Uranium-238 undergoes alpha decay. therefore, uranium-238 will increase, decrease, stay the same or none of the above

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.

What does the start look like

The fertilized egg  begins to develop into a hollow ball of cells called the blastocyst. 

Special care would be an answer