Given a scientific passage and an answer, generate a question for the given answer.

Passage: Gene expression and protein synthesis are usually considered the same molecular process. Answer: protein synthesis
Gene expression and what else are usually considered the same molecular process?

Passage: A metallic bond is the force of attraction between a positive metal ion and the valence electrons that surround itboth its own valence electrons and those of other ions of the same metal. The ions and electrons form a lattice-like structure. Only metals, such as the copper pictured in the Figure below , form metallic bonds. Answer: metallic bond
What is the force of attraction between a positive metal ion and valence electrons?

Passage: The size and shape of the beak is related to the food the bird eats and can vary greatly among different birds. Parrots have down-curved, hooked bills, which are well-adapted for cracking seeds and nuts ( Figure below ). Hummingbirds, on the other hand, have long, thin, pointed bills, which are adapted for getting the nectar out of flowers ( Figure below ). Hawks, eagles, falcons and owls have a sharp, hooked beak. Answer: beak
What characteristic of birds is related to the food they eat?