Where is most of the mass an a atom

Identify the image that doesn’t depict a reproductive strategy. 1st image: a bird feeding their young residing in a nest. 2nd image: a lioness nestled with her young. 3rd image: leaves of a tree during the day time. 4th image: a fish gazing up at what appears to be bubbles or mosquito eggs.

Dna is colied into chromosomes in a cell

What causes darkening of the skin as melanin production increases