Biology 9 - Ch.2 Solving Biology Problem

Biology Punjab Text Book 2020 Notes for the students of the ninth class. Learn these notes and enhance you grade in final exams.

Biology 9 - Ch.2 Solving Biology Problem

Ch.2 Solving Biology Problem

Dear Students before you start learning these questions, DivSols recommend you understand the important terminologies first for better understanding. Click here to learn about the important terms.

Short and Long Questions

Q#1 Define science.

Ans: Science is a systemized knowledge derived from observation and experiments carried out to determine the principles of how nature operates.

Q#2: ''Man has always been a biologist''. Justify the statement.

Ans: Man has always been a biologist. He has to be a biologist in order to live. Early, in history, he was a hunter of animals and a gathered of fruits, seeds, roots, etc. The more he knew about their habitat the more successful hunter he was. The more he knew about plants the better he distinguished between edible and non. edible plants.

Q#3: What is the biological method? Give its significance also.

Ans: The scientific methods in which biological problems are solved. is termed as a biological method. It comprises of the steps a biologist adopts in order to solve a biological problem.

Significance of biological method:

The biological method has played an instrumental part in biological research for almost 500 years. From Galileo's experiment back in the 1590s to current research the biological method has contributed to the creation of vaccines and advancements in medicine and technology. The biological method also ensures the quality of data for public use.

Q#4 Describe the steps involved in solving a biological problem by a biologist?

Ans: solving a Biological problem:

  1. Recognition of the biological problem
  2. observations
  3. Hypothesis formulations
  4. deductions
  5. Experimentation
  6. Summarization of results (creates tablets, graphic, etc)
  7. Reporting the results

(1) Recognition of a biological problem:

Biologists go for adopting biological methods when they encounter some biological problems. A biological problem is a query that is either asked by someone or comes in the biologist's mind by himself.

(2) Observation

As the first step in solving a biological problem, the biologist recalls his/her previous observation ar make new ones. Observation is made with 5 senses of vision. hearing, smell, taste, and touch.

types of observation:

Observation may be both qualitative and quantitative. Quantitative observations are considered more accurate than qualitative ones because the former are invariable and can be recorded in terms of numbers. Examples of qualitative  and quantitative observations are given below:

Qualitative Observations Quantitative Observations
1. The freezing point of water is colder than the boiling point. 1. The freezing point of water is 00C and boiling point is 1000C
2. A liter of water is heavier than a liter of ethanol. 2. A liter of water weighs 1000 grams and a liter of Ethanol weighs 789 grams

Note: Observations also include reading and studying what others have done in the past because scientific knowledge is ever-growing.

(3) construction and formulation of Hypothesis:

The tentative explanation of observations is called a hypothesis. It may be defined as a proposition that might be true.

Characteristics of Hypothesis:

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 the available observation
  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 disapprove the hypothesis.

Conditions for Hypothesis:

A great deal of creative and careful thinking is necessary for the construction of a hypothesis. Biologists use reasoning to formulate a hypothesis.

Type of Reasoning

The reasoning may be of two types.

(1) Inductive Reasoning:

In inductive reasoning, specific observations are used to draw the general hypothesis. For Example,  observed cells in x, y, and z organisms therefore all organisms have cells.

(2) Deductive reasoning:

Deductive reasoning flows from general to specific. From general observation, a biologist conducts a specific hypothesis. For Example: If all organisms have cells and humans are organisms, then humans should have cells.

  1. Deduction

The biologists draw dedications from the hypothesis. dedications are also drawn inductive and deductive reasoning. Generally, in a biological method, If a particular hypothesis is true then one should expect a creation result. This involves the use of ''If-then'' logic.

  1. Experimentation:

Most basic steps of biological methods biologists perform experiments to see if the hypothesis is true. An experiment involves an alternative hypothesis. A successful experiment is that which demonstrates one or more alternative hypotheses as incorrect ( inconsistent with experimental and observation results). The incorrect hypothesis id rejected and those which prove consist of experimental results are accepted. An expected hypothesis needs to be valid and useful. It makes further predictions that provide an important way to further test its validity.

  1. summarization of results:

The biologists gather actual, quantitative data from experiments. Data for each of the groups are then averaged and compared statistically. To draw conclusions the biologists also use statistical analysis.

  1. reporting the results:

Biologist publishes their writings in scientific journals and books, in talks in international seminars and meeting and in seminars of colleges and universities. Publishing results is an essential part of the scientific method. It allows other people to verify the results or apply the knowledge to solve other problems.

Q#5: How scientists contrast an ''experimental group'' with a ''control group''?

Ans: In science, when doing the experiment. It must be a controlled experiment. The scientists must contrast an '' experimental group'' With a ''control group''. The two groups are treated exactly alike except for one variable being tested.

For example. In an experiment to check the necessity of CO2 for photosynthesis one can contrast the control group ( Plant with freely available carbon)dioxide) with an experimental group ( a plant with no available carbon dioxide). The necessity of carbon dioxide would be proved when photosynthesis occurs in the control group and doesn't occur in the experimental group.

Q#6: What is the observation of Darwin?

Ans: Darwin not only took notes during his voyage but he also reads the work of other naturalists to form his history of evaluation.

Q#7: Let's consider a hypothesis.'' All plant cells have a nucleus''. Write the deduction made by the biologists about this hypothesis?

Ans: Biologists can't usually check every situation where a hypothesis might apply. Let's consider a hypothesis. ''all plant cells have nucleus''. Biologists can't examine every living plant that has ever lived to see if the hypothesis is false. instead. biologists generate a deduction: ''If I example cells from a blade of grass than each one will have a nucleus''.

Q#8: Which one is an effective remedy for malaria?

Ans: In fact, quinine was the only effective remedy for malaria from the 17th to 20th centuries.

Q#9: Describe the steps involved in the biological method taking malaria as an example.

ANS: See Q#1 from exercise (Understanding the concept)

Q#10: Why female mosquitoes need the blood of mammals or birds?

Ans: Female mosquitoes need the blood of mammals and birds for the maturation of their eggs.

Q#11: Describe the function of saliva in female mosquitos.

Ans: When a female mosquito pierces the skin with her mouthparts, she injects a small amount of saliva into the wounds before drawing blood. The saliva prevents the blood from clotting in her food canal.

Q#12: How welts appear After the mosquito leaves?

Ans: The welts appear after the mosquito leaves is not a reaction to the wound but an allergic reaction to the saliva. In most cases, the itching sensation and swelling subside within several hours.

Q#13 While testing the hypothesis that plasmodium in the cause of malaria.  what would be the control group of the experiment? Blood of material patients or blood of healthy patients?

Ans: Blood of healthy persons.

Q#14: How theory, Law, and principle are formulated?

Ans: THe hypothesis that stands the test of time (Often tested and never rejected) are called theories. A theory is supported by a great deal of evidence. Protective theory keeps on suggesting new hypotheses and so testing goes on. Many biologists take it as a challenge and expert greater effort to disapprove of the theory.

law and principle

If a theory survives such a doubtful approach and continues to be supported by experimental evidence. It becomes a law of a principle. A scientific law is a uniform or constant fact of nature. It is an irrefutable theory. The example of biological theory or Hardy-Weinberg law and Mendel's law of inheritance.

Q#15:Define Data?

Ans: Data can be defined as a single piece of information such as names, dates, and values made from observation and experimentation.

Q#16: How the principles of ratio and proportion are used in biological methods?

Ans: see Q#3 from exercise(understanding the concept.)

Q#17: Briefly describe data organization and data analysis are important steps in the biological method

Ans:      Data organization

  1. in order to formulate and then to test the hypothesis, scientists collect and organize data. through the use of variable and control results can be determined. Variables are those factors being tested in an experiment and are usually compared to a control. A control is a known measure to which scientists can compare their results.
  2. Prior to conducting an experiment, It is very important for scientists to describe data collection methods. It ensures the quality of the experiment. Attention must be paid to ensure the data collection methods are kept the balance.
  3. Data is organized in different formes like graphics, tables, flow charts, maps, and diagrams.

Data analysis 

Data analysis is necessary to prove or disapprove a hypothesis by experimentation. The methods involved in testing/analyzing the data are also important since an experiment is repeated by others to ensure the quality of results. Depending on the type of data the biological problem, this might include the application of statistical methods. i.e.ratio and proportion. when a relation between two numbers e.g.' a' and 'b' is expressed in teams of the quotient (a/b) SUCH A RELATION is a ratio of one number to the other. A ratio may be expressed by putting a division (+) or colon(:) between two numbers. For example. The ratio between 50 material patients and 150 manal persons is 1:3.

Q#18: Justify mathematics as an integral part of the scientific process.

Ans: See Q#4 from exercise (understanding the concept)