Scientific questions and observations

Temperature measurement is based on a standard instrument and numerical value. Distinguish subjective from objective statements.

Focusing on one main factor allows its effect to be tested clearly. Identify focused questions.

This question investigates a measurable relationship between light and flower opening. Form testable questions from observations.

Immediate recording reduces memory-related error. Treat note-taking during observation as correct practice.

A colour chart improves consistency among different observers. Understand the benefit of standard references.

To determine the effect of light it should be changed while other factors remain constant. Choose experiments for causal questions.

Parallax error occurs when a scale is viewed from an angle instead of from the correct position. In a liquid container, the apparent position of the meniscus can shift when the eye is above or below the liquid level. The observer may then record a value that is higher or lower than the actual volume, even though the instrument itself has not changed. To reduce this error, place the eye at the same height as the meniscus and read the appropriate part of the curve according to the liquid being measured.

Here, the student viewed the liquid from above eye level, so the line of sight was not perpendicular to the scale. That can produce a reading error due to viewing angle. Therefore, option A, parallax error, is correct. Selection bias concerns how subjects are chosen, publication bias concerns which results are reported, and sampling error concerns variation from studying part of a population; none describes this scale-reading problem.

Measuring sound level with an instrument makes the observation quantitative and comparable. Choose suitable measurement methods.

Repeated similar observations increase reliability but do not give absolute certainty. Understand repetition.

A scientific question should be studied using responsible and safe methods. Recognise ethics in studies involving organisms and people.

Selecting only clear days may create weather-related bias. Examine representativeness of observational sampling.

An unclear operational definition makes comparison and repetition difficult. Look for measurable criteria.

A fair comparison requires important conditions to be kept the same, or any differences to be recorded and controlled. Time of measurement can matter because a plant’s water content, posture, temperature, light exposure, or other properties may change during the day. If one plant is measured in the morning and the other in the evening, a difference in the readings may be caused by time rather than by a real difference between the plants. Time has then become an additional influencing, or confounding, factor.

The best procedure is to measure both plants at the same time of day, using the same instrument and method, and to repeat measurements when suitable. This makes the comparison more reliable. Therefore, option A is correct. The statement that plants never change is false, and neither morning nor evening is automatically more scientific. Consistent observation conditions are essential for a fair test.

A conclusion should be based on recorded evidence and observations. Choose conclusions supported by data.

The direct answer is A: record the actual reading using a suitable balance. An estimate such as “about ten grams” is approximate and may hide important differences. Mass should be measured with an appropriate balance, the reading should be read carefully at eye level when relevant, and the value should be recorded with the instrument’s suitable precision and unit. Option A is correct because it replaces guessing with an observable measurement. Option B, colour, describes appearance and does not give mass. Option C is wrong because repeating the same guess does not create new evidence or greater precision. Option D is wrong because another person’s opinion is not a calibrated measurement; another observer may help check a reading, but opinion alone cannot replace an instrument. Precision also depends on choosing an instrument suitable for the object and expected mass. Memory cue: measure the quantity with its proper instrument; never improve precision by repeating a guess.

A scientific question should have an objective measurable outcome. Replace value judgements with data-based criteria.

Observing several representative locations gives a better estimate of the whole area. Examine diversity of sampling sites.

Different volumes may affect colour intensity so volume should be kept constant. Control observation conditions.

Preliminary observation helps identify testable patterns and questions. Treat observation as the beginning of investigation.

The word better should be defined using a measurable outcome such as germination or growth. Clarify vague terms.

The difference may result from unclear criteria conditions or instruments. Do not blame a person without evidence.

In science observations and questions continually guide one another. Understand this as an ongoing process of inquiry.

The word quickly describes a rate so measuring time is necessary. Look for both change and time in rate-based observations.

A standard instrument and equal depth provide comparable measurements of transparency. Choose controlled methods for objective observation.

This question tests a measurable relationship between moisture and earthworm number. Look for controlled criteria such as equal area.