Extra questions B6 Flashcards
There has been a large increase in the populations of many antibiotic- resistant strains of bacteria in recent years. explain why.
- non-resistant strains killed (by antibiotics)
- so less competition
- overuse of antibiotics
Explain how vaccination makes a person immune to a disease
- dead or inactive or weak form of pathogen injected
- stimulates whit blood cells
- produce antibodies
- antibodies made quickly when reinfected as memory cells remeber which antibody kills specific pathogen.
Explain, in terms of natural selection, why the number of people infected with the resistant strain of the bacterium is increasing.
- antibiotics kill non-resistant strain
- resistant strain bacteria reproduce
- proportion of resistant bacteria increases
Suggest a reason for the amount of deaths decreasing of infections by antibiotic resistant bacteria
- more use of hand washing
- reduces the bacteria being transferred
Before 2007 there was a rapid increase in the number of deaths caused by MRSA.
Describe how the overuse of the antibiotic methicillin led to this increase.
mutation occurred giving resistance
resistant bacteria not killed
these bacteria reproduced
Where do mutations happen in a bacterial cell?
plasmids
Stem cells containing antibiotic were produced by growing the cells for 24 hours in a solution containing the antibiotic. How did the antibiotic enter the stem cells from the solution? Give a reason
Diffusion
Concentration of antibiotic lower inside cells than in solution.
The number of deaths from EVD continued to increase.
The World Health Organization (WHO) decided it was ethical to use unlicensed drugs.
The WHO said unlicensed drugs could only be given to people who gave their permission.
Also, any results had to be shared with other researchers and drug companies.
Some vaccines had shown positive results in animal testing, but the vaccines had not been tested and trialled in humans.
The supplies of the vaccine were low.
At first the vaccines were only used for health workers.
Evaluate the use of unlicensed drugs and vaccines during the EVD outbreak.
Pros:
* might save some lives
* vaccine could reduce chance of future outbreaks
* patient made aware of risk and agreed to use of drug
Cons:
* could be dangerous
* goes against legislation
Suggest why we take aspirin for pain relief rather than willow bark
- other compounds in willow bark may result in unwanted side effects
- amount of aspirin in willow bark is unknown
- you may take too much and cause health issues
- amount of aspirin in aspirin tablet is controlled
Explain how natural selection could have produced strains of penicillin resistant bacteria (5)
- mutation gives resistance to penicillin
- some survive penicillin
- survivors reproduce
- through asexual reproduction
- gene for resistance is passed on to offspring
Why would a person immune to a disease have a rash on their skin when given the vaccine
Antibodies in blood react with injected antigens
Suggest the possible cause of the reaction when a person who is already immune is
tested
already have the antibodies
react
with (injected) antigens
Occasionally a new, resistant strain of a pathogen appears. The new strain may spread rapidly. Explain why
antibiotics ineffective resistant pathogens survive.
produce, and increase
Antibiotic-resistant strains of bacteria are causing problems in most hospitals. Explain, as fully as you can, why there has been a large increase in the number of antibiotic-resistant strains of bacteria
- overuse of antibiotics
- bacteria mutate
- antibiotics kill non-resistant strains
- reduced competition
- resistant bacteria reproduce
Why are children in the UK still vaccinated for polio
Disease could be reintroduced from abroad
