Infection And Response 💘 Flashcards
What is a pathogen?
Any microorganism that causes disease
State the four main groups of pathogens and give an example of each
Bacteria e.g. Food poisoning
Virus e.g. Cold
Fungus eg athletes foot
Protist eg malaria
Describe the pathogens ‘ differences
A virus is not living
Bacteria produces toxins protist is carried by a vector
Explain how the spread of a disease can be reduced or prevented
Jabs vaccines and good hygiene by washing your hand regularly
Describe symptoms and effects of two different plant diseases
Rose black spot:black splotched on surface of leaves
Tobacco mosaic: yellowing and curling of leaves
What are the two ion deficiencies we have learnt and what effect do they have on plants?
Lack of nitrates causes stunted growth
Lack of magnesium causes chlorosis
List the main safety conditions when culturing microorganisms
Use a sterilised item to put the bacteria on the petting dish so the results are accurate
Put the Petri dish in the right temperature (25orbelow)if at 37 could cause a human pathogen
Sellotape the lid
Don’t open or have food around
Describe how you could recognise bacterial or fungal growth on a Petri dish
Smooth dots for bacteria yellowy brown colour
Furry dots or shapes for fungi could have roots coming out of it
What conditions do microorganisms need to grow
Warm moist place where there are nutrients
What is athletes foot and symptoms
It’s a rash caused by a fungus that usually appears between the toes
Affected area is red dry and flaky
Describe the life cycle of malaria
Mosquito bites infected human and picks up plasmodium which undergoes several stages of development in mosquito it then bites another human injecting plasmodium sporozoites which affect liver cells which when affected burst releasing plasmodium that infects red blood cells which then burst infecting and Mosquitos that bite the human
What are bodies first line of defences?
Skin,mucus,cilia,tears,stomach acid etc
Explain how the immune system defends against disease
The lymphocytes recognise and remember how to treat the disease as it has already treated before
Describe all the jobs of white blood cells.include phagocytosis antitoxin and antibodies in your response
There are two types of white blood cells lymphocytes make antitoxins antibodies and memory cells
Phagocytes engulf and ingest the pathogen so when your body gets that disease again it will know how to treat it
What is a vaccine
Dead weakened version of an antigen from a pathogen or microorganism in a form of a medicine
This triggers a low level immune response so your body can respond more quickly to the pathogen if infected later
How do vaccines prevent disease don’t forget to refer to next time in your answer
Because vaccines have the weakened version of the disease it won’t affect a human that much The vaccine is so the lymphocytes can learn to make antibodies for it and the phagocytes can ingest it so the next time you get that disease your white blood cells recognise ur and know how to get rid of it faster making you immune to the disease
Explain herd immunity
If there are people around you that have had a vaccine for a certain disease you still won’t get the disease because people are immune to it and can get rid of the disease so no one can pass on the disease to you
What can patients and doctors do to prevent antibiotic resistant bacteria forming
Doctors can prescribe antibiotics correctly
Patients can take the full prescribed course even if you feel better before it
What process causes bacteria to become resistant to antibiotics
Natural selection or gene mutations occur before the antibiotic is in the body bacteria without the mutation die and the others don’t
Why is a problem developing drugs that kill viruses
To reproduce viruses insert themselves into living cells so if you tried killing a virus you would be damaging your own cells which is dangerous
How would you calculate the cross sectional area in a Petri dish that has been killed by an antibiotic dish
Find the are of the circle pi x radius squared
Who discovered penicillin and how did he make his discovery
Alexander Fleming discovered penicillin by noticing that a mould with a bacteria free circle had formed on his Petri dish while studying penicillin
Describe the entire process of developing a new drug
what types of things are being tested at each stage
Include placebo double blind trial clinical toxicity efficacy and preclinical
First you do a preclinical test which is testing the drug on human cells in a lab next is the clinical test where you test it on healthy humans to test the toxicity efficacy and dose finally the drug is tested on patients sometimes control groups are given a placebo which is a no medication pill
What are monoclonal antibodies
They are antibodies that target a certain cell or chemical in or outside the body and are made in labs
What are mabs made of
Made of b lymphocytes from mice and tumour cells which then produces a hybridoma cell which can divide and make antibodies which are then cloned purified and ready to use
How do monoclonal antibodies relate to antigens
They bind to a specific cell the antibody covers the cells antigen therefore restricting the cell form getting protein which causes the cell to die
How are monoclonal antibodies used in pregnancy tests
Monoclonal antibodies bind to a hormone called hcg which is made in the early stages of pregnancy and is passed out of the body in urine
What is the independent and dependent variable
Dependent variable is the value observed by the researcher during the experiment
The independent variable influence change in the dependent variable
What are control variables
Variables that are not changed to make sure it’s a fair test
How is a control and a control variable different
A control is a second set is data which is bit affected by the substance being measured this is so you can compare the results this is different to a control variable because you are not changing the variable
What’s an interval
How much you go up on in an independent variable
How can data be more reliable
Do more repeats
Describe the effect on death rate of having only nurses working in Ward B and not doctors doctors didn’t wash hands
Lower percentage of women died
Other than improvements in hygiene, give two reasons for the low death rate from infectious diseases in modern hospitals.
Vaccines
Better knowledge on immunity
Infectious
Describes a pathogen that can easily be transmitted or an infected person who can pass on a disease
Vector
An animal that spreads a communicable disease e.g. Mosquitos for malaria
