True ..In animals, the female mitotic sequence produces only one ovum; the other three haploid cells become "polar bodies".
The Marcellus Shale also categorized as the Marcellus formation is a marine sedimentary rock unit of middle Devonian age found in eastern North America. It elongates throughout the major of the Appalachian Basin.
The shale comprises huge unexploited reserves of natural gas, which makes it an attractive target for export and energy development. There are comparatively scarce presences of fossilized marine fauna found in the Marcellus, however, these fossils are still essential to paleontology.
For example, the Marcellus comprises the primogenital known varied assemblage of thin-shelled mollusks, still possessing well-preserved shell microcomposition. It is also where goniatite, an extinct shelled swimmer identical to a squid, make their initial presence in the fossil record.
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They are dangerous to the environment because they have no natural competition. That being said they have nothing to keep their population in check, therefore, taking away food, and habits from all the other species. Thus, causing species to die out, which in turn ruins the food chain.