topic 3 Flashcards
How do pathogens affect the body?
Microorganisms that enter body and cause disease, cause communicable disease-disease that can easily spread, both plants and animals can be infected by pathogens.
What are bacteria?
very small cells (about 1/100th size of body cells) which can reproduce rapidly inside your body. Can make you feel ill by producing toxins (poisons) that damage your cells and tissues.
What are viruses?
Not cells, are tiny about 1/100th size of bacterium, like bacteria, can reproduce rapidly inside body. Live in cells and replicate themselves using cells’ machinery to produce many copies of themselves. Cell will usually then burst, releasing all new viruses, cell damage is what makes you feel ill.
What are protists?
Lots of different types of protists. But all eukaryotes, most are single-celled. Some protists are parasites. Parasites live on or inside other organisms and can cause them damage-e.g.an insect that carries the protist.
What is fungi?
Some are single-celled. Others have body which is made up of hyphae (thread-like structure). These hyphae can grow and penetrate human skin and surface of plants causing, disease. Hyphae can produce spores, which can be spread to other plants and animals.
How can pathogens be spread through water?
some pathogens can be picked up by drinking or bathing in dirty water. E.g. cholera is a bacterial infection that’s spread by drinking water contaminated with diarrhoea of other sufferers.
How can pathogens be spread through air?
Pathogens can be carried in air and can then be breathed in . Some airborne pathogens are carried in air in droplets produced when cough or sneeze-e.g the influenza virus that cases flu is spread this way.
How can pathogens be spread through direct contact?
Some pathogens can be picked up by toughing contaminated surfaces, including skin. E.g. athlete’s foot is a fungus which makes skin itch and flake off. Most commonly spread by touching same things as an infected person, e.g. shower floors and towels.
What is measles, what are symptoms and how is it treated?
is viral disease. Spreads by droplets from infected person’s sneeze or cough, people with measles develop a red skin rash, and they’ll show signs of a fever (high temperature). Measles can be very serious, or even fatal, if are complication. E.g. measles can sometimes lead to pneumonia (lung infection) or brain infection called encephalitis. Most people are vaccinated against measles when young.
What is HIV, what are the symptoms and how is it treated?
Is virus spread by sexual contact, or by exchanging bodily fluids such as blood. Can happen when people share needles when taking drugs. HIV initially causes flu-like symptoms for a few weeks. Usually, person doesn’t then experience any symptoms for several years. During this time, HIV can be controlled with antiretroviral drugs. These stop virus replicating in body. Virus can attack immune cells. If body’s immune system is badly damaged, can’t cope with other infections or cancers. At stage, virus is knows as late stage HIV infection.
What is tobacco mosaic virus (TMV), what are symptoms and how can it be treated?
is virus that affects species of plants e.g. tomatoes. Causes mosaic pattern on leaves of plant-parts of leaves become discoloured. Discolouration means plant can’t carry out photosynthesis as well, so virus affects growth.
What is rose black spot?
is fungus, causes purple or black spots to develop on leaves or rose plants. Leaves can turn yellow and drop off. Means less photosynthesis can happen, so plant doesn’t grow very well. Spreads through environment in water or by wind. Gardeners can treat disease using fungicides and by stripping plant of its affected leaves. These leaves then need to be destroyed so fungus can’t spread to other rose plants.
What is malaria?
Caused by protist. Part of malaria protist’s life cycle takes place inside mosquito. These mosquitoes are vectors-pick up malarial protsit when feed on infected animal. Every time mosquito feeds on another animal, infects by inserting protist into animal’s blood vessels. Malaria causes repeating episodes of fever. Can be fatal. Spread of malaria can be reduced by stopping mosquitoes from breeding. People can be protected form mosquitoes using insecticides and mosquito nets.
What is salmonella-type of bacteria that causes food poisoning?
Infected people can suffer from fever, stomach cramps, vomiting and diarrhoea. Symptoms caused by toxins that bacteria produce. Can get salmonella food poisoning by eating food that’s contaminated with Salmonella bacteria e.g. eating chicken that caught disease whilst alive, or unhyginically preparing food and consuming it.
Is there a a vaccination for Salmonella?
Most poultry (e.g. chickens) given vaccination against Salmonella. To control spread of disease.
What is gonorrhoea-STD?
Passed on by sexual contact. Caused by bacteria. Person with gonorrhoea will get pain when urinate. Other symptom is thick yellow discharge from vagina on penis. Gonorrhoea was originally treated with antibiotic called penicillin, but has become trickier now because strains of bacteria have become resistant to it.
How do you treat gonorrhoea?
With antibiotics and should use barrier methods of contraception e.g. condoms.
How can being hygienic prevent spread of disease?
Using simple hygiene methods can prevent spread of disease. e.g. washing hands thoroughly before preparing food of after sneezed can stop infecting others.
How can destroying vectors prevent spread of disease?
By getting rid of organisms that spread disease, can prevent disease from being passed on. Vectors that are insects can be killed using insecticides or by destroying their habitat so that can no longer breed.
How can isolating infected individuals prevent spread of disease?
If isolate someone who has communicable disease, it prevents them from passing it on to anyone else.
How can vaccination prevent the spread of disease?
Vaccinating people or animals against communicable diseases means, can’t develop infection an then pass it on to someone else.
What are examples of the body’s defence system?
Skin acts as barrier to pathogens. Also secrets antimicrobial substances which kills pathogens. Hairs and mucus in nose trap particles that could contain pathogens. Trachea and bronchi secrete mucus to trap pathogens. Trachea and bronchi are lined with cilia. These hair-like substances, which waft mucus up to back of throat where it can be swallowed. Stomach produces hydrochloric acid. This kills pathogens that make it that far from mouth.
How can your immune system attack pathogens?
Most important part of immune system is white blood cells. They travel around in blood and crawl into every part of body, constantly patrolling for microbes. When come across invading microbe, they have 3 lines of attack.
How do white blood cells consume pathogens?
Engulf foreign cells and digest them. Called phagocytosis.
How do white blood cells produce antibodies to attack pathogens?
When some types of white blood cell come across foreign antigen, will start to produce proteins called antibodies to lock onto invading cells so can be found and destroyed by other white blood cells. Antibodies produces are specific so that type antigen-won’t lock into others’ unique molecule on surface.
How do antibodies attack pathogen?
Antibodies are produced rapidly and carried around body to find similar bacteria or viruses. If person is infected with same pathogen again white blood cells will rapidly produce antibodies to kill it-person naturally immune to pathogen and won’t get ill. See revision guide.
How do white blood cells produce antitoxins to attack pathogens?
These counteract toxins produced by invading pathogen.
How long does it take for a pathogen to know what to do with a pathogen?
A few days.
What is a vaccination?
Involve injecting small amounts of dead or inactive pathogens. Carry antigens which cause body to produce antibodies to attack them-even though pathogen is harmless. E.g. MMR vaccine contains weakened version of viruses that cause measles, mumps and rubella all in 1 vaccine.
What happens if live pathogens of the same type appear in the bloodstream?
White blood cells can rapidly mass-produce antibodies to kill of pathogen.
