B1.3 Inter-relationships Flashcards
What is a drug?
A drug is a chemical substance, such as a narcotic that affects the CNS.
Why can you buy some legal drugs at a pharmacy shops but need a prescription for others?
Many drugs can be dangerous if used incorrectly so they are restricted.
What is an addiction?
When you have a physical need for something and get withdrawal symptoms if you do not get that substance.
What is tolerance?
When your body gets used to a drug and you need a higher dosage to get the same effect.
What does a depressant do and what is an example?
A depressant, such as alcohol, decreases the activity of the brain. It slows down responses and increases reaction times.
What does a stimulant do and what is an example?
A stimulant, for example nicotine or caffeine, increases brain activity. It increases the number of neurotransmitters at synapses and does the opposite of a depressant.
What does a painkiller do and what is an example?
A painkiller, for example morphine, decreases the feeling pf pain by blocking nerve impulses in the brain.
What does a hallucinogen do and what is an example?
A hallucinogen, for example LSD, distorts what see and feel by altering the pathways that nerve impulses normally travel along.
What is a reaction time?
The time you take to respond to a certain stimulus. It is often less than a second.
Why is smoking tobacco harmful?
It contains carbon monoxide, which stops haemoglobin carrying enough oxygen
Tobacco contains carcinogens, like tar, which causes cancer
It is addictive due to the nicotine.
What are the short term effects of drinking alcohol?
It slows your reactions
Blurred vision
Lowered inhibitions- which can lead to you doing dangerous things.
What are the long term effects of drinking alcohol?
Cirrhosis of the liver- this is when liver cells die as a result of too much alcohol and they are replaced by scar tissue, which blocks the blood flow
Brain damage.
What is an organ transplant?
When a healthy organ taken from a donor and used to replace a damage organ in a patient.
Why are there big ethical issues surrounding organ transplants?
There is a shortage of donor organs - so only some people will get a transplant. This creates a dilemma of who gets a transplant and who has to die.
What factors may influence who gets an organ transplant and who doesn’t?
Age
Family
If they need a transplant due to their actions, or something out of their control
Benefits of the transplant.
What are pathogens?
Micro-organisms that can spread diseases.
What are the 6 ways in which a disease can be spread?
Water Food Air Contact Body fluids Animal vectors
How are pathogens transmitted in water and what is an example of a disease?
Pathogens that cause cholera live in water and it is spread when drinking water is contaminated with the diarrhoea of sufferers.
How are pathogens transmitted in food and what is an example of a disease?
Pathogens are picked up by eating contaminated food eg salmonella.
How are pathogens transmitted in the air and what is an example of a disease?
Airborne pathogens are carried in air in droplets produced when you cough or sneeze and other people breathe them in. An example is the influenza virus.
How are pathogens transmitted on contact and what is an example of a disease?
They are picked up when you touch a contaminated surface eg athletes foot.
How are pathogens transmitted in body fluids and what is an example of a disease?
They are in the body fluid and spread to the next person when they come into contact with the fluid. Examples are: Blood Breast milk Semen An example of a disease is HIV
How are pathogens transmitted by animal vectors and what is an example of a disease?
The animal vector infects humans with the disease. An example is malaria, which is spread by the anopheles mosquito.
What barriers does the body have against pathogens?
The skin is a physical barrier
The respiratory tract has mucus which traps pathogens and cilia which transport the mucus away
They eyes produce bacteria killing enzymes
The stomach contains hydrochloric acid which kills most pathogens.
How do plants defend themselves against pathogens?
They produce chemicals which can have an antibiotic like effect on the pathogen. An example is the tea tree in Australia, which produces and oil which is now used in products like facial cleansers.
What is an antiseptic?
Chemical substances that stop pathogens getting into the body?
What are antibiotics?
Chemical substances that kill or prevent the growth of bacteria or fungi.
How do bacteria become resistant to antibiotics?
One has a mutation making it resistant. All the others die out and that one survives and reproduces. Then all of the bacteria are resistant.
Why do bacteria develop resistance?
From overuse of antibiotics.
What is a food web?
The interdependence of animals in a habitat for survival.
What do the arrows in a food web show?
The direction that the energy travels in.
How is energy released in an animal?
Remains as biomass in faeces
Transferred as heat to the surroundings
Stored as biomass
How is energy lost in a plant?
Lost as heat
Reflected back to the surroundings
Stored as biomass
What is the pyramid of biomass?
A pyramid that shows the biomass of organisms in a area.
What is a parasitic relationship?
Where a parasite feeds of its hosts.
What are some examples of parasites?
Fleas
Head Lice
Tapeworms
What is a mutualistic relationship?
When two organisms, mutualists, benefit each other.
What is an example of a mutualistic relationship?
Oxpeckers and large herbivores. The oxpeckers eat parasites off of the herbivore, so they get food, and the herbivore gets rid of parasites.
What are nitrogen fixing bacteria?
Bacteria that live in the roots of legumes and turn nitrogen into nitrogen compounds. The bacteria are protected and the plants gain food.
What are the potential problems of a greater population of humans?
Raw materials are being used up
More waste is produced
More pollutants are being produced
What is eutrophication?
When nitrates and phosphates from fertilisers wash into rivers and lakes and kill the life there.
What is the process of eutrophication?
- Excess nitrates wash into river causing rapid growth of algae
- Some plants start dying due to competition for light
- Microbe numbers increase as they feed off the dead material
- Fish and aquatic animals suffocate as the microbes use up all the oxygen.
What are the benefits of recycling?
We use less raw materials
It uses less energy
Produces less waste
What are some of the disadvantages of recycling?
It still uses energy
Waste can be difficult and time consuming to sort through
The equipment needed can be expensive
The recycled product isn’t as good quality
Some materials can only be recycled a certain number of times.
What are indicator species?
Species that cannot live in clean or polluted air or water. They are used to see pollution levels.
What are some indicator species that indicate clean water?
Stonefly larvae
Freshwater shrimps
What are some indicator species that indicate polluted water?
Bloodworms
Sludgeworms
What indicator species indicate clean air?
Blackspot fungus
What does the absence of an indicator species indicate?
The opposite to what the species indicates.
In the carbon cycle, what is the only way that carbon dioxide is removed from the atmosphere?
Photosynthesis.
What are the possible stages for a carbon atom in the cycle?
Fossil fuel Carbon dioxide Carbon compound in a plant Carbon compound in an animal Carbon compound in soil Carbon dioxide
In the nitrogen cycle, how is nitrogen taken out of the atmosphere?
Lightning
Nitrogen fixing bacteria in the soil
Nitrogen fixing bacteria in roots.
How are nitrates taken out of the soil?
Absorbed by roots
Denitrifying bacteria.
What are the possible stages of a nitrogen atom in the cycle?
Nitrogen Nitrate in the soil Plant protein Animal protein Ammonia in urea Nitrate in the soil
