Topic 3- Problems of, and Solutions to, a Changing Environment Flashcards
What are drugs?
Drugs are chemical substances that affect the central nervous system, causing changes in psychological behaviour and possibly addiction.
What are opiates?
Opiates are drugs that come from poppy plants.
What are the 4 types of drugs?
- stimulants
- depressants
- painkillers
- hallucinogens
How do the 4 types of drugs affect neurotransmission?
- stimulants speed up the transmission of a message across a synapse.
- depressants slow down the transmission of a message across a synapse.
- painkillers precent the transmission of a message across a synapse.
- hallucinogens block pathways to the sensory pathways to the brain.
What are illegal and legal examples of the 4 types of drugs?
stimulants: legal- caffeine, nicotine. illegal- cocaine, speed
depressants: legal- alcohol. illegal- barbiturates, solvents
painkillers: legal- paracetamol. illegal- heroin
hallucinogens- legal- (legal highs?) illegal- LSD
What are solvents?
Solvents are depressants that give off different kinds of vapours.
What is alcohol?
Alcohol is a depressant that contains the chemical ethanol.
What is tobacco?
Tobacco is the substance in cigarettes that contains tar and nicotine, and produces carbon monoxide when smoked.
What are the physical and mental effects of a solvent when inhaled?
Physical effect - can cause permanent damage to the lungs, liver, brain and kidneys
Mental effect - causes hallucinations, alter behaviour and personality
What are the physical and mental effects of alcohol?
Physical effect - can cause brain and liver damage (cirrhosis) and blurred vision
Mental effect - can cause depression, and can lead to loss of inhibitions and self-control
What are the physical and mental effects of tobacco?
Physical effect - carbon monoxide absorbed by the haemoglobin in red blood cells more easily than oxygen.
Can lead to: emphysema (alveoli walls break down), build up of mucus, bronchitis, cancer caused by tar, increased heart rate and blood pressure.
Mental effect - nicotine is addictive
What is a carcinogen?
A carcinogen is a chemical that causes cancer.
What is the carcinogen in cigarettes?
Tar is the carcinogen in cigarettes.
What is a transplant?
A transplant is when an organ or tissue is moved from one patient to another or from one part of a patient to another.
What are examples of some organs that can be transplanted?
Hearts, kidneys, livers, lungs, intestines, pancreases
What are examples of some tissues that can be transplanted?
Skin, bones, tendons, corneas, heart valves and veins.
What are 3 ethical issues of organ transplants?
- Voluntary or mandatory donation (should people have to give organs when they die or should they make the conscious decision when they are alive)
- Should people who may have had some control over their condition be allowed to have transplants (eg. liver transplants for alcoholics)
- Theft of, and then illegal trade of, organs (trafficking/black market)
What are pathogens?
Microorganisms that cause disease.
What are the 4 types of pathogens?
Bacteria, Fungi, Viruses, Protozoan
What are 2 examples of diseases that each of the 4 types of pathogens cause?
Bacteria - salmonella, tuberculosis
Fungi - ringworm, athlete’s foot
Viruses - Influenza, HIV
Protozoan - malaria, ?
What is the most common method of transmission of pathogens?
Indirect contact
What disease is caused by drinking dirty water?
Cholera
What disease is caused by eating uncooked meat?
Salmonella (food poisoning)
What disease is airborne?
Influenza
What disease is caused by a vector?
Malaria (mosquito), dysentery (housefly).
What disease is caused by direct contact?
Athlete’s foot fungus
What disease is caused by the exchange of body fluids?
HIV
How do some plants protect themselves from being attacked from pathogens?
They make protective chemicals.
Where is aspirin found naturally and what is it used for?
Aspirin is found in the bark and leaves of willow plants and is used as pain relief
Where is taxol found naturally and what is it used for?
Taxol is found in the bark of the Pacific yew tree and is used as treatment of some forms of cancer
What are the 3 physical barriers that animals use to defend themselves?
- skin
- cilia
- mucus
What are the 2 chemical barriers that animals use to defend themselves?
- lysozymes
- hydrochloric acid
What are antiseptics?
Antiseptics are substances that are applied to surfaces, and commonly, broken skin, to prevent infection by microorganisms.
What are examples of frequently used antiseptics?
Alcohol, iodine and salt
What are antibiotics?
Antibiotics are medicines that kill or inhibit the growth of bacteria or fungi.
What was the first antibiotic to be discovered?
Penicillin
What is a superbug?
A superbug is a bacteria that has become resistant to antibiotic medicines.
What is MRSA?
A superbug, MRSA stands for methicillin-resistant Staphyloccucus aureus.
Why is MRSA a particular problem in hospitals?
Because people with weakened immune systems are at greater risk.
Why is it important to take a full course of antibiotics in order to kill a bacterial infection?
Because if you do not take a full course, then the bacteria will have time to evolve and become resistant to the antibiotics.
What is interdependence?
Interdependence refers to a relationship between organisms whereby organisms depend on each other for some resource or for survival.
What is a food chain?
A food chain is a chain that shows the feeding relationship between organisms in an ecosystem.
What a trophic level?
Each stage in a food chain or food pyramid
What is parasitism?
A relationship between two organisms where an infecting parasite benefits directly from its host.
What is mutualism?
A relationship between two organisms where both organisms benefit from the relationship.
What are examples of parasites?
Mistletoe, fleas, ticks, headlice, tapeworms
What are examples of mutualistic relationships?
Oxpecker birds and large mammals, cleaner fish and larger fish, chemosynthetic bacteria in tube worms, and nitrogen-fixing bacteria in the root nodules of legumes
What are problems caused by the overpopulation of the world?
Global warming, extinction of animals and plants, and pollution
What may air pollution consist of?
Hydrocarbons, carbon dioxide, sulfur dioxide, carbon monoxide
What is pollution?
Pollution is the contamination of the environment by waste substances, produced as a result of human activity
What may water pollution consist of?
Sewage (human waste), Nitrates, Phosphates
What is an indicator species?
An indicator species is a species whose presence is an indicator to scientists of how polluted an area is.
What are examples of indicator species that indicate low levels of air pollution?
blackspot fungus on roses, lichens
What are examples of indicator species that indicate high levels of water pollution?
sludgeworms, bloodworms, rat-tailed maggots
What are examples of indicator species that indicate low levels of water pollution?
mayfly larvae, freshwater shrimp, stonefly
What are the main processes in the carbon cycle?
- photosynthesis
- consumption
- respiration
- decay
- combustion
What are the main processes in the nitrogen cycle?
- nitrogen fixation
- nitrification
- denitrification
- decomposition
- death
- excretion
Where are nitrogen-fixing bacteria found?
Some are found in the soil, some are found in the root nodules of legumes
What is the role of nitrifying bacteria in the nitrogen cycle?
They convert ammonia to nitrates in the soil
What is the role of nitrogen fixing bacteria in the soil and in the roots of legumes?
They convert atmospheric nitrogen into ammonia in the soil.
What is the role of denitrifying bacteria in the nitrogen cycle?
They convert nitrates into atmospheric nitrogen.
What is nitrogen fixation?
The process of converting atmospheric nitrogen into ammonia
What is denitrification?
The process of converting nitrates into atmospheric nitrogen
What is nitrification?
The process of converting ammonia into nitrates
What is the name for microorganisms that break down the dead animals and plants in the nitrogen cycle?
Decomposers
What is eutrophication?
The process whereby fertilisers leak into nearby streams or rivers, causing death of underwater plants and animals.
What is another way that atmospheric nitrogen can be converted into nitrates other than nitrogen fixation and nitrification?
Lightening strikes can convert nitrogen gas into nitrates that are put into the soil.
