Cells: Structure and Function
Aligned to MS-LS1 — Next Generation Science Standards.
What this lesson teaches
All living things are made of cells — the basic unit of life. Cells have parts (organelles) that each do a job, and they work together as a system, just like organs in a body.
Worked examples
Example 1
A plant cell's chloroplasts capture sunlight to make food, while the nucleus directs activities and the membrane controls what enters — parts cooperating as one system.
Example 2
An animal cell has no chloroplasts and no rigid wall, which is why a plant stands up on its own and you do not.
Example 3
A cell is the smallest thing that is alive. A virus has genetic material but no cell machinery, which is why biologists argue about whether it counts.
Practice questions
- Name two organelles and what each does.
- How is a cell like a tiny factory?
- Why do scientists call the cell the basic unit of life?
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
Células: estructura y función
Todos los seres vivos están formados por células, que son la unidad básica de la vida. Las células tienen partes (organelos) que cumplen funciones específicas y trabajan juntas como un sistema, igual que los órganos en el cuerpo.
Ejemplo 1: Los cloroplastos de una célula vegetal capturan la luz solar para producir alimento, mientras que el núcleo dirige las actividades y la membrana controla lo que entra y sale: partes que cooperan como un solo sistema.
Ejemplo 2: Una célula animal no tiene cloroplastos ni pared rígida, por eso una planta se sostiene sola y tú no.
Ejemplo 3: Una célula es lo más pequeño que está vivo. Un virus tiene material genético pero no maquinaria celular, por eso los biólogos discuten si cuenta.
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