Topic 5 Flashcards
How does the waxy cuticle help in defence against pathogens
It prevents entry of the pathogen
Benefits of garlic plants producing antiseptic chemicals?
Prevents damage to the plant
as the chemicals produced kill all the pathogens
Describe the stages of antibiotic development that would occur after the discovery of a new antibiotic
Pre-clinical trials - testing on animals (assess toxicity and starting dosage)
Clinical trials - testing on healthy volunteers (max and min dosage with no side affects)
Double blind trials (see the efficacy of the drug)
Children are vaccinated against tetanus. Explain why these children do not get tetanus if the bacteria enter their body through a cut in the skin
They are immune, the vaccination contained antigens of the bacteria, this means they have already produced memory lymphocytes which produce antibodies when in contact with the antigen, but will produce a secondary response which kills the bacteria quicker
Myxopyronin inhibits bacterial RNA polymerase. Explain why the antibiotic myxopyronin can be used to treat bacterial infections in humans.
antibiotics destroy bacteria
Myxopyronin prevents RNA polyermase binding and producing mRNA
this prevents transcription
and therefore prevents proteins being synthesised
Explain the effects of penicillin on bacterial and human cells - it inhibits the synthesis of the cell wall in bacteria?
Penicillin inhibits the bacterial cell producing a new cell wall, this stops it dividing and producing more,
Human cells do not have a cell wall and therefore are unaffected by penicillin
Explain how an adult develops immunity to the toxin produced by scarlets fever?
They may have been vaccinated which creates exposure to the antigen
this stimulates an immune response
with b-lymphocytes producing antibodies
and therefore the adult will have memory-lymphocytes
Describe how specific immune systems defend the body against diseases?
Pathogens have antigens
which triggers the production of antibodies
from the B-lymphocytes
the antibodies binding to the antigens leads to the destruction of the pathogen
and memory lymphocytes being produced
this then can lead to a secondary respone where the body can react and kill the bacteria quicker
Explain why monoclonal antibodies, used to detect blood group A, would not react with the blood of a person with blood group B?
Monoclonal antibodies shape is made to bind with a specific, complimentary antigen, Blood group A, blood group B would have a different shaped antigen and therefore the monoclonal antibodies would not bind to it
Explain how people become infected with both Chlamydia and Gonorrhoea
Both Chlamydia and Gonorrhoea are STIs and spread by bodily fluids, this means the individual is not using the barrier form of contraception
Explain why people with AIDS are more susceptible to TB.
They have fewer white blood cells which means they have less protection against pathogens entering the body and the body is unable to destroy the TB pathogens
In the body, fat tissue sends signals that cause other cells to divide.
Describe how this could cause cancer to develop.
Cells are triggered to divide by the fat, they divide by mitosis
This causes uncontrollable division
which causes the creation of a tumour
Describe how cancer develops in the liver?
Mutations in the DNA causes uncontrollable division of cells which leads to the formation of a tumour
Why can Chlamydia be treated with antibiotics
Because it is caused by bacteria which can be killed by antibiotics
What is MRSA
It is a bacterial infection resistant to antibiotics
