B6 Flashcards
what is genetic engineering?
moving genes for desirable characteristics from one organism to another
what is a vector used for?
inserting DNA into another organism
what are antibiotic resistance markers used for?
selecting cells with the new DNA
what is a healthy organism?
an organism having complete physical and mental well-being
what is a disease?
a condition that impairs the normal functioning of an organism
what are three causes of diseases?
-pathogens
-mutations in genes
-environmental conditions- poor diet, lack of exercise
what is a pathogen?
a type of microorganism that causes disease
what are the four types of pathogen?
-fungi
-protists
-bacteria
-viruses
what is a communicable disease?
a disease that can spread between organisms- that you can catch and is caused by a pathogen
what is a non-communicable disease?
diseases that develop and cannot be passed from person to person
what is bacteria?
very small cells which reproduce rapidly and make you feel ill by producing toxins that damage your cells and tissues
what is a virus?
not a cell, but replicates inside the affected organisms cells and the cells burst and release viruses
what are protists?
eukaryotic, single celled organisms that cause disease
what is fungi?
single celled cell and has thread like structures (hyphae) which can grow and penetrate human skin and surface of plants which causes disease.
how do pathogens spread in water?
pathogens can be picked up by drinking dirty water.
how do pathogens spread in the air?
they are carried by the air and people can breath them in
how do pathogens spread through contact?
pathogens can be picked up by touching contaminated surfaces
how do pathogens spread through body fluids?
pathogens can be spread through body fluids e.g blood by sharing needles, through sex, or breast feeding
how do pathogens spread through animal vectors?
animal that spread diseases are called vectors as they carry them. e.g malaria is caused by the animal vector mosquito which carries the pathogen
how do pathogens spread through soil?
pathogens can live in soil so plants in the contaminated soil may be infected
how do pathogens spread through food?
some pathogens can be picked up by eating contaminated food
how are communicable diseases affected by social and economic factors?
-crowded areas means communicable diseases are transferred more easily
-poor diet increases the risk of infection because the immune system is weak and there is not enough nutrients
-limited access to healthcare and health education means people are not educated or treated
what are four ways that the spread of disease can be reduced in humans?
-being hygenic
-destroying vectors which carry pathogens and spread disease- can be killed using insecticides or by destroying their habitat
-isolating infected individuals
-vaccination which means they wont develop the infection and pass it on
what are five ways that the spread of disease can be reduced in plants?
- making sure the infected plant doesn’t come in contact with a healthy plant
-destroying infected plants
-changing crop rotation- stops pathogens being established in that area
-chemical control- killing or preventing pathogens
-biological control- dipping roots into similar bacterium before they are planted in infected soils- produces an anitbiotic
how does your body fight against pathogens?
-skin: acts as a barrier to pathogens
-skin secretes antimicrobal substances which kill pathogens
-nasal passage, trachea and lungs lined with mucus and cilia- hairs trap particles that might have pathogens in them and cilia waft mucus up to the back of the throat where it can be swallowed
-eyes produce an enzyme called lysozyme which breaks down bacteria in the eye
-stomach produces hydochloric acid to kill pathogens
-platelets clump together to create a scab- blood clotthing- which prevents you from losing blood and a microorganism entering the wound
how does your immune system fight off pathogens?
-white blood cells (phagocytes) consume pathogens. they have a flexible membrane and contain lots of enzymes to do this
-white blood cells produce antibodies which lock onto invading cells. antibodies are specific to the type of antigen. antibodies help phagocytes find the pathogen so they can engulf them
-white blood cells produce antitoxins
what are memory cells?
cells that remember the shape of a certain pathogen which allows antibodies to be produced and destroy the pathogen
what does a vaccination do?
you inject a dead, inactive or weakened pathogen into the body. they carry antingens and your white blood cells produce antibodies to attack them. when you actually become infected, the antigens will remember the shape of the pathogen and antibodies will help destroy the pathogens
what are antibiotics?
chemicals that kill bacteria without killing your own body cells. many are produced naturally by fungi or other microbes.
what are antivirals used to treat?
viral infections.
however they are difficult to produce because viruses use host cells to replicate- it’s hard to target the virus without damaging the cell . most antivirals don’t kill the virus but stop them from reproducing.
what are antiseptics?
chemicals that destroy micro-organisms or stop them growing. they are used on the outside of the body to clean wounds and surfaces. used to prevent infection rather than treat it.
where are antiseptics often used?
in hospitals and surgeries to prevent the spread of infection
what are 3 aspetic techniques to make sure culture doesn’t get contaminated?
-regularly disinfect work surfaces
-sterilise equipment before and after use
-work near a bunsen burner flame which will draw away microbes
why do new drugs need to be tested?
to make sure they are safe and work and make sure they have no harmful side effects.
how are drugs developed and tested?
- computer models are used to stimulate a human response to the drug. it’s not as accurate as seeing the effect on a live organism.
- drugs are tested on human tissues. However, you can’t use tissue to test the overall effect on the body from the drug.
- test the drug on animals.
why are drugs tested on healthy volunteers?
sick people are more vunerable to damage a drug could do
what are the two groups of patients in clinical trials?
group 1 is given the new drug
group 2 is given a placebo ( a substance that looks like the drug but doesn’t do anything)
what is the placebo effect?
when a patient is given a substance that looks like a drug but doesn’t do anything- the patient expects for the treatment to work and so feels better even though the treatment isn’t doing anything)
it lets the scientists see if the drug actually works
how does exercise prevent the risk of non-communicable diseases?
exercises increases the amount of energy used by the body and decreases the amount of stored body fat, which boosts metabolic rate.
how does diet increase the risk of non communicable diseases?
too much fat in your diet can increase blood cholesterol levels which can cause fatty deposits to form inside the arteries which can lead to coronary heart disease.
how does smoking increase the risk of non communicable diseases?
-you can get CVD as carbon monoxide reduces the amount of oxygen being carried in the blood. if the cardiac muscles don’t receive enough oxygen it can cause a heart attack.
-you can get lung, throat, mouth and Oesophageal cancer from the tar in cigarettes
-cigarette smoke can cause inflammation of the bronchi which can cause lung diseases.
how does alcohol increase the risk of non communicable diseases?
when alcohol is broken down by enzymes the products are often toxins.
alcohol increases blood pressure which can lead to CVD
what does cardiovascular disease affect?
the heart and blood vessels