biology b6 Flashcards
(59 cards)
what is a disease?
a condition that is caused by any part of the body not functioning properly
what can diseases affect?
mental and physical health
what is a communicable disease?
diseases that can be spread between organisms
what is a non communicable disease?
diseases cannot be spread between organisms
what can cause communicable diseases?
most are caused by microorganisms (parasites)
when they enter the organism (pathogen)
what are causes of non communicable diseases?
poor diet
obesity/lack of exercise
genetic disorder
body processes not operating correctly
what does HIV do?
weakens a persons immune system
what does HPV cause?
cervical cancer
how are pathogens spread between animals?
through cuts in skin
digestive system (when foods/drinks are shared)
respiratory system (inhaling pathogens)
reproductive system (sexual intercourse)
how can pathogens spread between plants?
vectors (insects)
direct contact of sap from an infected plant
wind (blown between plants)
how do pathogens cause diseases?
incubation period-
pathogens reproduce rapidly and as they grow, they cause cell damage and produces toxic waste products
how do viruses reproduce / ‘take over’ cells?
- virus attacks cell
- inserts it’s genes
- ‘tells’ nucleus to copy its genes
- new viruses are made
- cell bursts, releasing the new viruses, destroying more cells
what is the difference between vector and pathogen?
pathogen causes a disease
vectors spread the disease
what are the two types of white blood cells called?
lymphocytes
phagocytes
what do phagocytes do?
engulf the microorganisms then make enzymes that digest the microorganism
what do lymphocytes do?
make antitoxins or antibodies
what is a vaccination?
a dead/weakened pathogen that is inserted into the bloodstream.
Explain how vaccines work
- small amount of dead/weakened pathogen inserted into your body by injection
- antigens in the vaccine stimulate WBCs to make antibodies
- the antibodies destroy the antigens
- memory cells are then produced to prevent infections by responding quickly
how are pathogens killed?
antiseptics
antivirals
antibiotics
what do antiseptics do?
kill / neutralise all types of pathogens but do not damage human tissue. e.g iodine , alcohol
what do antivirals do?
drugs that destroy viruses by preventing them from replicating, treat infections
what does the antiviral drug do?
- blocking the virus from entering host cell
- prevents virus from releasing genetic material
- prevents virus from inserting its genetic data into host cells dna
what do antibiotics do?
drugs that kill bacteria without damaging cells
how do you identify the bacteria and which antibiotic to use?
doctors send blood / stool samples to a laboratory
scientists grow the bacteria on agar plates
they are treated with different antibiotics
the antibiotic that is the most effective is used on patient