The article provides science educators with definitions of inquiry and its levels, relating them to real-world scientific processes. Such an educational shift entails a fundamental cultural change in the epistemology of science learning in schools, shifting it from "instructionism" to social constructivist learning. The highest level of inquiry, open inquiry, simulates and reflects the type of research and experimental work that is performed by scientists, and demands high-order thinking capabilities (i.e., questioning, designing an experimental array, critical and logical thinking, reflection). Students who participate in an open inquiry project demonstrated ownership and responsibility for determining the purpose of the investigation and the question to be investigated as a scientist would. We present a model that has been implemented in Israel's high school biology teaching for the past twelve years. The model consists of several components, each of them independently proven important to inquiry teaching by the relevant research literature available. In the article, we present the components of our model, emphasizing the importance of each component. The components (development, implementation, support, and control) at the heart of the model presented here are based on numerous projects and researches from the literature. (Contains 2 tables and 1 figure.)