Autotrophs use the to make organic molecules. o₂ is produced in the . the light reactions involve a series of conversions. an electron carrier called drives the calvin cycle. h₂o provides for the light reactions.

the answer is d. chordata

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.