EXPLAIN BIOLOGICAL METHOD WITH AN EXAMPLE OF MALARIA
MALARIA
Malaria is a serious and sometimes fatal disease caused by a parasite that commonly infects a certain type of mosquito which feeds on humans. People who get malaria are typically very sick with high fevers, shaking chills, and flu-like illness. Four kinds of malaria parasites infect humans: Plasmodium falciparum
OBSERVATIONS ABOUT MALARIA
1. DISEASE OF CHILLS AND FEVER
In ancient times, physicians were familiar with this disease.They described it as a disease of chills and fever with recurring attacks. They observed that the disease was more common among people living in low marshy areas.
2.ASSOCIATION OF MALARIA WITH MARSHY PLACES
It was thought that stagnant water of marshes poisoned the air and as a result of breathing in this "bad air", people got malaria. This belief lead to the name of disease " malaria".
3. MEANING OF MALARIA
A combination of two italian words ." THE ITALIAN WORD FOR "BAD"is MALA and " air" is " aria"
4. MARSHES AND MALARIA
Some volunteers drank the stagnant water from the marshes . they did not develop malaria.
5. TREATMENT OF MALARIA BY USING CINCHONA BARK
In 17th century, 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.
Some dishonest merchants began to substitute the bark of another tree " cinchona" which closely resembled quina-quina .This dishonesty proved much valuable for mankind.
6. WORK OF LAVERAN
In 1878, a french army physician laveran began to search the cause of malaria.he took a small amount of blood from malarial patient and examined it under microscope. He noticed tiny living creature.The organism was given a name " plasmodium'
7.FOUR MAJOR OBSERVATIONS ABOUT MALARIA
- Malaia and marshy areas have some relatiom
- quinine is an effective drug for treating malaria
- Drinking water of marshes does not cause malaria
- Plasmodium is seen in the blood of malarial patients.
HYPOTHESIS
- The hypothesis made regarding malaria was " plasmodium is the cause of malaria"
DEDUCTION
- Following deduction is drawn from the above mentioed hypothesis. " if plasmodium is the cause of malaria then all person ill with malaria shold have plasmodium in their blood"
EXPERIMENTS
- The next was to test the deduction through experiments which were designed as
- EXPERIMENTAL GROUP
- Blood of 100 malarial patients was examined under microscope
- CONTROL GROUP
- Blood of 100 healthy persons was also examined under microscope
RESULTS
- THE results of the experiments showed that almost all malarial patients had Plasmodium in their blood while 7 out of 100 healthy persons had plasmodium in their blood
- Now we know that plasmodium in the blood of healthy people was in incubation period.
- the results were quite convincing and proved that the hypothesis " plasmodium is the cause of malaria " was true.
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