Diseases Flashcards
What are microorganisms?
Group of tiny organisms
What do Microorganisms include?
Bacteria, Viruses, Protists and Fungi
What are bad microorganisms called?
Pathogens
What is a pathogen?
A microorganism that can cause disease
What type of disease do pathogens cause?
Communicable diseasesW
What is a communicable disease?
A disease that can spread from person to person
Give two ways pathogens spread and explain how.
Any two from:
1. Through the air, when we cough, tiny droplets of the pathogen is expelled from our body.
2. Contaminated food and water, if water was contaminated and you drank it you would get the disease.
3. Direct contact, touching the contaminated surface
How can we stop disease spreading?
We can be hygienic by washing our hands and cleaning cookery utensils. Killing the disease vector, vaccination and quarntine
What is a disease vector?
Something that caries the disease, for example Mosquitoes transporting Malaria
What is the best way to kill vectors?
To vaccinate everyone
Are viruses living creatures?
No
Are viruses cells?
No
How many times smaller than a cell is a virus?
10,000 times smaller
How do viruses reproduce?
They use the cell’s machinery to make copies of themselves.
What are the 2 ways a virus can reproduce?
The Lytic Pathway and the Lysogenic pathway
What are the body’s two defense systems?
- Stopping pathogens getting into the body
- Killing pathogens if they enter the body
What is the main cell in the immune system?
The white blood cell
What defence mechanisms does the skin have?
- Covering our body, the physical barrier stops the pathogens from entering the body
- Releases oils and antimicrobial chemicals that kill any pathogens.
As the pathogens can’t enter from the skin, where can they enter our body from?
They enter from holes such as the nose and the mouth.
How is the nose adapted to stop pathogens from entering?
- Nose has hairs that catch pathogens trying to enter.
- Also has mucus that trap pathogens
If pathogens get through the nose, what two tubes can it go down?
The trachea and the esophagus
How is the trachea adapted to stop pathogens getting further into the body?
- Has mucus which traps pathogens. Also, to stop it building up, there are cilia hairs that move pathogens to the throat where we can swallow them.
How is the stomach adapted to kill pathogens?
Produces Hydrochloric acid that has a very low pH and is very acidic that can kill pathogens
What is phagocytosis?
When a white blood cells destroys a pathogen by engulfing it
Why do we fill sick when pathogens enter our body?
They produce toxins
What are toxins?
Mini posions to the cell
What are the three ways White Blood cells protect us?
They carry out phagocytosis, they produce anti toxins and they produce anti bodies.
What do antibodies do?
They track down pathogens and attach to them, acting as a signal for the white blood cell to come and carry out phagocytosis
What type of white blood cell can carry out phagocytosis?
Phagocytes
What are the four ways a disease can spread?
-through air
-through water
-through direct contact
-through contact of body fluids
What are antibodies?
Proteins
How quickly do bacteria reproduce?
Every 20 minutes
What are the 4 stages of the reproduction of a virus?
adsorption, penetration, replication and release
What is adsorption?
When a virus genome attaches (binds) to a host cell
What is penetration?
When the virus injects it’s DNA into the cell, and makes it produce more viruses
What is replication?
When the DNA of the virus takes over the cell and makes more virus particle
What is the release stage?
When the virus bursts out of the cell
What is the spreading of disease called?
Transmission
What are lymphocytes?
White blood cells which attack pathogens by producing antibodies and anti toxins
What are thr two types of lymphocytes?
B and T lymphocytes
What do B-Lymphocytes do?
Produce antibodies
What do T-Lymphocytes do?
Destroy cells infected by pathogens
What are memory cells?
Cells that recognise thr same pathogen when it invades to produce large amounts of antibodies
What do antitoxins do?
Neutralise toxins
What are two symptoms of measles?
Fever, red rash
What types of pathogen causes measles?
Virus
How can you catch measles?
Inhalations of droplets from sneezes or coughs
How does a bacteria become resistant to the antibody?
There will be random mutations in the DNA of the bacteria, causing it to be resistant to the antibody. All the other bacteria will die as the bacteria will kill them, and the bacteria that had the mutations will survive and reproduce, passing its genes along. Over time, this will carry on happening until all the bacteria are resistant
