What Makes Living Things Grow
Aligned to MS-LS1-5 — Next Generation Science Standards.
What this lesson teaches
How big and healthy an organism grows depends on both its genes and its environment. Genes set the possible range, but factors like food, water, light, temperature, and space determine how much of that potential is reached.
Worked examples
Example 1
Two tomato plants from the same seed packet share genes, but the one grown in rich soil with full sun grows tall and fruitful, while the one kept in a dark closet stays small and pale — the environment shaped the difference.
Example 2
Identical twins have the same genes but different fingerprints, because small differences during development are not written in DNA.
Example 3
Genes set a range, not a value. Good nutrition lets a person reach the top of their genetic height range, but it will not exceed it.
Practice questions
- Measure the height of two identical plants kept in different light and record the numbers weekly.
- Make a chart predicting how changing water, light, or crowding would change a plant's growth.
- Construct an explanation, using your data, for how genes and the environment together shaped each plant's growth.
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
Qué hace crecer a los seres vivos
El tamaño y la salud que alcanza un organismo dependen tanto de sus genes como de su entorno. Los genes fijan el rango posible, pero factores como la comida, el agua, la luz, la temperatura y el espacio determinan cuánto de ese potencial se alcanza.
Ejemplo 1: Dos plantas de tomate del mismo sobre de semillas comparten genes, pero la que crece en tierra rica y con sol pleno se hace alta y da frutos, mientras que la que se mantiene en un armario oscuro queda pequeña y pálida — el entorno marcó la diferencia.
Ejemplo 2: Los gemelos idénticos tienen los mismos genes pero distintas huellas digitales, porque pequeñas diferencias durante el desarrollo no están escritas en el ADN.
Ejemplo 3: Los genes fijan un rango, no un valor. Una buena nutrición deja a una persona alcanzar la parte alta de su rango genético de estatura, pero no lo supera.
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