Malaria is a common disease in many countries including Pakistan. You will know how biologists solved the biological problem concerning malaria.
In human history, malaria has killed more people than any other disease.
Biological Problem 1: What is the cause of malaria?
1. Observations
This disease was known to physicians of the ancient times (more than 2000 years ago). In the last part of 19th century, there were four major observations about malaria.
Quinine was the only remedy for malaria from the 17th to the 20th century.
Malaria and marshy areas have some relation. Quinine is an effective drug for treating malaria. Drinking the water of marshy areas does not cause malaria.
In 1878, a French army physician Laveran did research on the "cause of malaria". He took the blood from a malarial patient and examined it under microscope. He noticed some microorganisms in the blood. The microorganism was given a name - Plasmodium.
2. Hypothesis
Biologists thought on these observations and discoveries and developed a hypothesis i.e. "Plasmodium is the cause of malaria"
3. Deduction
They developed a logical result (deduction) by taking this hypothesis as true. The deduction was; "If Plasmodium is the cause of malaria, then all malarial patients should have Plasmodium in their blood."
3. Experiment and Results
In order to test the deduction, biologists performed experiments. They examined the blood samples of 100 malarial patients and 100 healthy persons under microscope. The following was the result of these experiments;
In these experiments, the malarial patients were the experimental group while the healthy persons were the control group.
Most of the malarial patients had Plasmodium in their blood.
The result proved that the hypothesis "Plasmodium is the cause of malaria" was true.
Biological Problem 2: How Plasmodium gets into the blood of man?
The next biological problem was to learn about "how Plasmodium gets into the blood of man". Biologists were having following observations;