Inquiry is a term that appears more and more when there's a discussion of 21st century teaching strategies. It is a very relevant term particularly to the sciences. 

Student inquiry has been defined in the National Science Education Standards as “the activities of students in which they develop knowledge and understanding of scientific ideas, as well as an understanding of how scientists study the natural world".

Inquiry and the National Science Education Standards propose the following elements as components of inquiry-based instruction. Note that these phases essentially constitute a learning cycle: 

Phase 1: 

Students engage with a scientific question, event, or phenomenon. This connects with what they already know, creates dissonance with their own ideas, and/or motivates them to learn more. 

Phase 2: 

Students explore ideas through hands-on experiences, formulate and test hypotheses, solve problems, and create explanations for what they observe. 

Phase 3: 

Students analyze and interpret data, synthesize their ideas, build models, and clarify concepts and explorations with teachers and other sources of scientific knowledge. 

Phase 4: 

Students extend their new understanding and abilities and apply what they have learned to new situations. 

Phase 5: 

Students, with their teachers, review and assess what they have learned and how they have learned it.
Here is my essential question for the group:

How can the use of inquiry help us guide our students to engage in science practice?

To guide this conversation I would like to break it down into a set of questions: 

Question 1. How do traditional approaches differ from inquiry approaches in the science classroom? How do we differentiate the various levels of inquiry? 

Question 2. What are the essential features of inquiry? 

Question 3. How do we design inquiry investigations

Question 4. How do we assess inquiry investigations?

I'll try answering the questions based on some research I had to do to prepare for a College Board workshop on Scientific Inquiry and Reasoning but look forward to your adding more information!