B5 - communicable diseases fact test Flashcards
what is the definition for health
health is the state of physical and mental wellbeing
what are communicable diseases
disease that can be spread from person to person and caused by pathogens
what are non-communicable diseases
diseases that are not caused by pathogens and cannot be spread
what are pathogens
pathogens are microorganisms that cause infectious disease in plants or animals, and include bacteria, viruses, fungi and protists
how do bacteria make you feel ill
produce toxins that damage cells
how do viruses make you feel ill
reproduce inside cells which damages them
how can pathogens be spread
water, air or direct contact
how can the spread of disease be prevented
- being hygienic
- destroying vectors
- isolating infectious people
- using vaccinations
name everything you need to know about measles
- viral disease
- symptoms include fever and red skin rash
- spread by inhalation of sneeze and cough droplets
- it’s a serious illness and can be fatal in complications arise so most young people are vaccinated
- to prevent the spread, young people are vaccinated
name everything you need to know about HIV
- viral disease
- symptoms are a flu-like illness
- spread by sexual contact or exchange of bodily fluids e.g. sharing needles
- if it’s not controlled by antiretroviral drugs, the virus attacks the body’s immune cells
- later stage HIV leads to AIDS which occurs when the body’s immune system becomes so badly damaged it can no longer deal with other infections
- to prevent the spread don’t share needles, use barrier methods of contraception or abstain from sex
name everything you need to know about TMV
- tobacco mosaic virus is a viral disease
- symptoms include mosaic pattern of discolouration on the leaves which affects the growth of the plant due to a lack of photosynthesis
- spread by direct contact or vectors
to prevent the spread, cut off diseased leaves or burn the infected leaves
name everything you need to know about salmonella
- bacterial disease
- symptoms include fever, abdominal cramps, vomiting and diarrhoea
- spread by bacteria ingested in food or on food prepared in unhygienic conditions
- in the UK, poultry are vaccinated against salmonella to control the spread
- to prevent the spread, avoid cross contamination, thoroughly cook meat, poultry and eggs
- wash hands after touching raw meat and using the bathroom
name everything you need to know about gonorrhoea
- bacterial disease cured by antibiotics
- symptoms include thick yellow or green discharge and pain when urinating
- spread by sexual contact
- to prevent the spread, use barrier methods of contraception or abstain from having sex
name everything you need to know about rose black spot
- fungal disease
- symptoms include purple or black spots on leaves, leaves drop early, stunted growth as photosynthesis is reduced
- spread by water or wind
- treated using fungicides
- to prevent the spread, remove/destroy affected leaves
name everything you need to know about malaria
- caused by protists
- symptoms include recurrent episodes of fever
- spread by mosquitoes carrying malaria (a vector)
- to prevent, prevent mosquitoes from breeding, use mosquito nets to avoid being bitten
name some human defence systems and how they act as a defence
- skin acts as a physical barrier
- hair
- tears have antibacterial enzymes and antibodies
- platelets in blood stop infection from entering through a cut
- phlegm contains mucus
- eyelashes and eye lids
- hairs and wax in ears
- mucus and hair in nose to stop pathogens entering
- stomach acids contain hydrochloric acid that destroys ingested microorganisms
what do white blood cells do
- help defend the body against pathogens by:
- phagocytosis - white blood cells engulf pathogens
- antibody production - white blood cells have receptors which attach onto the antigens (proteins) on the pathogens
- antitoxin production - white blood cells neutralise the toxins produced by bacteria
how do bacteria divide
binary fission
how often do bacteria divide
as often as once every 20 minutes
what conditions are needed for bacteria to divide
enough nutrients and a suitable temperature
how do you work out the number of bacteria present after a certain number of divisions
original number x 2^number of divisions
why are magnesium ions needed in plants
to make chlorophyll
therefore a lack of magnesium results in chlorosis
why are nitrate ions needed in plants
needed for photosynthesis and therefore growth so a deficiency in nitrates causes stunted growth
what are common symptoms of plant disease
- stunted growth
- spots on leaves
- patches of decay
- abnormal growth
- malformed stems/leaves
- discolouration
- the presence of pests
