Which two biogeochemical cycles depends directly on photosynthesis

Answer is Carbon and Oxygen cycles

The oxygen cycle and carbon cycle are two biogeochemical cycles which depends on photosynthesis process.

Photosynthesis is a process in which green plants capture and use sunlight as source of energy for the synthesis of carbohydrate (food) from carbon dioxide and water. During photosynthesis oxygen is released as a by-product.  

The oxygen released during photosynthesis is used in cellular respiration. During cellular respiration, carbon dioxide is released which is used in photosynthesis. Thus,  oxygen cycle and carbon cycle depends on photosynthesis process.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

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.