Hypothesis relating chlorophyll presence to starch production:
If chlorophyll is absent, then plants will not be able to produce starch.

Hypothesis relating light to starch production:
If light is absent, then plants will not be able to produce starch.

Hypothesis relating carbon dioxide absorption to photosynthesis:
If plants undergo photosynthesis, then they should absorb carbon dioxide from the environment (water for aquatic plants); these molecules are used in the Calvin cycle for carbon fixation.

Hypothesis relating oxygen production to photosynthesis:
If plants undergo photosynthesis, then they should release oxygen during the light reactions.

What pigments could you identify from the paper chromatography? Based on the absorption spectra of chlorophylls a and b, which hues of green likely represent the two bands of chlorophyll?
Green bands represent chlorophylls, yellow are carotenoids and xanthophylls.
Chlorophyll a absorbs less blue and appears blue-green; chlorophyll b is yellow-green.