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18 Cards in this Set
- Front
- Back
What is tobacco mosaic virus? |
It is a plant disease that causes the leaves to discolor in a mosaic pattern. Because of the discolouration, the rate of photosynthesis is reduced. The means the growth of the plant is also reduced. |
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What is rose black spot? |
It is a plant disease caused by a fungus. It causes the leaves to develop purple or black spots. The leaves can then turn yellow and drop off. It causes the rate of photosynthesis to decline and this reduces the rate of growth. |
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Name six features a diseased plant may have. |
Discolouration Spots on leaves Stunted growth Decay/rot Growths Malformed stems or leaves |
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Physical plant responses? |
Cellulose cell wall - difficult to penetrate Leaves are covered with waxy cuticle - again difficult to penetrate Bark is a barrier |
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Chemical plant responses? |
Plants can release antibacterial chemicals which kill bacteria They can release poisons to deter herbivores. |
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Mechanical plant responses? |
Sharp thorns Hairs which irritate the mouth of a herbivore Leaves which droop or curl when touched to deter herbivores Mimicry - white dead nettle looks like stinging nettle |
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What is phagocytosis? |
The white blood cell detect chemicals released from the pathogen and moves towards it. The white blood cell then ingests the pathogen. Now the white blood cell uses enzymes to destroy the pathogen. |
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What do antibodies do? |
They are produced by white blood cells to destroy the pathogen. Specific antibodies can stick to specific antigens so they can be found and destroyed by other white blood cells. |
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What is vaccination? |
It involves injecting small amounts of dead or inactive pathogens. These carry antigens, which cause your body to produce antibodies to attack them. If pathogens of the same type infect you, the white blood cells can mass produce antibodies. |
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Describe the process of monoclonal antibodies. |
A mouse is injected with the chosen antigen. A B lymphocyte cell is taken from the mouse and fused with a tumour cell. This is a hybridoma. This divides quickly to produce lots of clones that produce the monoclonal antibodies. |
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Describe the use of antibodies in a pregnancy test. |
A hormone called HCG is only found in the urine of pregnant women. The part where you wee has antibodies to the hormone, with blue beads attached. The test strip has more antibodies attached. If you're pregnant, the hormone binds to the antibodies on the blue beads. The urine moves up the stick, carrying the hormone and the beads. The beads and the hormone bind to the antibodies on the strip turning the strip blue. If you're not pregnant, there's nothing to stick the blue beads onto the test strip. |
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What are new drugs tested for? |
Efficacy - how well the drug treats the illness Toxicity - does the drug have any unwanted side effects Dose - how much of the drug has to be given |
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What are the two main stages of drug testing? |
Pre clinical testing - the drug is tested on cultured cells, tissues and live animals. Clinical trials - the drug is tested on healthy volunteers and patients. This is only done if the drug had passed pre clinical trials. |
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Who is the drug tested on in the clinical trials? |
Firstly, healthy volunteers to check for safety Then volunteer patients to see if the drug is effective. |
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What is measles? |
It is a virus, and the first symptom is often a fever. Around three days in, the patient develops a red skin rash. It is spread in droplets |
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What is HIV? |
It is a virus that attacks the cells of a patients immune system. Over time, it becomes severely damaged. When it is so badly damaged and cannot fight off infections it is AIDS. You can treat it with antivirals to stop it from multiplying inside your cells. |
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What is salmonella? |
A bacteria that causes food poisoning. It is spread by eating infected food. |
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What is malaria? |
It is a protist. To infect someone, a mosquito bites an infected person. The mosquito then bites an uninfected person and passes the pathogen on. |