Squeaks and Jessi use their pretend time machine to go way back in time and meet a creature even older than dinosaurs, called Dimetrodon! First Grade Next Generation Science Standards Crosscutting Concept: Structure and Function: The way an object is shaped or structured determines many of its properties and functions. Disciplinary Core Idea: LS1.A: Structure and Function - All organisms have external parts. Different animals use their body parts in different ways to see, hear, grasp objects, protect themselves, move from place to place, and seek, find, and take in food, water and air (1-LS1-1). Performance Expectation: 1-LS1-1. Use materials to design a solution to a human problem by mimicking how plants and/or animals use their external parts to help them survive, grow, and meet their needs.