Which statement is true for both photosynthesis and cellular respiration?

What causes darkening of the skin as melanin production increases

What's wrong with this ecological pyramid? (multiple choice)1. secondary consumers should be at the bottom of the pyramid2. the sun has an arrow leading to decomposers 3. primary consumers should come after the sun4. energy retained should increase from the bottom to the top5. the sun should be at the bottom of the pyramid

Ascientific idea becomes valid when it is what?