Which provides a baseline for an experimental investigation? hypothesis
control group
dependent variable
independent variable

answer; ///i believe its: ///(embolus);

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.