B3 - Infection And Response Flashcards
What are pathogens?
Microorganism that enter the body and cause disease
What are the four types of pathogen?
Bacteria, viruses, protists and fungi
How small are bacteria cells compared to our body cells?
1/100th of the size of our body cells
How do bacteria make us feel ill?
They produce toxins that damage cells and tissues
How small are viruses compared to bacteria?
1/100th the size of a bacterium
How do viruses make us feel ill?
They invade our cells and replicate themselves using our cell’s machinery. When there is lots of them, the cells will burst and this cell damage makes us feel ill
Are protists eukaryotic or prokaryotic?
Eukaryotic
What is the most common type of protist?
Parasites
What do parasites do?
They live on an organism called a vector which doesn’t get the diseased. Then it is transferred to the victim organism and lives either in or on and causes damage
Name a vector.
Insects, rats
How many cells do most protists have?
One
What are the two structures that fungi can come in?
Single-called or thread-like hyphae
How do hyphae fungi spread?
Producing spores
How do hyphae fungi get into organism to cause disease?
They can penetrate surfaces of skin and plants
What are the three main ways pathogens can be spread?
Water, air, contact
What are the three viral diseases you have to know about?
Measles, HIV and the Tobacco Mosaic Virus
How is measles spread?
Air - droplets when the infected sneeze or cough
What are the symptoms of measles?
Rash, fever
What two things can measles lead to that makes it a potentially fatal disease?
Pneumonia and the brain infection encephalitis
How is measles generally prevented in Britain?
NHS vaccinations for young children and babies
How is HIV spread?
Exchanging bodily fluids
What are the symptoms of HIV?
Flu-like
What type of cells does the HIV virus attack and damage?
Immune system cells
What happens if the HIV virus badly affects someone’s immune system?
They cannot cope with other infections or diseases properly
What is HIV known as in its more serious, later stages?
AIDS
What does the Tobacco Mosaic Virus affect?
Plants
What are the symptoms of TMV?
A discoloured mosaic pattern on the leaves
What the discolouration mean for the plant?
Photosynthesis, and therefore growth, is badly affected
What is the fungal disease you have to know about?
Rose black spot
What does rose black spot affect?
Rose plants
How does rose black spot spread?
Water or by wind
What are the symptoms of rose black spot?
Purple or black spots on leaves, then leaves turn yellow and fall off
What the discolouration of the leaves during rose black spot mean for the plant?
Photosynthesis, and therefore growth, is affected badly
How is rose black spot treated by farmers? (2)
Fungicides, or cutting off and destroying infected leaves on a plant
What is the protist disease that you have to know about?
Malaria
What is the vector for malaria?
Mosquitos
What are the symptoms of malaria?
Episodes of fever
How can malaria be prevented?
Insecticides, mosquito nets
What are the two bacterial diseases you need to know about?
Salmonella and gonorrhoea
How is salmonella spread?
Food
How does food get the salmonella bacteria?
Either by catching it when alive in meat, or by being kept in unhygienic conditions
What are the symptoms of salmonella?
Fever, stomach cramps, vomiting, diarrhoea
