Answer:
E. are found in nitrogen-fixing cyanobacteria AND are used to protect nitrogenase.
Explanation:
Heterocysts are specialized cellular compartments found in nitrogen fixing cyanobacteria. They provide the ideal anaerobic environment for nitrogen fixation since nitrogenase enzyme cant work in presence of oxygen. Hence, in a cyanobacteria both the oxygen requiring photosynthesis process and the oxygen sensitive nitrogen fixation process takes place simultaneously.
Heterocysts have an additional cell wall made of glycolipid that provides a hydrophobic barrier to oxygen. They are involved in production of nitrogenase and other proteins that are required for nitrogen fixation. They also degrade photosystem II which is responsible for producing oxygen and produce proteins which remove any remaining oxygen.
The correct answer is '<span>Oxygen is used up as algae is decomposed, reducing the amount available to other organisms.</span>' The additional nutrients in the water will result in an algal bloom. These algae will result in drastic oxygen fluctuation, from oxygen rich conditions during the day as algae photosynthesize, to anoxic conditions during the night when the algae respire. However, the algal bloom will eventually deplete the available nutrients, resulting in a vast algal die off. The decomposing algae result in anoxic conditions, and the effects are sometimes very obvious, with fish gasping for breath and dying.
Answer:
A means a turning motion around a central axis tq
