Identify which of the following is considered quantitative data. 

If all green plants require sunlight for photosynthesis, then any green plant placed in the dark would not synthesize glucose, the end product of photosynthesis. This is the best example of:

Quantitative observations have more accuracy than qualitative observations because, in quantitative observations, the variables are:

A _____ is an assumption made before any research has been done, whereas a _____ is a tested, well-substantiated, unifying explanation for a set of verified and proven factors.