Topic 3 - Infection and Response Flashcards
What is a communicable disease?
A disease caused by a pathogen which can be passed between animals or plants eg. flu
What is a pathogen?
A disease-causing microorganism e.g. bacteria
How do bacteria cause disease?
Once inside the body, they divide rapidly by binary fission. They kill cells and produce harmful toxins
How do viruses cause disease?
They invade and reproduce inside living body cells, leading to cell damage
Give 3 ways pathogens can be spread
- By air
- By water
- By direct contact
Give four ways in which the spread of pathogens can be reduced?
- Hygiene
- Reducing contact with infected individual
- Removing vectors
- Vaccination
Why is it especially important to prevent the spread of viral diseases?
Scientists have not yet developed cures for many viral diseases
What is measles?
A serious viral disease that can cause blindness and brain damage. The main symptoms are fever and red skin rash
How is measles spread?
By air - through the inhalation of droplets from coughs and sneezes
What is HIV/AIDS?
- HIV is a virus which attacks and damages the immune system until t can no longer function properly
- AIDS is the condition resulting from a long-term HIV infection
- There is no cure for HIV/AIDS
How is HIV spread?
Direct sexual contact an the exchange of bodily fluids eg. blood, breastmilk
How can the spread of HIV/AIDS be prevented?
- Use of condoms
- Screening of blood transfusions
- Not sharing needles
- Bottle-feeding by HIV-positive mother
- Use of antiretroviral drugs to prevent the development of AIDS
What is tobacco mosaic virus?
- A plant pathogen which causes leaf discolouration when cells are damaged
- Affected areas cannot photosynthesise, reducing crop yield
- as there is no treatment farmers grow TMV-resistant crop strains to avoid infection
How is tobacco mosaic virus spread?
Contact between infected and healthy plants insects may act as vectors which transfer the virus between different plants
What is salmonella?
A type of bacteria found in raw meat, poultry and eggs. If they enter the body via food poisoning, they can affect natural gut bacteria
