3-LS1 Life cycles
Aligned to 3-LS1 — Next Generation Science Standards.
What this lesson teaches
Every living thing goes through a life cycle: it is born, it grows, it makes new living things, and eventually it dies. Different plants and animals have life cycles that look different but follow the same pattern.
Worked examples
Example 1
A butterfly starts as an egg, hatches into a caterpillar, forms a chrysalis, and comes out as an adult butterfly that lays new eggs. A bean plant grows from a seed, becomes a plant with flowers, and makes new seeds.
Example 2
A frog begins as an egg in water, hatches as a tadpole with a tail, grows legs, and becomes an adult frog.
Example 3
All life cycles share the same steps — born, grow, reproduce, die — even though a mayfly lives a day and a tortoise lives a century.
Practice questions
- What are the main stages in a butterfly's life cycle?
- How is a plant's life cycle similar to an animal's?
- Draw or describe the life cycle of a frog in order.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
3-LS1 Ciclos de vida
Todo ser vivo pasa por un ciclo de vida: nace, crece, produce nuevos seres vivos y, al final, muere. Las plantas y los animales tienen ciclos de vida que se ven diferentes, pero siguen el mismo patrón.
Ejemplo 1: Una mariposa comienza como huevo, sale como oruga, forma una crisálida y emerge como mariposa adulta que pone nuevos huevos. Una planta de frijol crece a partir de una semilla, se convierte en una planta con flores y produce nuevas semillas.
Ejemplo 2: Una rana empieza como huevo en el agua, sale como renacuajo con cola, le crecen patas y se vuelve rana adulta.
Ejemplo 3: Todos los ciclos de vida comparten los mismos pasos — nacer, crecer, reproducirse, morir — aunque una efímera viva un día y una tortuga un siglo.
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