B5 Flashcards
What are pathogens?
Microorganisms that enter the body and cause disease. Both plants and animals can be infected
What type of disease to pathogens cause?
Communicable diseases.
What are communicable diseases?
Diseases that can spread
What forms do pathogens come in?
Virus
Bacteria
Protist
Fungi
How can pathogens be spread
- water
- air
- direct contact
What are bacteria ?
- very small living cells that can reproduce rapidly inside the body.
- they make you feel ill by producing toxins that damage cells and tissues
What are toxins?
Poisons
What are viruses?
- not cells
- very small
- reproduce rapidly
- live inside the cell , replicate themselves using cells machinery to produce copies of themselves . The cell will usually burst releasing all the new virus
- cell damage makes us feel ill
What are protists?
- eukaryotic
- single celled
- many types
- can be parasites . Parasites live in or on other organisms and can cause them damage . They are often transferred to another organism by a vector.
What are fungi?
- single celled
- hyphae (thread like structure) can grow and penetrate human skin and surfaces of plants
- hyphae can grow into spores , which can be spread to other plants and animals
What is measles?
- viral disease
- spread by droplets from a sneeze or cough
- develop red skin rash and shows signs of a fever
- can be very serious and even fatal, if there are complications.
- most people are vaccinated against measles when they’re young.
What is HIV?
- viral disease
- HIV initially causes a flu like illness .
- unless successfully controlled with antiretroviral drugs the virus attacks the bodys immune system.
- AIDs occurs when the bodys immune system becomes so badly damaged it can no longer deal with other infections or cancers.
- spread by sexual contact or exchange of bodily fluids such as blood of drug users
What is tobacco mosaic virus ?
- viral disease
- TMV
- widespread plant pathogen affecting many species of plants including tomatoes.
- gives distinctive mosaic pattern of discolouration on the leaves which affects the growth of the plant due to lack of photosynthesis
What is salmonella?
- bacterial disease
- food poisoning spread by bacteria ingested in food or on food prepared in unhygienic conditions.
- poultry in uk is vaccinated against salmonella to control the spread
- fever , abdominal cramps , vomiting and diarrhoea are causd by bacteria and the toxins.
What is gonorrhoea ?
- bacterial infection
- sexually transmitted disease
- thick yellow discharge from vagina or penis, also pain when urinating
- caused by bacterium and was treated easily with antibiotic penicillin until resistant strains appeared
- spread by sexual contact
- spread can be controlled with antibiotics or use of a barrier method of contraception such as a condom.
What is rose black spot?
- fungal disease
- purple or black spots develop on leaves , which often turns yellow and drops early .
- effects the growth of the plant as photosynthesis is reduced . It is spread in the environment by water and wind .
- treated by destroying infected plants and fungicides
What is malaria?
- protist disease
- carried by a vector (mosquito) to a person
- causes recurrent episodes of fever and can be fatal
- can stop it by preventing the vectors, mosquitos from breeding and using mosquito nets to avoid being bitten.
How to reduce or prevent the spread of pathogen?
- being hygienic
- destroying vectors
- isolating infected individuals
- vaccination
How does the skin act as a defence system?
Acts as a barrier to pathogens . It also secretes antimicrobial substances which kill pathogens
How hair and mucus in the nose works as a defence system?
Trap particles that could contain pathogens
How the trachea and bronchi are a defence system for the body?
Secrete mucus to trap pathogen . Lined with cilia . These are hair like structures , which waft the mucus up to the back of the throat where it can be swallowed
How is the stomach a defence system?
Produces hydrochloric acid . Kills pathogens that make it far from the mouth
What is the most important part of the immune system?
White blood cells
What do white blood cells do?
They travel around in your blood and crawl into every part of you , constantly patrolling for microbes. When coming across microbes they have three lines of attacks
What is a phagocyte?
- white blood cell
- engulfs foreign cells and digests them
What is the lymphocytes?
White blood cell that produces antibodies
How do lymphocytes product antibodies?
- every invading pathogen has a unique molecule called antigens on its surface which helps white blood cells detect them
- when some white blood cells come across a foreign antigen they will produce proteins called antibodies to lock into invading cells and destroy the, anti bodies produced are specific to each antigen
- antibodies are then produced rapidly and carried around the body to find similar bacteria
- if the same pathogen invades again white blood cells will rapidly be produce antibodies to kill it. Person is immune and wont get ill
What is the immune system?
The defence system of humans
What are anti toxins?
Produced by white blood cells to counteract toxins produced by invading pathogen
