McGraw Hill
Arthropods
Are spiders related to crabs? Study the order of arthropods with a reading selection about animal diversity. It provides details about each class within the order, as well as vivid pictures and explanatory charts.
National Institute of Educational Technologies and Teacher Training (Spain)
Ministerio De Educacion: El Reino Animal
Learn about the animal kingdom including an in-depth look at body characteristics, reproduction, types of cells, ways they obtain food, and evolutionary relationships. Many illustrations and nine interactive activities are included.