop or curl to scare off herbivores or dislodge insects, mimicking the appearance of unhealthy or poisonous plants
how do aphids infect diseases to plants?
they insert their mouth piece into the plant to suck out sap
what effects do aphids leave to plants?
reduced rate of growth, wilting, discolouration
what is a vector?
an organism that transports pathogens from one host to another
give examples of vectors
mosquitos, ticks
in what ways can we prevent the spread of communicable diseases and explain each one
- hygiene - keeping infection limited through contact by destroying bacteria
- isolation - keeping an infected person away from other people
- controlling vectors - destroying vectors such as mosquitos which carry malaria
- vaccination - injecting a harmless virus that the white blood cells produce antibodies against
in what 3 ways to pathogens spread?
- in the air
- direct contact
- in water
what are some external defences of the human body?
- skin
- mucus
- stomach acid
what ways do white blood cells destroy and protect you from pathogens?
- ingesting the pathogen
- producing antibodies against the antigens
- producing antitoxins to counteract the toxins produced by the pathogens
what is herd mentality?
when a collective group of people are immune to a disease, and therefore cause the number of cases to rapidly decrease
what are antiseptics?
chemical agents that destroy or prevent the growth of bacteria on the tissues of living organisms
what are disinfectants?
chemical agents that prevent the growth of harmful bacteria on non-living objects
what are the disadvantages of using antibiotics?
- antibiotics don’t work on viral pathogens
- a bacteria can become resistant to that antibiotic assigned to it
what 3 areas of effects are new drugs tested for?
- efficacy
- toxicity
- dosage
what are the stages of developing a drug?
- drug discovery
- preclinical trials
- clinical trials 1 (low dosage to small number of healthy people)
- clinical trials 2 (given to small number of patients with the disease)
- clinical trials 3 (given to larger amount of patients to find the optimum dosage)
what are malignant Tumors?
Tumors which can break off into the bloodstream, causing them to infect many other areas of the body
what are benign Tumors?
Tumors which do not spread to other parts of the body
what are carcinogens?
substances that can cause cancer
what are some life-style factors of cancer?
smoking, exposure to UV rays, obesity, common viruses
