How do the lines in an atomic emission spectrum provide evidence that electrons can only exists in specific energy levels within the atom?

Dermal tissue in plants stores 1.extra food 2.transports water and nutrients 3.transports waste materials 4.is similar to epithelial cells in animals

The distant ancestors of tigers may have had bodies without stripes. use the theory of natural selection to explain how tigers may have evolved to have stripes.

Which label identifies the part of the atp molecule that changes when energy is released in the cells of all living things