Nature and meaning of science

Correct answer: B. When it can be tested by observation or experiment

A good scientific question can be tested through observation or experiment. Identify testable questions in exams.

Correct answer: A. Consistency of the result

Repeatedly obtaining the same result indicates consistency and reliability. Link similar results with repetition.

Correct answer: A. A fact is supported by evidence

The direct answer is option A: a scientific fact is supported by evidence. In science, a fact is a statement strongly supported by repeatable observations, measurements, or other reliable evidence. A personal opinion is what someone thinks, likes, or believes; it may be sensible, but it is not scientific fact merely because a person says it. Option A is correct because evidence gives a claim a basis that others can examine and check. Option B is wrong because an opinion is not always experimentally proven; it may be a preference or judgement. Option C is wrong because a well-supported fact does not change simply with each person’s preference, although scientific knowledge can be refined when better evidence appears. Option D is wrong because facts and opinions do not have the same basis. For example, “water boiled at this measured temperature under these conditions” can be checked, while “this experiment was interesting” is an opinion. Exam cue: ask, “What observation or evidence supports this statement?”

Correct answer: A. Dissolve equal amounts of sugar at two different temperatures

Only temperature should be changed while other conditions remain the same. Identify a fair test in exams.

Correct answer: A. Recorded data obtained from an experiment

Recorded data obtained from an experiment are scientific evidence. Give priority to measured data in exams.

Correct answer: A. It can reveal weaknesses in the method and suggest improvements

A failed experiment reveals errors and the need for improvement. Treat failure as an opportunity to learn.

Correct answer: A. A hypothesis is an initial testable idea while a conclusion is based on results

A hypothesis is formed before testing while a conclusion is drawn after results. Remember the sequence in exams.

Correct answer: A. Scientific honesty

Publishing correct data is an example of scientific honesty. Identify unbiased reporting in exams.

Correct answer: A. Observation is directly obtained information while inference is its interpretation

Observation comes from senses or instruments while inference is drawn from that information. Understand the distinction in exams.

Correct answer: A. The plant is sad

Drooping leaves are an observation while calling the plant sad is an inference. Identify interpretative statements as inferences.

Correct answer: A. To make comparison and analysis easier

Tabulation means arranging observations or measurements in rows and columns. A table gives each value a clear place and often labels the quantities, units, and conditions. This organisation makes it easier to see patterns, compare groups, identify unusually high or low results, and use the data for later calculations or graphs. A table does not hide data, change values, or automatically end an experiment. It is a way of presenting information clearly.

Suppose temperatures are recorded for several days. Putting the day and temperature in separate columns allows direct comparison between days. Similarly, results from two conditions can be placed in adjacent columns so their differences are easy to inspect. Therefore, option A is correct because tabulation makes comparison and analysis easier. The other choices confuse data organisation with dishonest manipulation or with stopping the investigation.

Correct answer: A. To show relationships between variables

A graph clearly shows patterns in data and relationships between variables. Link graphs with identifying trends.

Correct answer: A. Thermometer

A thermometer is used to measure temperature. Match physical quantities with correct instruments in exams.

Correct answer: A. Stopwatch

A stopwatch is the most suitable instrument for measuring elapsed time or a time interval in an experiment. A thermometer measures temperature, whereas a metre scale is used to measure length. Exam tip: remember each instrument by matching it with the physical quantity it measures.

Correct answer: A. It is more accurate and verifiable

A measured value is obtained with a suitable instrument and can be verified. Treat measurement as more reliable than estimation.

Correct answer: A. Question hypothesis testing results conclusion

Scientific investigation begins with a question and proceeds through testing to a conclusion. Remember the logical sequence.

Correct answer: A. Extraneous variable

An extraneous variable can affect the result and should be controlled. Identify such factors for a fair test.

Correct answer: A. Controlled variables

Keeping controlled variables the same allows the effect of the independent variable to be observed. Identify constant factors.

Correct answer: A. Height of the plants

A dependent variable is the outcome that is measured or observed in an experiment. Here, the student measures the height of the plants, so plant height is the dependent variable. The type of soil is the independent variable being changed, while factors such as water and light should be kept the same. Exam tip: the quantity measured as the result is usually the dependent variable.

Correct answer: A. Type of soil

The direct answer is A: type of soil. The independent variable is the factor that the investigator deliberately changes to study its effect. Here, the student grows plants in different soils, so soil type is the planned difference. The plant’s growth may then be compared while other conditions, such as plant kind, water, light, and time, are kept as similar as possible. Option A is correct because it is changed by the student. Option B, plant height, is usually a dependent variable: it is measured as a possible result of the soil. Option C, number of leaves, is also a possible measured result, so it is another dependent variable, not the deliberately changed factor. Option D, time of measurement, is a condition or procedure detail; unless the investigation specifically changes time as the tested factor, it is not the independent variable in this question. The key chain is: change one factor, observe the response, and record the response. Memory cue: independent means “I change it”; dependent means “the result depends on it.”

Correct answer: A. Being willing to change ideas when new evidence appears

Open-mindedness means being ready to revise ideas based on new evidence. Link it with a scientific attitude.

Correct answer: A. Under the same conditions conclusions can apply everywhere

Scientific conclusions are independent of place and person under the same conditions. Link universality with identical conditions.

Correct answer: A. Examine its evidence and testing

A scientific idea should be accepted on the basis of evidence and testing. Value evidence more than reputation.

Correct answer: A. Confirmation bias

Selecting only supportive data is confirmation bias. Treat unbiased examination of all data as correct.

Correct answer: A. Controlled testing and sufficient evidence

Controlled testing and sufficient evidence are needed to establish causation. Do not confuse correlation with causation.