B5 - communicable diseases exam questions Flashcards
viruses cause disease
what name is given to microorganisms which cause infectious disease (1 mark)
pathogen
how do viruses cause symptoms of disease (1 mark)
viruses reproduce inside cells, damaging them
suggest one reason why viruses are not considered cells (1 mark)
- they do not have a cell membrane
- they do not have a cytoplasm
- they do not have a nucleus
- they do not have mitochondria
- they do not have ribosomes
what does a vaccine contain (1 mark)
a weakened form of a virus
which part of a plant shows discolouration caused by TMV (1 mark)
leaf
name one type of pathogen that causes infectious disease (1 mark)
bacteria, fungi, protists
which 2 defence systems prevent microorganisms infecting the human body? (2 marks)
air is warmed as it is breathed into lungs
hydrochloric acid is produced by the stomach
teeth in the mouth crush and kill microorganisms
the skin is a barrier covering the whole body
hydrochloric acid is produced by the stomach
the skin is a barrier covering the whole body
how does the immune system destroy microorganisms? (1 mark)
white blood cells engulf the microorganisms
complete the sentences (2 marks)
In a vaccine, the measles virus is ____________.
If the measles virus enters the body after vaccination the immune system reaction will be ________________.
IN THIS ORDER ONLY
weakened
fast
how is the measles virus spread from one person to another? (1 mark)
by coughs and sneezes
how do poisonous berries help a deadly nightshade plant survive (1 mark)
prevent animals from eating them/it will not be eaten
what type of defence mechanism are berries on a deadly nightshade plant (1 mark)
- chemical
- mechanical
- physical
chemical
what factors must a drug be tested for in trial? (3 marks)
toxicity, efficacy and dosage
what type of pathogen causes malaria (1 mark)
a protist
describe how the human body:
- prevents pathogens from entering the body
- defends itself against pathogens inside the body
(6 marks)
prevents pathogens from entering body:
- skin acts as a barrier
- scabs form a barrier over cuts
- platelets form clots/scabs
- stomach contains hydrochloric acid to kill bacteria ingested
- eyes produce tears which contain enzymes to kill bacteria
- mucus is sticky and traps bacteria
defends itself from pathogens inside the body:
- white blood cells engulf pathogens
- antibodies destroy pathogens
- antitoxins neutralise toxins
- memory cells cause a more rapid response when pathogen re-enters the body
a man has the following symptoms:
- yellow discharge from his penis
- pain when urinating
the man has a bacterial infection. what is most likely the cause of the man’s symptoms?
why did the antibiotics not cure his symptoms?
using a condom can help stop the bacteria from being passed on to another person during sexual intercourse. name one other way the could avoid passing bacteria on
(3 marks)
gonorrhoea
the bacteria was resistant to the antibiotics
abstain from sexual intercourse
two symptoms of infection by salmonella are vomiting and diarrhoea. what causes these symptoms? (1 mark)
bacteria release toxins which make us feel ill
where were these drugs originally extracted from? (2 marks)
digitalis
aspirin
IN THIS ORDER ONLY
foxglove
willow tree
why do some patients take a placebo (1 mark)
acts as a control
explain why prescribing an antibiotic will not cure HIV (2 marks)
HIV is a virus and antibiotics do not kill viruses (viruses live inside of cells)
