When a leaflet is touched, this triggers an action potential in sensing cells at the base of the leaflet. cells at the base of the leaflet respond to this action potential, folding the leaflet inward. if you make a gentle touch that only stimulates the end leaflet, the resulting action potential propagates down the axis that supports all of the leaflets, triggering an action potential in the sensing cells at the base of the adjacent leaflet, then the one next to it, and so on down the line, similar to how electrical signals propagate in the human nervous system. you can watch the progress of this pulse of action potential by watching adjacent leaflets fold inward, one after another. if, instead of a touch, a leaf structure is stimulated with a spark that sends a charge through the structure that holds all of the leaflets, how might you expect the leaflets to behave?

the answer is d p: cell, q: organ, r: organ system, s: tissue

the two answers are a, the population of birds with large beaks will increase on the island, and c, the trait for large beaks will be passed on to future generations through natural selection. the reason for that is because if the birds that have beaks developed for eating small seeds lose all of their food, they will go hungry and eventually starve because they physically cannot eat the large seeds, therefore making the population of large beaked birds higher. also, if the trait of large beaks are dominant on the island over small beaks, then over time the large beaked birds will reproduce more and more, while the smaller beaked birds will reproduce less and less because they can't survive with the food provided. that leads to the trait of small beaks disappearing and the trait of large beaks taking over the island.