UNIT: 02 Solving a Biological Problem

 

BIOLOGY CLASS: IX

 

SHORT QUESTIONS

 

Q1. Define Biological method.

Ans: 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..

 

Q2.Define Hypothesis.

Ans. 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.

Q3. Why experiment is necessary for theory?

Ans. All the theory is based on many repeated observations and data collected that is only obtained by performing repeated experiments

Q.4 Write difference between Qualitative and Quantitative data.

Ans: Quantitatives: Data refers to measurable observations. Tools for quantitative data include.

Qualitatives: Data refers to observations using five senses.

DETAIL QUESTION ANSWER:

 

Q1.Describe biological method with different steps.

Ans(i)Observation: The first step of biological problem starts with observation. 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 it.

(ii)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". 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.

(iii) Reasoning: Biologists collect information about the problem and formulate the hypothesis by using a reasoning process i.e. inductive reasoning and deductive reasoning.

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

Deductive reasoning: moves from general to specific. It is based on "if then statement. Deductive reasoning can be tested and verified by experiments 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.

 

(iv) Experiment; Experiment is a practical performance of a scientist to identify the real cause of a problem. Scientist performs two types of experiments i.e. control group and experimental group.

Experimental group: In this group blood sample of 100 malaria patients is tested.

Control group: In this group bloodsamplesof 100 healthy persons (were examined under microscope).

(v) Result: On the basis of experiment result is obtained, which helps in conclusion and to make theory.

(vi) Conclusion: On the basis of experiments, observations, and new data collection conclusion are drawn.

(vii): Theory is a well-tested and highly reliable scientific explanation of natural phenomena. They unify many repeated observations and data collected from lots of experiments. For example theory of evolution.

(Viii) Law and principle: When theory is accepted and proved true ,then it is considered as a general principle i.e. Law.