BIOLOGICAL METHODDS:
Knowledge of biology is not only a thought of a scientist. It is actually out come of observations, experiments and confirmation of the facts by many researchers.
Before a scientist says anything, he has to go through following procedures
Hypothesis: A hypothesis is a statement of scientist based on his observations. Hypothesis may or may not be correct. That is why it is tested on the basis of experiments.
Inductive Reasoning: It is a method in which scientist uses fact to reach a general conclusion. Inductive reasoning is mainly based on experiments, which may prove the hypothesis.
Deductive reasoning: Whenever an experiment is conducted, there are many ifs and buts. These kinds of things create a lot of fuss and confusion. It is therefore necessary for any scientist to check and re-check his hypothesis through repeated experiments. If the results of experiments are same, a theory is proposed. The theory may be again tested under different situations. If a theory is proved true under all circumstances, it than becomes a law.
MALARIA
Old Concept: Malaria is actually a fever during which, the patient fells chill. In old days, it was thought that malaria is caused due to bad air, that is why this name was fixed which means Mala= bad Aria=air. The hypothesis of ancient people was that Malaria is caused due to bad air.
New Concept: Laveron (1878) who was a doctor in French army rejected the old hypothesis. He prepared blood sides of healthy and malarial patients and found plasmodium parasites in the patients suffering from malaria. In 1897 Ronald Ross discovered plasmodium from the stomach of female Anopheles mosquito. These findings clearly indicated that Malaria is caused by Plasmodium parasite and is transmitted to humans through mosquitoes, which are vector of malaria.
The findings of Laveron have been tested many times and it has become a fact that malaria is caused by plasmodium parasite.
MALARIA FACT SHEET: Malaria is an infectious disease caused by a one-celled parasite known as Plasmodium. The parasite is transmitted to humans by the bite of the female Anopheles mosquito. The Plasmodium parasite spends its life cycle partly in humans and partly in mosquitoes. (A) Mosquito infected with the malaria parasite bites human, passing cells called sporozoites into the human’s bloodstream. (B) Sporozoites travel to the liver. Each sporozoite undergoes asexual reproduction, in which its nucleus splits to form two new cells, called merozoites. (C) Merozoites enter the bloodstream and infect red blood cells. (D) In red blood cells, merozoites grow and divide to produce more merozoites, eventually causing the red blood cells to rupture. Some of the newly released merozoites go on to infect other red blood cells. (E) Some merozoites develop into sex cells known as male and female gametocytes. (F) Another mosquito bites the infected human, ingesting the gametocytes. (G) In the mosquito’s stomach, the gametocytes mature. Male and female gametocytes undergo sexual reproduction, uniting to form a zygote. The zygote multiplies to form sporozoites, which travel to the mosquito’s salivary glands. (H) If this mosquito bites another human, the cycle begins again.
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