4.1 Communicable Diseases Flashcards
How does skin protect the body?
Acts as a barrier. Preventing pathogens entering the body.
What is the skin made of?
Outer layer is 90% Keratine. This dries and forms hard keratin.
What is sebum?
Oily substance on the skin that inhibits pathogen growth.
What is skin Flora?
The large amounts of skin cells out compete the pathogens.
What is a pathogen?
An organism that causes disease
What does a pathogen do?
Lives in and takes nutrients from a hosts body. Causing damage in the process.
What are the main types of pathogen?
Bacteria. Virus. Fungi. Protist.
What are communicable diseases?
Diseases that can be spread between organisms. Caused by one organism infecting another.
What is bacteria?
A prokaryotic unicellular organism that can cause disease. Not all bacteria cause disease though.
Why are bacteria bad for organisms?
Reproduce rapidly (some duplicate every 20 minutes). Produce toxins and waste products that damage the host.
What bacterial disease is found in plants?
Ring Rot
What is Ring Rot?
Wilting in lower leaves in Potato and tomato plants. Leaves roll inwards and leaf becomes a dull green. Vascular tissue then decays.
What is tuberculosis?
A Bacterial disease that usually attacks the lungs. Tissues and cells are killed. leading to respiratory issues.
How is tuberculosis spread?
Coughing and sneazing (droplet infection).
What is Bacterial Meningitis?
A bacterial disease that damages the membranes around the brain and spinal cord.
What are the symptoms of Bacterial Meningitis?
Fever. Stiff Neck. Headache. Nausea. Vomiting.
How is Bacterial Meningitis spread?
Coughing and sneezing (Droplet infection).
What bacterial diseases are found in animals?
Tuberculosis. Bacterial Meningitis.
How is Ring Rot spread?
Droplets and vectors
What is gram positive bacteria?
Bacteria that goes blue-purple when stained with gram stain.
Why does gram positive go this colour?
It goes blue-purple as it has a thick cell membrane.
What is gram negative bacteria?
Bacteria that goes red after gram staining.
What type of bacteria is most resistant?
Gram negative. More resistant to antibodies and drugs.
What is a virus?
A short section of RNA surrounded by proteins. All viruses are pathogens. Viruses carry out no life processes and are therefore not classified as living.
How do viruses cause infection?
They insert their RNA into the DNA of a host cell. This causes the cell to produce lots of viruses.
What are viruses that infect bacteria called?
Bacteriophages
What are the viral infections in animals?
Influenza. HIV/Aids.
What is Influenza?
A viral attack on the respiratory system.
What are the symptoms of Influenza?
Coughing. sore throat. runny nose. muscle pain and headaches.
How is Influenza spread?
Droplet infection.
What is HIV?
A viral disease that attacks the immune system and makes you more susceptible to other everyday diseases.
What does HIV stand for?
Human Immunodeficiency Virus
What is AIDS?
The name given to the life threatening diseases contracted due to the weakened immune system caused by HIV
What does AIDS stand for?
Acquired Immune Deficiency Syndrome
How is HIV/AIDS spread?
Direct physical contact
What is tobacco mosaic virus?
A viral disease that causes a mosaic of brown spots to appear on the leaves of plants. This prevents photosynthesis taking place. It usually doesn’t kill the plant, just stunts the growth.
How is tobacco mosaic virus spread?
Direct physical contact.
What viral disease is found in plants?
Tobacco mosaic virus
What is fungi?
Decaying matter. Eukaryotic cells but can be unicellular or multicellular.
How does fungi cause problems in plants?
It infects the vascular system and enters the leaves preventing photosynthesis. It also produces millions of spores that infect other organisms.
What is Ring Worm?
A fungal disease that commonly affects cattle but can be spread to humans. It causes a rash on the skin.
How is Ring worm spread?
Direct contact.
What is black sigatoka?
A fungle disease that affects bananas. Causes a reduction in leaf area and premature ripening. leading to a yeald loss (50%).
How is black sigatoka spread?
Direct contact and vectors.
What is athletes foot?
A fungal disease that affects the skin on the feet.
How is athletes foot spread?
Direct physical contact. Can spread to toe nails and hands.
What is a protist?
A eukaryotic cell that can be unicellular or multicellular.
How does a protist cause damage?
Usually causes harm when entering the host cell. It feeds on the host cell and grows.
What is maleria?
A protist disease that affects a person’s liver and blood. Within 24 hours can cause severe illness and potentially death!
What are the symptoms of maleria?
Fever. headache and chills.
How is maleria spread?
Vectors - female anthepeles mosquitos.
What is blight?
A protist disease that affects potato’s and tomatos. Causes collapse and decay.
How is blight transmitted?
Through contact of foliage and tubers of fruit in wet weather.
How do viruses cause damage?
Take over cellular metabolism and insert viral genetic material into the host cell. They reproduce rapidly and cause the cell to burst. destroying it.