Biology For Class IX - Chapter No.2 - Solving A Biological Problem - Questions and Answers

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CHAPTER 2
SOLVING A BIOLOGICAL PROBLEM

Questions and Answers

Q.1: What is science and scientific method?
Ans: SCIENCE:
Science is the systematic study of nature and how it affects us and the environment. It is a body of knowledge that is constantly changing through the use of better and more accurate tools for investigation.

SCIENTIFIC METHOD:
At the core of biology and other sciences lies a problem-solving approach called the scientific method. The scientific method is a series of steps followed by scientific investigators to answer specific questions about the natural world.

Q.2: (a) Define Biological method and biological problems?
Ans (a): BIOLOGICAL METHOD:
Biology is the branch of science concerned with the study of living things, or organisms. The system of advancing knowledge by formulating a question, collecting data about it through observation and experiment, and testing a hypothetical answer about living things is called biological method.

OR

A biological method is a scientific method used to solve biological problems which is related to or produced by a living organism.

BIOLOGICAL PROBLEM:
Biological problem is a set of questions to be solved, about the natural world. These problems can be environmental, ecological, health related, etc.
Example: Disease Malaria (the greatest killer disease of man for centuries) which spread through a female Anopheles mosquito. Previously the cause of malaria was unknown. It was thought that the malaria is caused by “bad air” (Latin word: 'mala' means bad, and 'aria' means air). This problem is solved when a Scientist identified the reason of malaria.

Q.3: Draw a chart showing steps involved in biological methods and describe each step briefly? OR Explain the steps of biological methods in details? OR How biological method is used to solve biological problems? OR Describe biological method Used to solve the problem of Malaria
Ans: STEPS SHOWING BIOLOGICAL METHOD
Biological method is consist of following step-wise process.

1. Observation OR Related observations and previous knowledge (Data collection)
2. Hypothesis
3. Reasoning To explain
   a) Inductive Reasoning
   b) Deductive Reasoning
4. Experiment
5. Result
6. Conclusion
7. Theory

In order to resolve specific biological problem, a same biological method (problem-solving) is adopted by scientists to find answers that are logical and supported by evidence.
1. OBSERVATION:
The first step is to identify the reason of the problem followed by the formulation of a question about what has been observed. The solution of biological problem starts with observation. Observation can be made on anything from plant movement to animal behavior. Thus

"An observation is a statement of knowledge gained through the senses (qualitative) or through the use of scientific equipment (quantitative)."

For Example:
In 1880, a French physician, Laveran, studied the blood sample of malaria patient under microscope and observed tiny creatures in it and named as Plasmodium.

"So the observation was made that Plasmodium is present in the blood of malaria patients."

2. HYPOTHESIS:
Hypothesis is a key component of the scientific process. It is defined as:

“The intelligent guess made by a scientist in the form of statement”.
OR
To solve a scientific problem, one or more intelligent guess are made on the basis of the observations. Such intelligent guess is called a Hypothesis.

A hypothesis must be testable by scientific method. That means, We should be able to test our hypothesis through experimentation. Hypothesis must either be supported or falsified by experiment.
For Example:
In malaria case, an intelligent guess is made after observation that "Plasmodium is the cause of malaria." But it is only a guess which can be presented as a hypothesis.

3. REASONING:
Biologists collect information about the problem and formulate the hypothesis by using a reasoning process i.e.

1. Inductive reasoning and
2. Deductive reasoning.

a) Inductive reasoning: moves from specific to general
e.g. Shark is a fish. All fishes have scales therefore sharks also have scales.

b) Deductive reasoning: moves from general to specific. It is based on “if then” statement. Deductive reasoning can be tested and verified by experiments. For Example:
In malaria case, the following deduction is made:

“If Plasmodium is the cause of malaria, then all the malaria patient should have Plasmodium in their blood”

4. EXPERIMENT:
Once a problem has been observed and a hypothesis is suggested, the next step in the scientific method is to design an experiment based on reasoning.

"Experiment is a practical performance of a scientist to identify the real cause of a problem based on inductive and or deductive reasoning."

A key assumption is that the experiment will be repeated many times by other scientists. Scientist performs two types of test i.e.

1. Control Group: Group of unaffected people or healthy people.
2. Experimental Group: Group of affected people like malaria people

For Example:
To find out the cause of malaria, blood samples of 100 malaria patients (experimental group) and the blood samples of 100 healthy persons (control group) were examined under microscope.

5. RESULTS:
The results are where we report what happened in the experiment. That includes detailing all observations and data made during experiment.

"Result verifies the hypothesis."

For Example:
In the case of malaria, it was found that all the malaria patients (experimental group) had Plasmodium in their blood whereas the blood samples of healthy persons (control group) were free from Plasmodium.

6. CONCLUSION:
The final step of the scientific method is developing conclusion. This is where all the results from the experiment are analyzed and a determination is reached about the hypothesis. If hypothesis is supported, its great. If not, scientists repeat the experiment or think of other ways to improve our procedure.
For Example:
Conclusion is made that “Plasmodium is the cause of malaria”.

7. THEORY:
Scientific theories, are well-tested and highly reliable scientific explanations of natural phenomena.

"If hypothesis is proved to be correct, then scientists unify many repeated observations and data collected from lots of experiments and uniform results, then this hypothesis becomes a theory."

For example: Theory of Evolution.

Q.4: Define Theory and law and principle
Ans: THEORY:
As more and more evidence come to hand in the favour of hypothesis, the hypothesis gains increasing acceptance and eventually is promoted to the rank of a theory.

"A theory is a set of scientific consumptions consistent with one another and supported by evidence, but not fully proved. Scientific theories, are well-tested and highly reliable scientific explanations of natural phenomena. They unify many repeated observations and data collected from lots of experiments and uniform results, then this hypothesis becomes a theory."

For example: Theory of Evolution.

LAW:
If a theory survive such doubtful approach and continues to be supported by experimental evidence, it becomes a law. Thus:
"A scientific law is a uniform or constant fact of nature, it is virtually an irrefutable theory." Biology is short in laws due to puzzling nature of life.
For Example: Mendel'slaw of inheritance.

PRINCIPLE:
If a theory survive such doubtful approach and can explain many natural phenomena. It continues to be supported by experimental evidence and also universally accepted by the scientists it becomes a scientific principle.

Q.5: Distinguish between the following in tabulated form:
(i) Theory and Law
(ii) Inductive reasoning and deductive reasoning
(iii) Theory and Hypothesis
(iv) Qualitative and Quantitative Observation
Ans:(i) Distinguish or Difference between Theory and Law

S.NO.	Theories	Law
1.	If hypothesis is proved to be correct from repeated experiments, then it is called scientific theory	When a theory is again and again proved to be correct, then it is called a scientific law or principle.
2.	Scientific theories are well-tested and highly reliable scientific explanations of natural phenomena.	A scientific law is a uniform or constant fact of nature.
3.	A theory is the explanation of observation.	A law is an observation
4.	Theory explains why something happens	A law describes what happens when certain conditions are present.
5.	A theory can be revised or replaced by another better theory	A law cannot be replaced or changed.
6.	They unify many repeated observations and data collected from lots of experiments.	A law has no such requirements of experimentation.
7.	A theory may become obsolete with time.	A law does not become obsolete with time.
8.	A theory may be strong or weak according to the amount of evidence available.	A law is universally obserable fact.
9.	Example: Theory of Evolution, Cell theory	Example: Mendel's inheritance law, Law of dominance

(ii) Distinguish or Difference between Inductive reasoning and deductive reasoning

S.NO.	Inductive reasoning	Deductive reasoning
1.	Inductive reasoning moves from specific to general facts	A Deductive reasoning moves from general to specific facts.
2.	Inductive reasoning aims at developing a theory.	Deductive reasoning aims at testing an existing theory.
3.	Inductive argument can be strong or weak, which means conclusion may be false even if premises are true.	Deductive arguments can be valid or invalid, which means if premises are true, the conclusion must be true
4.	In inductive reasoning, the conclusions are probabilistic.	In deductive reasoning, the conclusions are certain
5.	It is based on observation.	It is based on “if - then” statement or theory.
6.	Inductive reasoning can not verified because it is obtained from hypothesis and may be false.	Deductive reasoning can be tested and verified by experiments.
7.	Inductive reasoning follows a borrom-up approach.	Deductive reasoning follows a top-down approach.
8.	Inductive reasoning starts from the conclusions.	Deductive reasoning starts from premises.
9.	Use of inductive reasoning is fast and easy, as we need evidence instead of true facts. We often use it in our daily life.	Use of deductive reasoning is difficult, as we need facts which must be true.
10.	e.g. Shark is a fish. All fishes have scales therefore sharks also have scales.	For Example: In malaria case, the following deduction is made: “If Plasmodium is the cause of malaria, then all the malaria patient should have Plasmodium in their blood”

(iii) Distinguish or Difference between Theory and Hypothesis

S.NO.	Theory	Hypothesis
1.	It is well-tested and highly reliable scientific explanation of natural phenomena.	It is an intelligent guess made by a scientist in the form of statement.
2.	A theory is a set of scientific assumptions consistent with one and other supported by evidence but not fully proved.	It may be a possible answer to a particular problem which is made by scientists on the basis of available data.
3.	It is tested and proven scientifically	It is not tested or proven scientifically
4.	The results are certain	The results are not certain
5.	e.g.: Malaria Theory, Theory of Evolution	e.g.: Plasmodium is the cause of Malaria.

(iv) Distinguish or Difference between Qualitative and Quantitative Observation

S.NO.	Qualitative Observation	Quantitative Observation
1.	It is an observation or a statement of knowledge gained through the five senses	It is an observation or a statement of knowledge gained through the use of scientific equipment.
2.	quantitative data is made with five senses of vision, hearing, smell, taste and touch.	Tools for qualitative data include measuring equipment, such as ruler, balance etc.
3.	It is considered as inaccurate	It is considered as accurate
4.	It can not be measure and recorded in terms of numbers.	It is measurable and can be recorded in terms of numbers
5.	Observations are based on characteristics	Observations are based on quantities.
6.	e.g.: The freezing point of water is colder than the boiling point	e.g.: The freezing point of water is 0°C and the boiling point is 100°C.

Q.6: Define data? Briefly describe data organization and data analysis? Also draw a bar chart and pie chart to explain data organization.
Ans: DATA:
Data can be defined as the information such as names, dates or values made from observations and experimentation.

DATA ORGANIZATION AND DATA ANALYSIS
Data organization and data analysis are important steps in biological method.

Data organization:

• For data organization, different formats like graphs, tables, flow charts, maps and diagrams of the data are prepared.
• All the data points, whether they are bad or do not support predictions are recorded. Some of the most incredible discoveries in science were made because the data looked wrong!
• Once the data is recorded, a mathematical analysis are performed to support or refuse hypothesis.

Data analysis:
Data analysis is necessary to prove or disprove a hypothesis by experimentation. In data analysis, the statistical methods (ratio and proportion) are applied.

• Ratio: is a comparison of two values expressed as a quotient (1st/2nd). It may be expressed by putting a division (/) or colon (:) mark between the two numbers.
  Example: A flower has 4 sepals and 12 petals. The ratio of sepals to petals is 4:12. This ratio can also be expressed as an equivalent fraction 1:3.
• Proportion: is an equation stating that two ratios are equal. Or It joins two equal ratios by the sign of equality (=).
  Example: 4:12 = 1:3 is a proportion between the two ratios. This proportion may also be expressed as 4:12::1:3.

A bar chart showing the trend of malaria cases reported in Sindh 2016-17

A Pie Chart showing Infectious diseases in Pakistan (2006) 

Q.7: Why Mathematics is an integral part of the scientific process?
Ans: Mathematics As an integral part of the scientific process:
Suppose, if a biologist studying the insect population. He goes into the field and count the population sample in a specific region, then compare sample with other regions to get population estimated. At every step of this process, he depends upon mathematics to measure, predict, and understand natural phenomena. Mathematical biology is a field of research that examines mathematical representations of biological systems. One key role of mathematics in biology is the creation of mathematical models. There are equations or formulas that can predict or describe natural occurrences, such as organism behavior patterns, population changes over time, structure of protein, height of living organisms, population of an endangered species, bacterial growth and so on. Finally we can say that mathematics plays a critical role in better understanding the natural world.