Biology For Class IX - Chapter No.2 - Solving A Biological Problem - Review Questions From Text Book & Short Questions

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CHAPTER 8
SOLVING A BIOLOGICAL PROBLEM

Review Questions From Text Book

1. Encircle the correct answer:
(i) Select the correct sequence of biological method.
(a) Law → Theory → Reasoning → Hypothesis
(b) Hypothesis → Theory → Law → Reasoning
(c) Hypothesis → Reasoning → Theory → Law ✔
(d) Law → Hypothesis → Reasoning → Theory

(ii) Select the odd one:
(a) Theory
(b) Law
(c) Hypothesis
(d) Ratio ✔

(iii) Field of research that examines mathematical representations of biological system called:
(a) Ratio
(b) Mathematical biology ✔
(c) Proportion
(d) Law

(iv) Biological method involves all of the following except:
(a) Data collection
(b) Observation
(c) Experiment
(d) Proportion ✔

(v) Scientific reasoning moves from specific to general:
(a) Inductive ✔
(b) Deductive
(c) Observation
(d) Both a and b

(vi) Quantitative observation is the use of:
(a) Senses
(b) Equipment ✔
(c) Guess
(d) Ratio

(vii) Equation stating that two ratios are equal:
(a) Ratio
(b) Proportion ✔
(c) Guess
(d) Senses

(viii) The comparison of two values is called:
(a) Ratio ✔
(b) Proportion
(c) Graph
(d) Table

(ix) What is a hypothesis?
(a) The same thing as an unproven theory.
(b) A tentative explanation that can be tested and is falsified. ✔
(c) A verifiable observation.
(d) A fact based on quantitative data that is falsified.

(x) In data organization, which method is mostly useful?
(a) Table
(b) Graph
(c) Ratio
(d) Both a and b ✔

2. Fill in the blanks:
(i) Problem solving approach of biology and other sciences called scientific method.
(ii) Solution of biological problem starts with observation.
(iii) The key component of the scientific process is hypothesis.
(iv) Scientific reasoning based on “if-then” statement called deductive reasoning
(v) Final step of the scientific method is developing conclusion.
(vi) The uniform or constant fact of nature, virtually an irrefutable theory is scientific law.
(vii) Once you have the data, you may need to perform mathematical analysis.
(viii) The equation stating that two ratios are equal is called proportions.
(ix) Ratio is comparison of two values.
(x) The cause of malaria is plasmodium.

3. Define the following terms:
(i) Ratio (ii) Biological method (iii) Graph (iv) Hypothesis (v) Law (vi) Inductive reasoning (vii) Conclusion (viii) Proportion (ix) Observation (x) Mathematical models
Ans: (I) RATIO:
Ratio is a comparison of two values expressed as a quotient (1st/2nd).
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.

(II) BIOLOGICAL METHOD:
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 the step-wise process in which a scientist finds out the reason of any biological problem about living things.

(III) GRAPH:
A graph can be defined as a pictorial representation or diagram that represents data or values in an organized manner. The points on the graph often represent the relationship between two or more things.
For data organization we will prepare a table or graph of the data. Graphing is an important procedure or mathematical representation used by scientists to display the data that is collected during a controlled experiment. The most common types of graph used in biology are bar graphs, circle graphs, and line graphs.

(IV) 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”. Hypothesis must either be supported or falsified by experiment."

OR

"A hypothesis is an idea that is suggested as an explanation for a natural event, particular experience, or specific condition that can be tested through definable experimentation."
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.

(V) LAW:
"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.

(VI) INDUCTIVE REASONING:
After collecting information about the problem and formulate the hypothesis, if the reasoning process moves from specific to general than it is called inductive reasoning.
For example: Shark is a fish. All fishes have scales therefore sharks also have scales.

(VII) CONCLUSION:
The final step of the biological 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, repeat the experiment or think of other ways to improve our procedure.
Example: Conclusion is made that “Plasmodium is the cause of malaria”.

(VIII) PROPORTION:
Proportion is the statistical methods apply in data analysis. A Proportion is an equation stating that two ratios are equal.
Example: 4:12::1:3.

(IX) OBSERVATION:
The first step of biological method 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.
"An observation is a statement of knowledge gained through the senses (qualitative) or through the use of scientific equipment (quantitative)."
Observation can be made on anything from plant movement to animal behavior.
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.

(X) MATHEMATICAL MODELS:
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.


4. Distinguish between the following in tabulated form:
(i) Theory and Law
(ii) Inductive reasoning and deductive reasoning
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”

5. Write short answers of following questions:
(i) Theory is highly reliable scientific explanations, why?
Ans: 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 explanations of natural phenomena. They unify or verify multiple times by many repeated observations and data collected from lots of experiments that confirms them as valid. A theory is valid as long as there is not a significant amount of valid evidence to dispute it.

(ii) Why biological sciences need mathematical models?
Ans: Mathematical biology is a field of research that examines mathematical representations of biological systems. Key role of mathematics in biology is the creation of mathematical models. These 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 is an integral part of the scientific process, which plays a critical role in better understanding the natural world.

(iii) Draw a chart showing steps involved in biological methods.
Ans: Chart Showing Steps Invilveb In Biological Method:

(iv) Why table or graph is necessary for data organization?
Ans: Table or graph is necessary for data organization because data tables and graphs are usually used to organize the information to show patterns and relationships. It also give visual image of the observations, simplifies data and help in making valid conclusion. Before conducting a meaningful investigation. It's important to organize the data we collected. By organizing data, a scientist can more easily interpret what has been observed.

OR

Table and graph is necessary for visual representation of results. Before conducting a meaningful investigation, it's important to organize the data we collected. By organizing data, scientist can more easily interpret what has been observed. Since most of the data scientist collect is quantitative, data tables and charts are usually used to organize the information.

(v) Why experiment is necessary for theory?
Ans: Experiment Is Necessary For Theory:
Experiment is necessary for theory because experiments play important role in science. One of its important role is to test theories and provide the basis for scientific knowledge. 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.
Thus 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. If hypothesis was supported, its great. If not, repeat the experiment to improve the procedure. Incorrect hypothesis is rejected and those experiments shows same results of hypothesis repeatedly are accepted. The correct results leads to give a theory.

OR

Natural science is a reasonable enterprise based on valid experimental evidence, criticism, and rational discussion. It provides us with knowledge of the natural world, and it is experiment that provides the evidence that grounds this knowledge. Experiment plays many roles in science. One of its important roles is to test theories and to provide the basis for scientific knowledge. It can also call for a new theory, either by showing that an accepted theory is incorrect, or by exhibiting a new phenomenon that is in need of explanation.
Experiment can provide hints toward the structure or mathematical form of a theory and it can provide evidence for the existence of the entities involved in our theories. Finally, it may also have a life of its own, independent of theory. Scientists may investigate a phenomenon just because it looks interesting. Such experiments may provide evidence for a future theory to explain.

OR

Experiment can provide hints toward the structure or mathematical form of a theory and it can provide evidence for the existence of the entities involved in our theories. Finally, it may also have a life of its own, independent of theory. Scientists may investigate a phenomenon just because it looks interesting. Such experiments may provide evidence for a future theory to explain.

MORE SHORT QUESTIONS

Q.1: Define the following terms:

• Deductive reasoning
• Mathematical Biology
• Science
• Scientific method
• Theory
• Principle

1. DEDUCTIVE REASONING:
After collecting information about the problem and formulate the hypothesis, if the reasoning process moves from general to specific than it is called deductive reasoning. It is a logical prediction. 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.”

2. MATHEMATICAL BIOLOGY:
Mathematical biology is a field of research that examines mathematical representations of biological systems.

3. 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.

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

5. 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.

6. 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.2: Mention or name the steps of biological methods?
Ans: Steps Of Biological Method:

• Observation
• Hypothesis
• Reasoning
• Experiment
• Result
• Conclusion
• Theory