Inter-relationships - Unit 3 Flashcards
How do drugs affect the body?
They can cause changes in physical behaviour and can be addictive.
What are drugs?
Most drugs are chemical substances that effect the central nervous system.
Which drugs are medically useful?
Antibiotics e.g penicillin
Why can’t you buy all medicinal drugs over the counter?
Because if they are misused they could be dangerous.
What happens if you don’t get the drug you’re addicted to?
You get withdrawal symptoms.
Give an example of a legal addictive drug.
Caffeine
Give an example of an illegal addictive drug.
Cocaine
What happens if your body becomes tolerant to a drug?
Your body gets used to having it so you need a higher dose to give the same effect.
What are depressants?
These decrease the activity of the brain. This slows down the responses of the nervous system, causing slow reactions and poor judgment of speed and distances.
Give an example of a depressant
Alcohol
What are stimulants?
These do the opposite of depressants - they increase the activity of the brain, by increasing the amount of neurotransmitter at some neurone synapses. This increases the speed of reactions, and makes you feel more alert and awake. Stimulant drugs are often used to treat depression.
Give an example of a stimulant.
Nicotine
Caffeine
What are painkillers?
These decrease the feeling of pain. Different painkillers work in different ways e.g morphine is a string painkiller that works by blocking the nerve impulses in the brain.
Give an example of a painkiller
Narcotics like morphine.
What are hallucinogens?
They distort what’s seen and heard by altering the pathways nerve impulses normally travel along.
Give an example of a hallucinogen
LSD
What is reaction time?
The time it takes to respond to a stimulus. It can be affected by drugs.
How do you measure reaction time?
Drop ruler test.
One person holds a ruler vertically between the thumb and forefinger of a second person.
The second person tries to catch the ruler as quickly as they can - as soon as they see it fall.
Reaction time is measured by how far down the ruler is caught - the further down, the slower their reactions.
what does the carbon monoxide in tobacco smoke do to your body?
It combines with the haemoglobin in red blood cells, so blood can’t carry as much oxygen meaning the brain becomes oxygen deprived.
what are carcinogens?
chemicals that lead to cancer.
give an example of a carcinogen in tobacco smoke.
tar.
how is tar harmful to your body?
it causes lung cancer.
which drug in tobacco causes it to be addictive?
nicotine.
what are the short term effects of drinking alcohol?
slowed reaction times
being drunk which leads to blurred vision and can lower inhibitions causing people to do things they wouldn’t normally do.
what are the long term effects of drinking alcohol?
it is poisenous so if you drink to much your liver won’t be able to break down the toxins. this causes death of liver cells, forming scar tissue that starts to block blood flow through the liver - this is called cirrhosis.
it can also lead to brain damage.
kidney damage.
give two examples of organs you can donate whilst you’re alive
a kidney
part of your liver
are there enough organ donors to supply everyone who needs an organ donor?
no
why might an alcoholic be refused a transplant at one hospital but not at another?
different hospitals have different ethnic beliefs.
might waste the organ.
could go to someone better.
would be asked to stop drinking first.
what are the reasons for people being refused transplants?
not likely to survive operation (obese)
alcoholic
harmed own organs.
what are pathogens?
pathogens are microorganisms that cause diesease. they include certain bacteria, protozoa, fungi, and viruses.
How can pathogens be spread?
water - drinking dirty water.
food - eating contaminated food.
air - carried by air in droplets produced when you cough or sneeze.
contact - touching contaminated surfaces.
body fluids - sharing bodily fluids
animal vectors - anopheles mosquito/house fly
give an example of a disease spread by water
cholera
give an example of a disease spread by food
salmonella
give an example of a disease spread by air
influenza virus
give an example of a disease spread by contact
athletes foot
give an example of a disease spread by bodily fluids
HIV
give an example of a disease spread by animal vectors
malaria/dysentery
what are the physical barriers that stop pathogens entering the body?
the skin
the respiratory system (mucus and cilia)
what are the two chemical barriers that stop pathogens entering the body?
the eyes (the lysozyme in tears) the stomach (stomach acid)
how do plants protect themselves against pathogens?
they produce chemicals that have antibacterial effects against bacteria.
what are antiseptics?
chemicals that destroy bacteria or stop them growing. we use them outside the body to help clean wounds and surfaces. they’re used to prevent infection. plenty of household products contain antiseptics e.g bathroom cleaners. antiseptics are used in hospitals and surgeries to try to prevent the spread of infections like MRSA.
what are antibiotics?
antibiotics are drugs used inside the body, usually taken as a pill or injected. they are used to treat patients who are already infected with bacteria or fungi. however antibiotics don’t destroy viruses.
what are the two types of antibiotics?
antibacterials
antifungals
what are antibacterials?
they are used to treat bacterial infections. they work by killing bacteria or by stopping them growing. however bacteria can evolve resistance to certain antibacterial antibiotics meaning the antibiotics don’t work any more.
e.g penicillin.
what are antifungals ?
used to treat fungal infections
they work by killing the fungi or stopping them growing.
e.g nystatin
how do bacteria become resistant to antibiotics?
bacteria can mutate - sometimes mutations cause the to be resistant to antibiotics. if you have an infection, some of the bacteria might be resistant to antibiotics. this means when you treat the infection, only the non-resistant strains of bacteria will be killed. the individual resistant bacteria will survive and reproduce, and the population of the resistant strain will increase. this is an example of natural selection. the resistant strain could cause a serious infection that can’t be treated by antibiotics e.g MRSA causes serious wound infections and is resistant to antibiotics.
what increase the chances of being resistant to bacteria?
misusing antibiotics will develop resistant strains.
how do you test which antibiotic is better against a certain bacteria?
grow that bacteria in a petri dish with discs of different antibiotics on. let it grow for a few days. measure the zone of inhibition around each disc. the bigger the zone of inhibition the better the antibiotic is.
what is the source of energy for most things on earth
the sun
does all the energy transfer to the end of the food chain?
no animals use some of the energy in respiration, in animal droppings or lost to the surrounding environment.
what is a pyramid of biomass?
it is a graph to show the creatures at each level of a food chain would weigh if you put them together. it shows how much energy is at each stage in the food chain.
what is parasitism?
a feeding relationship in which two organisms live together, one feeding off the other. the parasite feeds off the host. the host will be harmed.
give two examples of parasites
flea
head lice
tape worm
mistletoe
what is mutualism?
a feeding relationship when two organisms live closely. Both the organisms benefit from this.
give two examples of mutualists
oxpecker
cleaner fish
nitrogen-fixing bacteria in legumes
chemosynthetic bacteria in deep-sea vents
how does the growing population effect the earth?
acid rain.
global warming.
eutrophication.
what is eutrophication?
this is when inorganic fertilisers containing nitrates get washed into lakes. this causes more plants to grow causing overcrowding so the plants don’t get enough sunlight and therefore die. the increase in dead materials means that there are more microorganisms and bacteria which use up the oxygen causing fish to die.
what is acid rain.
it is caused when power stations burn fossil fuels and produce sulphur dioxide. this dissolves in water vapour to form acid rain which can make lakes acidic, damage buildings, and damage statues.
how does the population boom cause global warming?
we burn a lot of foosil fuels, chop down trees, and have a lot of livestock. this means we produce a lot of CO2 and and methane which adds to the green house effect, increasing the global temperature.
what is an indicator species?
it is a species that are very sensitive to changes in their environment and so can be studied to see the effect of human activities.
give two examples of air pollution indicators.
blackspot fungus
lichen
what is the blackspot fungus?
this is an infection in roses that absorbs suphur dioxide and gets killed. only found in areas with clean air.
where is lichen found?
in areas with clean air.
what are the indicator species for water pollution?
bloodworm
sludgeworm
freshwater shrimp
stonefly shrimp
which indicator species are found in clean water?
freshwater shrimp and stonefly shrimp.
which indicator species are found in polluted water?
bloodworm and sludge worm.
what are the non living indicators?
nitrogen test
oxygen test
phosphate test.
what are the 5 processes in the carbon cycle?
combustion - when we burn fossil fuels to produce CO2
respiration - when living organisms respire to produce CO2
photosynthesis - when plants photosynthesise to produce O2
decomposition - plants and animals eventually die and decay. they then get broken down by bacteria and fungi which respire and release CO2.
eating - we eat plants which passes the carbon compounds along to animals in a food chain.
what are the four types of bacteria in the nitrogen cycle?
decomposer bacteria
nitrifying bacteria
nitrogen-fixing bacteria
dentrifying bacteria
what is decomposer bacteria?
it decomposes proteins and urea and turns them into ammonia.
what is nitrifying bacteria?
it turns ammonia in decomposing matter into nitrates.
what is nitrogen-fixing bacteria?
it turns the nitrogen in the atmosphere into nitrogen compounds that plants can use.
what is denitrifying bacteria?
it turns the nitrates back into nitrogen gas. this is of no benefit to living organisms.
