Biological Method and Malarial Research
A Guide to Scientific Problem Solving in Biological Sciences
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Table of Contents
Q#1: What is the biological method? Discuss steps involved in the biological method.
Biological method:
The scientific method by which biological problems are solved is called the biological method.
Steps involved in biological method
Biology being a natural science follows the following steps of the scientific method to solve biological problems.
1. Recognition of the biological problem:
It begins with the information of a question relating to the problem. For example, what are the risk factors for heart failure? or what are the causes of lung cancer?
2. Making an observation:
The study of something with the naked eye or with the help of some instrument is called observation. Observations help scientists in finding a solution. For this purpose, they recall their old observations and also study previous research on the same problem.
Observations are of two types:
| Type of Observation | Definition | Examples |
|---|---|---|
| Qualitative observations | Observations that can be described but not measured. | Colour, taste, smell, texture, etc. |
| Quantitative observations | Observations that can be described numerically. | height, temperature, pressure, cost, length, etc. |
3. Formulate a Hypothesis
The untested explanation given by a scientist may be true or false and is called a hypothesis. The accuracy of the hypothesis can be tested through experiments. The hypothesis is a possible answer to a biological problem.
Characteristics of a good hypothesis:
- It should be based upon the observations of biologists.
- It is a proposed statement to answer the questions.
- It should be testable through experiments.
- It may be accepted or disprove after experimentation.
5. Deduction:
A deduction is a logical result of a hypothesis. It involves an ‘if’ and ‘then’ statement. A deduction is done through reasoning.
6. Reasoning
The process of thinking about something to draw a conclusion is called reasoning. There are two types of reasoning:
6. Experiment
In order to prove whether the given statement is true or false experiments are conducted. If the hypothesis is made true it is accepted otherwise it is rejected. For this purpose, two groups are made:
- a. Experimental group: Patients (people under observation) belong to the experimental group.
- b. Control group: Healthy persons belong to the control group.
If the results of experiments do not support any hypothesis then new hypotheses are developed and tested.
7. Conclusion and reporting drawn through data:
During experiments, the scientists collect data. This data is analyzed to come to a satisfactory conclusion. Scientists publish their conclusion in the form of research articles.
Theoretical Framework
8. Theory:
When more research is carried out on a hypothesis and all the available evidence favour it, then it becomes a theory.
9. Scientific laws/Principles:
A statement of fact that can explain many natural phenomena and is fully supported by experiments and also universally accepted by scientists then it becomes law or principle.
Q#2: Explain how biologists use scientific methods to solve the mysteries of addressing the malarial problem.
Malaria:
Malaria is the combination of two Italian words ‘mala means bad’ and ‘aria means air’. It is an infectious disease spread through the bite of female Anopheles mosquitoes. Malaria is a biological problem and so can be solved by steps of biological method.
1. Observation
Following are some observations made by scientists about malaria:
- Patients of malaria experience recurring attacks of chills and fever.
- People living in low-marshy areas are more affected by malaria.
- Drinking marshes water does not develop malaria.
2. Hypothesis and deduction
Different scientists formulated a different hypothesis to solve the malarial problem:
Hypothesis-I: “Plasmodium is the cause of malaria” (Based on Laveran).
Hypothesis-II: “Mosquitoes are involved in the spread of malaria” (Based on A.F.A King).
Hypothesis-III: “If mosquitoes are involved in the spread of malaria, then it must have plasmodium in its blood after it had bitten a malarial patient” (Based on Ronald Ross).
3. Deduction: On the basis of these observations, biologists made a deduction that “if plasmodium is the cause of malaria, then all the malarial patients should have plasmodium in their blood”
4. Experiments & 5. Results
Biologists examined the blood of several malarial patients (experimental group) and healthy persons (control group) under a microscope. It was observed that all the malarial patients had plasmodium in their blood while healthy persons were free from plasmodium. From these results, it was confirmed that “plasmodium is the cause of malaria”.
Q#3: Explain the biological problem “How is plasmodium transmitted to human beings?”
i. Observation
In 1883, A.F.A King listed 20 more observations about malaria, including:
- People who slept in open places suffered more from malaria than those who slept indoors.
- Less number of people suffered from malaria who used to sleep in smoking places.
- People who used mosquito nets suffered less than the ones who did not use mosquito nets.
ii. Hypothesis and deduction
A.F.A King suggested a hypothesis that “mosquito transmit plasmodium”. This led to the deduction that “if mosquitoes transmit plasmodium, then plasmodium should be present in mosquitoes”.
iii. Experiment and result
The Ronald Ross Experiment:
A British army physician, Ronald Ross, performed an experiment (for which he was awarded the Nobel prize) using Culex and Anopheles mosquitoes.
He let mosquitoes suck the blood of malarial patients (experimental group) and then bite healthy sparrows (control group). Culex caused malaria in sparrows while female anopheles mosquitoes caused malaria in human beings. Plasmodium was found first in the stomach wall of mosquitoes and later on in salivary glands.
iv. Result
Ronald Ross, on the basis on his experiment, confirmed the hypothesis and deduction of A.F.A King.
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