Infection And Responss Flashcards
What do antiretroviral drugs do?
They stop the virus replicating in the body
How do viruses spread around the body
They use the cell’s biochemistry (protein synthesis) to replicate themselves
Eventually the cell bursts and the viruses spread around the body
How does TMV spread, how is it prevented?
(TMV Reduces ability to photosynthesise by infecting chloroplasts, reducing yield)
Direct contact.
Growing resistant strains and removing infected leaves.
What does HIV do to the body and how is it controlled
After months of being inactive, it begins to attack the immune system, and when this has done enough damage it becomes AIDS.
This means the individual is more susceptible to other pathogens.
Its controlled using antiretroviral drugs, condoms, and screening blood used for transfusions.
What causes rose black spot and how does it spread
How is it prevented and what does it do
Fungi. Wind or water.
Remove and destroy infected leaves and fungicides
Causes leaves to turn yellow and drop off. Less photosynthesis so can’t grow well.
How is malaria spread
What does it do
How is it prevented
When a mosquito (vector for malarial protist) feeds on an infected animal
It infects the next animal it feeds on by inserting parasite into its blood vessels
They parasites enter red blood cells. When they burst It causes repeating fevers and can be fatal.
Prevent with mosquito nets and insecticides, stopping mosquitos from breeding by removing stagnant water.
Antimalarial drugs
Explain how the immune system detect foreign bodies and gets rid of them
How does this lead to immunity?
Lymphocytes detect foreign antigens on the pathogen
Lymphocytes releas specific antibodies for that antigen
Antibodies bind to the antigens, preventing the pathogen from damaging cells and causing them to clump together. Stimulates phagocytes.
Phagocytes engulf the clump and destroy the pathogens with enzymes
The lympochytes remain in the bloodstream, and if the infection occurs again, they’re rapidly produced and the pathogens are killed so no symptoms occur. These are called memory cells.
What are the stages in the development of a new drug (testing)
First its tested on human tissues to see the effect it has on cells, and animals (effects may be different to humans)
Then on healthy volunteers in low dosage to test for side effects
Then on patients to find the optimal dose (most effective while minimising side effects)
Then blind trials to test the efficacy - some placebo some real.
Not published until peer review to prevent false claims
How can monoclonal antibodies be used to treat cancer?
Monoclonal Antibodies that bind to cancer cell antigens can be made.
Radioactive drugs/ chemicals to kill the cell
Or chemicals to prevent it from growing (without damaging other body cells) by blocking receptors that detect growth stimulating molecules
How can monoclonal antibodies be used to locate things in the body
The antibody can be produced to bind to a specific antigen (such as a hormone, pathogen)
Such as in blood donations / patients for HIV pathogen
By attaching a fluorescent dye to the antibody, which can be used to detect the substance when it has binded
Issues with monoclonal antibodies?
Although they target specific cells/ molecules, they can cause side effects like fevers and vomiting
How are monoclonal antibodies made
A mouse is injected with the pathogen
Stimulate mouse lymphocytes to produce the antibody for the pathogen
B-Lymphocytes are extracted and combined with a tumour cell
To create a hybridoma, which rapidly divides to produce many clones
All the clones produce identical monoclonal antibodies for a specific antigen.
The antibodies are extracted and purified.
Why do plants need magnesium and nitrates and what effect does a lack of them have
Magnesium is used for making chlorophyll (absorbs sunlight) which is used in photosynthesis. Lack = chlorosis (discolouration)
Nitrates are needed for making proteins (combined with glucose) and so for growth.
Lack of them means stunted growth / death.
Plant defences against:
Micro-organisms (physically, chemically)
Animals (physicslly, chemically)
M.O:
(Physical) Strong cellulose cell walls
Dead cells around stem such as bark
(These both prevent infection/access)
Waxy cuticle on upper epidermis of leaves
(Chemical - bacteria)
Antibacterial chemicals
(Physical - animals)
Thorns and hairs to deter animals
Patterns that look like eggs so animals dont lay their own (competition)
(Chemical - animals) Poisons to deter herbivores
(Must include in answers to relevant questions) why do mAbs bind to the antigen
Their shape is specific to the antigen they’re made for
