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
how are blood clots caused?
when bits of atheromas break off or damage the blood vessel which causes a blood clot. this can lead to a heart attack
what does CVD stand for?
cardiovascular disease
how is stent surgery done to treat CVD?
stents are inserted into arteries and they keep them open to make sure blood can pass through to the cardiac muscle.
however, overtime the artery can narrow again and stents can irritate the artery and make scar tissue grow. the patient has to take drugs to stop blood clotting on the stent
what is a stent?
a tube inserted into the artery
what surgery can be done to help CVD if an artery is blocked?
conorary bypass surgery: a piece of healthy vessel from somewhere else in the body can be used to bypass the blocked section.
how can donor hearts be used to treat CVD?
can be used to all together replace the heart
however, the new heart does not always start pumping properly and the new heart may be rejected. Drugs can be taken to prevent this but they have side effects and make you more vunerable to infection.
what is an example of using adult stem cells to treat cancer?
luekemia a cancer of the blood or bone marrow has been treated through bone marrow transplants. Bone marrow contains stem cells in the transplanted bone marrow to produce healthy blood cells.
what are the concerns of transplanting tissues or organs from stem cells?
it may lead to rejection because the patients immune system recognises them as foreign and attacks them
why are some people against stem cell research?
they feel that human embryos have a potential human life .
what was the human genome project?
a 13 year long project which identified all the genes found in the human DNA.
what are the three benefits of genome research?
-we can prevent and predict diseases and what causes them
-develop new and better medicines
-highlight common genetic variations between people and some variations make drugs less effective.
what are 3 risks with gene technology?
-increased stress- if someone knows they will have a certain disease
-gene-ism- people with genetic problems might come under pressure not to have children
-practical risks- we don’t know what effects there may be in future generations
what is the different between climate and weather?
weather is short term atmospheric conditions
climate is typical weather conditions in a region for a long time
what does GMO stand for?
genetically modified organism
what is a gene pool?
all the genes and their alleles in a population
what is the disease that HIV develops into?
AIDS
what is domestication?
when animals or plants are selectively breed to be more tame and more useful to us
what is genetic engineering?
modifying an organism’s genome to give it a desired characteristic.
what do restriction enzymes only cut at?
specific base sequences
when restriction enzymes cut out DNA what do they leave?
‘sticky ends’ the base sequences separated
what does a ligase enzyme do?
helps join two strands together
what is a vector?
something that transmits something else
what is a vector usually?
bacterial DNA plasmid or a virus.
what can plasmids be used for?
inserting a desired gene into a bacterium
what are the four ways that disease can spread?
-air
-contact
-contaminated food
-contaminated water
what are the five types of virus illnesses?
HIV
measels
tobacco mosaic virus
Ebola
HPV
how is measels spread?
by water droplets from coughing or sneezing
what are the side affects of measels?
-red rash
-fever
How is HIV spread?
-through sexual contact
-exchanging bodily fluid (blood ect)
what are the symptoms of HIV?
-fever
-tiredness
-aches
what does tobacco mosaic virus affect?
plants
what are the effects of tobacco mosaic virus?
-causes patches to form on the leaves of the plant-
means the plant can’t photosynthesise:
-sugars can’t be produced for growth
what are the 4 types of bacteria illnesses?
salmonella
gonorhea
TB
crowngall
what is gonorhea?
a sexually transmitted disease spread through contact (unprotected sex)
what are the symptoms of gonorhea?
-pain when urinating
-thick yellow or green discharge from the vagina or penis
what is a treatment of gonorhea?
penicillin
what are the four types of fungi illnesses?
-thrush
-barley powdery mildew
-rose black spot
-athletes foot
what is rose black spot?
type of illness which causes purple or black spots to form on the leaves of a plant- reduces the plants abililty to photosynthesise
how is rose black spot spread?
in water or wind
how do we prevent the spread of rose black spot?
-chopping off infected leaves
-treating the plant with fungicides
what is barley powdery mildew?
fungi which causes powdery mildew to grow on barely.
can be treated using fungicides
what is athletes foot?
fungal skin infection that spreads between toes. happens due to sweat and tight shoes. Contagious!
what is crown gall?
bacterial disease that affects plants. bacteria enters the stem or root then causes plant tissues to grow differently which forms swollen glands
what is ebola?
virus which is transmitted when people come in contact with bodily fluids (vomit) No treatment!
symptoms: fevers, aches, pains
what is herd immunity?
when a large proportion of a community becomes immune to a disease. the spread from person to person becomes unlikely- so even people who haven’t been vaccinated are protected
what are the two types of cancers?
benign and malignant
what are the differences between benign and malignant cancers?
malignant cancer:
-faster growing
-aggressive
-mobile (can be spread throughout the body and tissues) - they can move around the body and cause tumours to form in other places of the body
benign:
-not cancerous (harmless) and rarely spread
-slower
-examples are warts and moles
what is the difference between bacteria and viruses?
bacteria are single -celled micro-organisms that live anywhere
viruses are smaller and can only reproduce by invading cells
what are the disadvantages of vaccines?
-they don’t always work
-they can be painful
-they can have side effects like a fever or headache
what do new drugs need to be tested for?
toxicity- how much you can take without having side effects or before you start having side effects
dosage- how much you need to take for the drug to be effective and work
what are antibiotics useful for?
clearing up bacterial infections
what can HPV develop into?
cervical cancer
how do antibiotics help cure bacterial infections?
they directly kill bacterial cells
why is antibiotic resistance becoming more common?
-doctors are prescribing antibiotics for cases where they aren’t necessary
-patients aren’t taking the full course of antibiotic’s
what is a risk factor?
something that increases the likelyhood of you getting a non communicable disease
what makes up the cardiovascular system?
-blood
-heart
-blood vessels
what problems can damaged heart valves cause?
blood can flow backwards
not enough blood will be able to pass through the valve
what are the positives of stents?
-surgery is quick
-stents can last a long time
-stents have an almost immediate effect
what happens in cornorary heart disease?
-layers of fatty material (artheomas) build up inside the cornorary arteries
-this causes the lumen to get narrower
-this reduces the flow of blood through the cornorary arteries- which means not enough oxygen and nutrients is being delivered to the heart muscle (cardiac muscle)
what are the disadvantages of statins?
-they have side effects like kidney failure and headaches
-it can be months before results can be seen
-pills have to be taken daily
why are stem cells used in medicine?
because faulty cells can cause faulty conditions- for example diabetes or anemia
however, these faulty cells can be replaced by stem cells
what is the difference between embrynoic stem cells and adult stem cells?
embryonic can differentiate into any kind of cell- but adult stem cells can only differentiate into a certain few
embryonic stem cells are found in embryos
adult stems cells are found in bone marrow
what are the steps to use embryonic stems cells in medicine?
- take the embryonic stem cells from the embryos
- grow the cells in a lab
- stimulate the cells to differentiate into any kind of cell you need
what are the drawbacks of using stem cells in medicine?
- most of the time you need only embryonic stem cells- which can differentiate into any kind of cell and they are hard to get
- your body might reject the stem cell because your body recognises the genome as foreign so it attacks it
- the stem cells might contain a virus which means a virus can be transmitted into your body
- stems cells can divide- once theyre placed in the body they divide and they might start diving uncontrolably which might cause a tumour/ cancer
what kind of stem cells don’t cause rejection?
adult stem cells- as they are taken from the patients own body
