The Open Door Web Site : Home Page. The Open Door Web Site is a reference source for both students and teachers.. Free, �international education�, �International Baccalaureate�, Biology, Natural Science, Animals, Plants, ''Living Things'', Ecology, ''Animal Groups'', ''Internet Guide'', Education, Key Stage 3, ''Discovering Natural Science'', 6th grade, 6�me, Growth, feeding, movement, breathing, reproduction, sensitivity, ''science resource'', science, natural science, biology, ''biology reference'', animals, plants, ecology, ecosystems, mammals, amphibians, reptiles, birds, invertebrates, arthropods, movement, ''homework help'', feeding, breathing, growth, sensitivity, reproduction, excretion, education