B5 Flashcards
define health
a state of physical and mental well-being
communicable disease
cashed by pathogens, can be spread form person to person
non-
communicable disease
not caused by pathogens, (genetic diseases, malnutrition) leading to deficiency diseases
correlation
a link between two factors that happened. not equal to cause
vaccine
harmless bacteria injected into the body, causing white blood cells to produce antibodies, creating immunity against the disease
droplet infection
transmitted through an ill person expelling droplets full of pathogens (coughing, sneezing, breathing, talking) being breathed in by people who are not ill, who pick up the infection. e.g flu, common cold, tuberculosis.
direct contact
spread by the direct contact of an infected organism with a healthy one. in plants; plant disease, where a tiny piece of infected plant material left in a field can infect an entire new crop. in people; STDs spread by direct contact of the skin. pathogens such as HIV/AIDs have to enter the blood through needle sharing/scratches
spread through water
in humans; eating raw, undercooked or contaminated food, drinking water containing sewage. the pathogens enter your body through your digestive system
antitoxins
substance made by white blood cells to counteract poisons produced by pathogens
antibiotics
medicines which kill bacteria
independent variable
the variable that is changed in an experiment
dependant variable
the variable that is measured in an experiment
control variable
the variable that is kept the same throughout an experiment
peer reviewing
vector
an agent that transmits infectious diseases
virus
live and reproduce inside the cells of your body, eventually damaging and destroying them
external defences
scabs, skin, ear wax, nose hair (eye lashes, ear hair), tears
internal defences
cilia, white blood cells, mucus, stomach acid
white blood cell products
ingesting microorganisms; destroying them so they don’t make you ill. producing antibodies; each pathogen requires a unique antibody. producing antitoxins; cancelling out the toxins released by pathogens
non specific defences
first line of defence; hairs, mucus, skin, stomach acid, cilia, scabs
symptoms of gonorrhoea
thick yellow discharge, abdominal pains
why will antibiotics not cure HIV?
HIV is a virus. antibiotics are only effective against bacteria
why are tools washed in disinfectant after use on plants with TMV
to kill the virus and prevent it spreading
why do plants with TMV have stunted growth
less photosynthesis sue to lack of chlorophyll
less glucose made
less energy released for growth, because glucose is used for respiration