In my opinion and experience, one of the most powerful and useful strategies that a science teacher can use is deliberative, planned questioning. This can take many forms, and I do not mean to imply that planned questioning strategies are purely prescriptive and therefore one size fits all. Although I think they should be planned and structured, questions should also be flexible and tailored to specific situations, students, and concepts being discussed.
As a teacher and as a teacher educator, one resource that I often use for thinking about questioning strategies is a chapter by Jos Elstgeest in the book Primary Science: Taking the Plunge (Harlen, Elstgeest, & Jelly, 2001). Hans Andersen introduced me to this work in 1995, when I was a student in his in science education methods. Although written for the elementary school teacher, this work is applicable to all levels of science teaching.
Elstgeest begins by discussing what makes a question a "wrong question", namely that is wordy and might itself contain the answer, indicating that it aims at pure recall. On the other hand, "productive" questions lead a student to show (rather than say) that they know the answer. These "productive" questions can be attention-focusing questions (e.g. "What do you notice about..."), measuring and counting questions (e.g. "How many of..."), comparison questions (e.g. "In how many ways do these things differ?"), or my favorite types of questions: action questions (e.g. "What would happen if...") or problem-posing questions (e.g. "Can you find a way to...").
How do you use thoughtful, planned questioning in your own teaching?