If someone told you that a blade of grass, the sun, the air you breathe, and your body were composed of the same incredibly small particles, would you believe them?

it creates acid rain

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.

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.