VIRUSES.
A virus is a very small microscopic non cellular particle that infects cells in order to multiply. They are made up of a genetic material (DNA or RNA) surrounded by a protein coat.
Viruses are not classified under any of the five kingdoms because they are nonliving. However, though viruses are not living things, they exist in nature.
Viruses behave like living things in the following ways:
- Like other living cells, a virus has genetic materials.
- Multiplies inside living cells.
- Carry out metabolism inside living cells.
- They can change (mutate) into new strains.
Also, viruses behave like non-living things in the following ways:
- Not made up of cell.
- Do not need to eat in order to live.
- Need a host cell to multiply/reproduce.
- Need a host cell to carry out metabolism.
- Crystalize and become completely inert if isolated from host cell.
Why is it hard to destroy viruses/vaccinate against them/ develop medicine that cure viral infection: why are viral pandemics so harmful? You need to understand that viral diseases are difficult to treat or have no treatment at all. Hepatitis B can be prevented by vaccination; however, Ebola and
HIV have no vaccine
Viruses are so harmful, difficult to treat or have no treatment at all because they reproduce so quickly, do not respond to antibiotics and constantly change into new strains.
viral diseases of concern include, but not limited to;
Hepatitis B virus
Ebola Virus
Tobacco mosaic Virus
Humman Immunodeficiency Virus (HIV)
Qtn; what symptoms are you familar with? do they also signify Ebola virus?
HIV weakens the immune system of the infected person making it easy to catch diseases e.g. TB (tuberculosis).
QTN; whats the difference between HIV and AIDS??
The cassava mosaic virus affects the tubers of the plant resulting in low crop yields. This virus causes the cassava mosaic virus disease. It can be recognized on the cassava leaves which have spots ranging from light green to yellow. The disease is transmitted from plant to plant by the whitefly.
This disease cannot be cured but it can be avoided. The cassava mosaic virus disease can be prevented by the use of cuttings which have not been attacked by the virus. Farmers are particularly encouraged to plant varieties which are resistant to the disease.
How the knowledge of biology can be useful in combating viral pandemics:
- Biology helps us understand the causes, modes of transmission, signs and symptoms, prevention and control of viral infections.
- Biology helps us understand how viral diseases can be managed by means a balanced diet, good nutrition and proper hygiene.
- Biology helps us understand the influence and effects of drug abuse on our bodies and its link to irresponsible sexual behavour which lead to carelessness and hence contracting viral infections.
- Biology helps us understand that cultural practices like circumcision may hinder the control of viral infections.
- Biology helps us see the need to develop safer alternative rites of passage from childhood to adulthood e.g SMC.
- Biology enhances controlled sexual and social behavour to combat viral infections.
Activity of integration;
In the recent lockdown, the country was faced with alot of economic, social and political problems due to the nature of the disease that hadcapped all activites leading to lockdown.
Task;
As a student of biology explain to your old grand mother briefly how the pandemic was handled, managed and then controlled amongst the population, clearly explaining why it spread very fast with high mortality rate.
Support material
Picture showing cyclists on empty streets of kampala during covid-19 lockdown