Explanation:
When conducting a melting point experiment, if we were to heat a sample quickly. Large amount heat is provided instantly which would melt the crystals in the tube very quickly, even before the temperature of the thermometer reaches to that level. So the observes melting point would be much lower than the actual melting point when sample is heated slowly.
The constents would be anythign that stays the same in ever experiment.
Example: Growing sunflowers in different liquids
The constants could be: Type of dirt used to grow each, amount of liquid used to water, and the type of sunflowers grown.
Predation, because the pitcher plant is preying on the insects.