Describe the steps involved in biological method taking malaria as an example.

Describe the steps involved in biological method taking malaria as an example.

Study of malaria

Malaria is a common disease in many countries including pakistan.Malaria has killed more people than any other disease.

History of malaria

More than 2000 years ago,physicians were familiar with malaria. They described it as a disease of chills and fevers with recurring attacks.

Naming of malaria

Old physicians obseved that the disease was more common amongst people living in low marshy areas. It was thought that the stagnant water of marshes poisoned the air and as a result of breathing in this "bad air", people got malaria.

This belief led to the name of the disease.The word "malaria" is the commbination of two ltalian words:

"mala"means"bad"

"aria"means"air"

Some volunteers drank the stangnant water from the marshes.They did not develop malaria.

Discovery of Quinine

In the seventeenth century, the new world was discovered.Many plants from America were sent back to europe to be used as medicines.The bark of a tree known as Quina quina was very suitable for curing fevers.It was so benefical that soon it was impossible to carry enough bark to europe.

Some dishonest merchants began to substitute the bark of another tree, the Cinchona which closely resembled Quina quina.This dishonesty proved much profitable for mankind.The Cinchona bark was found to be excellent for treating malaria as its bark contains quinine that is effective in treating the disease.

Discovery of plasmodium

At that time physicians treated malaria with cinchona without understanding the cause of malaria.Two hundred years later,it was found that some diseases are caused by tiny living organisms.After this discovery,it also became a belief that malaria,too,might be caused by some microorganisms.

In 1878 a french army physicians laveran began to search for the "cause"of malaria.He took a small amount of blood from a malarial patient and examined it under microscope.He noticed some tiny livimg creatures.His discovery was not believed by other scientists but two years later another physician saw the same creatures in the same creatures in the blood of another malaria patient.Tree years later after the second discovery the same creatures were observed for third time.The organism was given a name "malarial parasite"and than plasmodium.