blue-violet (chlorophyll a) & red (chlorophyll b). that's why it appears to be green.
C. Dependent variable
The independent variable is what you want to change (ex amount of light given to plants)
The dependent variable is what changes because of the independent variable (ex the height of the plants)
So Independent is what you change, Dependent is what you measure
The nail breathes oxygen to live. The nail breathes the oxygen dissolved in the water.
Given that the aquarium is a small bioma there is not enoguh source of oxygen to replace the oxygen consumed by the snail, except for the oxygen produced by the aquatinc plants inside the aquarium.
Plants produce oxygen through the process named photosynthesis. Photosynthesis requires light.
Given that the aquarium is kept dark, the aquatic plants cannot carry out the process of photosyntthesis and so there will not be generation new oxygen and the snails will die after they do not have oxygen to breath.
I
It will can cause infertile offspring (the offspring can't have kids)