Which of the following could result in secondary succession? the formation of a tall sand dune on a previously grassy beach
a vast glacier in motion forming a U-shaped valley in its wake
a volcanic eruption that covers most of what used to be a forest
an introduced species that destroys all the native plants in an area

D. an introduced species that destroys all the native plants in an area

Explanation:

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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blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

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