Organelle that creates energy for the cell in the form of ATP

Look at the photo of the leaf, which term best describes this leaf ? a-simple.b-parallel.c-lobed.d-tooth.

What is the name of the idea that energy cannot be created nor destroyed

American scientist, linus pauling, was one of many scientists racing to discover the molecular structure of dna. pauling initially thought that the molecule was a triple helix. later, james watson and francis crick unveiled their double helix model, which turned out to be an accurate description of the molecule's shape. why did watson and crick succeed when pauling failed?