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