The first answer Is A and the second answer is also A
I would say that Science is the term for collected studies on the creation of all things and how time affects them.
A decrease in dissolved oxygen.
This is because oxygen is a byproduct of photosynthesis. If the plants are in water, some of the oxygen they produce will become dissolved in it. Without those plants, you have less dissolved oxygen.
1st view --- G1 phase (growth)
2nd view --- S phase (synthesis)
3rd view --- M / cytokinesis phase (mitosis)