Describe the major features of mid-ocean ridges, deep sea trenches, and abyssal plains and their relative ages.

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thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.

name and explain one of the event that occurs during meiosis that increases the variation in offspring even more than simple reproduction?