It wasn't about wanting to know about photosynthesis, the original question was really about the oxygen tanks. Kids very often are looking for a simple answer. Even though the real answer is far more complex.

As a Dad who helped raise 4 Daughters, (a CPA, a Triage Nurse, PHD Mech Engineer, and a Computer Forensic Expert for the FBI), teaching at home is a crucial part of parenting. Beyond offering a wide variety of materials to learn from, (we built a library of books that filled my office), and being ready to answer those oxygen tank questions, you need to show and make asking those questions and learning from them fun.