1. the first choice , hope that helped
Answer:
Undergrowth of water plants hypoxia
Low levels of oxygen.
Explanation:
Eutrophication occur when lake or river has adequate nutrients that will encourage the growth of water plants i.e algae which lead to the depletion of dissolved oxygen in the lake. The growth of algae is increased due to availability of carbondioxide or phosphorus or nutrients required for photosynthesis. This result in tainted drinking water,hypoxia and degradation of recreational activities.
Answer: Hydrogen bonds
Explanation: The CAS9 enzyme affect the bond between the deoxyribose sugar and the phosphate backbone of the PAM sequence in the target DNA