In relation to the scientific method, explain each of the following - Leaving Cert Biology - Question 7 - 2011

A theory is a well-substantiated explanation that combines facts, laws, and hypotheses. It serves as a framework to understand phenomena based on extensive experimental evidence. Theories can be modified with new evidence but are generally supported across multiple experiments.

Using seeds from one parent plant ensures genetic uniformity, minimizing genetic variation that could affect the results of the experiment. This helps in isolating the effects of the variable being studied, such as the mineral's impact on growth.

The scientists may have sterilised the compost using heat or autoclaving, which effectively kills microorganisms and prevents contamination.

Sterilising the compost is crucial to eliminate potential contaminants that could interfere with the growth of the wheat plants, ensuring reliable results by controlling environmental variables.

The division into two equal groups was likely done to establish a control group and an experimental group, allowing comparisons to be made. This helps in understanding the impact of the mineral on growth effectively.

Keeping the two groups of plants under identical conditions ensures that any observed differences in growth can be attributed directly to the variable being tested, in this case, the mineral, rather than extraneous factors.

Temperature.

Light intensity.

Repeating the investigation several times is essential to ensure statistical reliability and robustness of the results. It minimizes errors and allows researchers to validate their findings confidently before making them publicly available.