3) What are the two most likely causes of the dead zones? (please don't use humans as a cause, list specific actions or byproducts of humans)

4) Describe how fertilizers cause hypoxia and consequently dead zones in coastal ecosystems.

The coastal upwelling and changes in wind and water circulation patterns is the main natural cause of dead zones.

Fertilizers cause hypoxia due to the over growth of algae on the surface of water bodies.

Explanation:

Coastal upwelling is the cause of dead zones in which water that is present in depth comes to the surface of ocean due to the movement of water because of wind. Fertilizers cause hypoxia due to the over growth of algae on the surface of water bodies. The fertilizers increases the algal growth by providing nutrients necessary for its growth. This over growth decreases oxygen concentration in water and affect marine organisms.

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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