Diseases & viral diseases Flashcards
State the two types of disease
Types of disease
Communicable
Non-communicable
Define communicable disease
Communicable disease is a disease able to be transmitted from one sufferer to another; contagious or infectious
Define Non-communicable
Non-communicable disease is a medical condition or disease that is non-infectious or non-transmissible
Define the term ‘health’
Health is a state of physical and mental well-being
How is ill health caused
Ill health can be caused by both communicable and non-communicable diseases
It can also be caused by poor diet, high levels of stress and other life-situations e.g. working with harmful chemicals
How health problems interact
Viruses living in cells cells can trigger changes that lead to cancers 0 e.g. the human papilloma virus can cause cervical cancer.
People with a defective immune system are much likely to suffer from infectious diseases such as HIV/AIDS
Immune reactions initially caused by a pathogen, can trigger allergies to factors in the environment. These allergies may cause skin rashes, hives or asthma.
Physical and mental health are often closely linked. Severe physical ill health can lead to depression and other mental illnesses
What are communicable disease spread by
Communicable diseases are spread by pathogens
What causes infectious disease
Infectious diseases are caused by microorganism - pathogen
List the 4 types of pathogens
Viruses
Bacteria
Fungi
Protists
Which microorganisms cause the majority of communicable disease in humans
Bacteria and Viruses
Which microorganisms cause the majority of communicable disease in plants
Viruses and Fungi
Describe the structure of viruses
Viruses usually have a regular shape
Complete the sentence
_______ cause disease in every type of living organism
Viruses cause disease in every type of living organism
How do bacteria cause disease
Once inside the human body, bacteria divide rapidly by splitting in two (called binary fission).
Bacteria can then release harmful chemicals called toxins.
Toxins damage tissues and make us feel ill.
Explain why viruses are different to bacteria
Unlike bacteria viruses cannot reproduce by themselves. They can only reproduce inside a host cell.
How do viruses cause disease
Viruses take over the cells of your body. They live and reproduce inside the cells, damaging and destroying them.
The virus invades the host cell and then reproduces inside the host cell
This is very damaging to the cell.
When the virus leaves the cell, it can cause the cell to burst open and die.
How can pathogens spread
Pathogens can spread:
By air
Direct contact
By water
Example of pathogens spread by air
e.g. in water droplets (influenza)
When you are ill, you expel
Example of pathogens spread by direct contact
e.g. HIV
Example of pathogens spread by water
e.g. cholera
How to prevent the spread of pathogens
Hand washing - especially after using the toilet, before cooking or after contact with an animal or someone who has an infectious illness
Using disinfectants on kitchen work surfaces, toilets etc. to reduce the number of pathogens
Keeping raw meat away from food that is eaten uncooked to prevent the spread of pathogens
Couching or sneezing into a handkerchief, tissue or your hands (and then washing your hand)
Maintaining the hygiene of people and agricultural machinery to help prevent the spread of plant diseases.
`Define the term pathogen
Pathogens are microorganisms that cause infectious disease
State some examples of viral diseases
Measles
HIV - develops into AIDS
Tobacco Mosaic Virus
State the symptoms of measles
A fever and a red skin rash
What is the prevention/treatment of measles
No treatment
An infected person needs to be isolated to stop the spread of the virus
Vaccination
State the method of transport of measles
The measles virus is spread by inhalation of droplets from sneezes and
coughs. (airborne)
When does AIDS occur
AIDS occurs when the body’s immune system
becomes so badly damaged it can no longer deal with other infections or cancers
What is aids
Aids is late-stage HIV
State the symptoms of HIV/AIDS
Mild, flu-like illness
State the method of transport of HIV/AIDS
HIV is spread by sexual contact or exchange of body fluids
such as blood which occurs when drug users share needles.
State the prevention/treatment of HIV/AIDS
Use condoms
Not sharing needles
Screening blood use for transfusions
PreP( a drug that stops viruses from reproducing)
State the symptoms of TMV
A distinctive ‘mosaic’
pattern of discolouration on the leaves
State the method of transport of TMV
Spread by the contact between diseased plant material
Contaminated equipment/handling
Prevention/Treatment of TMV
No treatment
Farmers grow TMV-resistant strains of many crop plants
Good field hygiene and good pest control can help prevent the spread of TMV
Burning affected plants
What does TMV do
Give an example of plant species affected by TMV
TMV gives a distinctive ‘mosaic’
pattern of discolouration on the leaves which affects the growth of the
plant due to lack of photosynthesis.
EXAMPLE: Tomatoes
