Developing bird embryos excrete most of their nitrogenous waste as uric acid because .

Because it has a low solubility in water and it  is less toxic to the embryo as compared to other forms of waste

Explanation:

1. Developing bird embryos excrete most of their nitrogenous waste as uric acid,there are many reasons of  this, one the reason is that   it has a low solubility in water and it  is less toxic to the embryo as compared to other forms of waste.

2. Birds and many other organisms like reptile excrete nitrogenous waste in the form of uric acid, because it reduces water loss compared to other nitrogenous wastes, but it  requires more metabolic energy as compared to others to produce.

What's the question?

Well,what i learned was that unlike many other  endothermic  reactions,  photosynthesis  does not absorb energy as heat. instead, during plants absorb energy from sunlight to turn carbon dioxide and water into oxygen and glucose, which is a type of sugar molecule. the energy is stored in the glucose molecules, ready to be used when needed.