A genetic factor for a trait that is always expressed when it is present is best described as
O
A. dominant
B. Mendelian
C. recessive
D. non-Mendelian
SUO

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.