I think the veins absorb the photons because they're located at the top part of a leaf while the stomata that serves as the leaf's lungs are found at the under side.
DNA/fingerprints are all unique, therefor it is easy to match a fingerprint to a person thus they use this mechanism in criminal investigations because only one person woul have matching DNA to the prints on the scene, and that is the criminal.
Hope this helps :)
Coevolution happens when the genetic development between two or more species affects the evolution of each other. An example would be hummingbirds and bird-pollinated (ornithophilous) flowers. The ornithophilous flowers give nourishment to the birds with their nectar that has high sugar content. The birds in return aids in the pollination of these flowers.
By common logic you know that water has pH=7
When you add water to something that is acidic, for example you add water to vinegar, you make it less acidic. So the pH from 2 will be higher for instance 3 or 4 or 5 etc.
This happens because pH=-log[H3O+]
