Protein kinase is an enzyme that promotes phosphorylation of target proteins at specific sites, whereas protein phosphatase catalyzes the removal of a phosphate from a phosphorlated protein. phosphorylation and dephosphorylaytion can function as an on-off switch for a protein's activity, most likely through: A) the removal of one or more peptides
B) A change in the active site structure
C) A change in the optimal temperature at which a chemical reaction will occur
D) A change in the optimal pH at which a reaction will occur

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.