Question

scientists study salamanders and their ability to regenerate lost legs and tails. what additional information is essential for scientists to understand in order to apply this ability to humans who have lost limbs?
how quickly the body parts regenerate
how similar salamanders are to humans
which body parts are most often lost
which genes control regeneration

Explanation:

To apply salamander limb - regeneration ability to humans, understanding the genetic basis (which genes control regeneration) is crucial. Knowing gene - level mechanisms can potentially be manipulated or applied in human contexts. Similarity (while somewhat relevant) is too broad without genetic details. Regeneration speed and common lost body parts are less directly related to applying the ability at a functional level for humans.

Answer:

which genes control regeneration