Cells come from cells; electron arrangement drives chemistry; electric current; Earth's interconnected spheres
Below is how the official curriculum organizes it. Each strand will get full lessons like the ones in Grade 1 Mathematics.
Asexual reproduction (mitosis); sexual reproduction (meiosis) and human reproduction
Periodic table; electron arrangement; how elements form compounds
Electric circuits; voltage, current and resistance
Matter cycles and energy flow among biosphere, geosphere, hydrosphere and atmosphere; sustainability; First Peoples views of interconnectedness