Coral reefs are ideal breeding grounds for a variety of fish and sea creatures, and coral is considered a foundation species. unfortunately, coral reefs are fragile ecosystems and are easily disrupted. because coral contain calcium carbonate deposits, one situation poses a growing threat to coral as well as the many organisms that are dependent on them. that situation is
a) the disappearance of certain species of fish due to overfishing.
eliminate
b) the deposition of calcium on the reefs, due to the leaching of calcium from dead organisms.
c) over exposure to sunlight due to the relatively shallow nature of the ocean around the reefs.
d) acidification of the ocean caused by increased atmospheric carbon dioxide emissions that dissolve in water.

The correct answer is option D) "acidification of the ocean caused by increased atmospheric carbon dioxide emissions that dissolve in water".

Explanation:

According to scientific evidence, coral reefs and many organisms that have calcium carbonate shells are affected by high carbon dioxide emissions. When sea water absorbs carbon dioxide, the pH of water is reduced in what is known as acidification of the ocean. In consequence, less calcium carbonate is available for coral reefs to be used as shells, which traduces as a major threat for their populations.

hey bro i looked it up on google the structure of the eye-spot in euglena viridie, e. ehrenbergii, and phacus pyriyorme is not as franzé haa described it. the so-called “crystal body” and “lens bodies” were not found in any of the individuals of the species examined by me. as earlier observers have stated, the eye-spot consists simply of a mass of pigment granules arranged in a single layer, and probably embedded in a protoplasmic framework, but the latter could not be seen, and its presence was only inferred from the fact that the pigment granules must be held together in some way, thd the eye-spot as a whole is capable of expansion, and that the pigment granules can be separated from each other.

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