9th Class Biology Chapter 2 Notes
Important Notes of Chapter No.2: Solving A Biological
Problem or 9th class biology chapter 2 notes written by Honorable Sir Adnan Haider Suib. These notes are very helpful in the preparation of 9th class biology chapter 2 notes for students of the 9th class Biology Urdu Medium and these are according to the paper patterns of all Punjab boards.
Summary and Contents:
Topics which are discussed in the notes are given below:
- Very Important Multiple Choice Questions (MCQs) of Chapter No.2 Solving A Biological
Problem Urdu Medium
- Science is the systemized knowledge derived from observations and experiments. These experiments
are carried out to determine the principles about how nature operates. Scientists like chemists,
biologists and physicists use the same scientific method to make and test new theories.
In this chapter, we will study the steps of biological method. We will study malaria as an example
to understand the steps in detail.
- Biological Method: Questions about living things have provided problems that man has investigated to aid his own
survival and to satisfy his desire to know. The scientific method in which biological problems are
solved, is termed as biological method. It comprises the steps a biologist adopts in order to solve a
biological problem.
Biological method has played an important
part in scientific research for almost
500 years. From Galileo’s experiment
(in the 1590s) to current research, the
biological method has contributed to
the advancements in medicine, ecology,
technology etc. Biological method also
ensures the quality of data for public use.
- Biological problem, hypothesis, deductions and experiments: In biology (like other sciences), new things are being discovered and long-held theories are being
modified or replaced with better ones as more data/knowledge is accumulated. This happens when
biologists recognize some biological problem and go for its solution. In solving a biological problem,
biologist takes following steps;
- Recognition of biological problem
- Observations
- Hypothesis formulation
- Deductions
- Experimentation
- Summarization of results (create tables, graphics etc)
- Reporting the results
- 1. Recognition of the Biological Problem: Biologists go for adopting biological method when they encounter some biological problem. A
biological problem is a question related to living organisms that is either asked by some one or
comes in biologist’s mind by himself.
- 2. Observations: As the first step in solving a biological problem, biologist recalls his/her previous observations or
makes new ones. Observations are made with five senses of vision, hearing, smell, taste and touch.
Observations may be both qualitative and quantitative. Quantitative observations are considered
more accurate than qualitative ones because the former are invariable and measurable and can
be recorded in terms of numbers. Examples of qualitative and quantitative observations are given
below. Observations also include reading and studying what others have done in the past because
scientific knowledge is ever-growing.
- Qualitative observations:
- The freezing point of water is colder than
the boiling point. A liter of water is heavier than a liter of
ethanol.
- Quantitative observations:
- The freezing point of water 0°C and the
boiling point is 100°C. A liter of water weighs 1000 grams and a liter
of ethanol weighs 789 grams.
- 3. Formulation of Hypotheses: Observations do not become scientific observations until they are organized and related to a
question. Biologist organizes his/her and others’ observations into data form and constructs a
statement that may prove to be the answer of the biological problem under study. This tentative
explanation of observations is called a hypothesis. It may be defined as a proposition that might be
true. A hypothesis should have the following characteristics:
-
1. It should be a general statement.
2. It should be a tentative idea.
3. It should agree with available observations.
4. It should be kept as simple as possible.
5. It should be testable and potentially falsifiable.
- In other words, there should be a way to show
the hypothesis is false; a way to disprove the hypothesis.
A great deal of careful and creative thinking is necessary for the formulation of a hypothesis.
Biologists use reasoning to formulate a hypothesis.