Science and Technology K–6 · Year 3
Bean in a jar: watching a plant life cycle begin
Science understanding: Biological sciences
The idea
A seed germinates into a seedling with a root and a shoot, the first stage of a plant life cycle that a learner can measure day by day.
What you need
- 3 dried bean seeds (broad bean or kidney bean) per learner, soaked overnight
- 1 clear glass jar or clear plastic cup
- paper towel and cotton wool to line the jar
- water in a spray bottle
- ruler marked in millimetres
- a warm spot out of direct sun, 20 to 25 degrees Celsius
How to do it
- Line the inside of the jar with paper towel and fill the middle with damp cotton wool so the towel stays pressed to the glass.
- Push three soaked beans between the towel and the glass, evenly spaced, halfway up the jar.
- Spray the towel until damp each day; never let water pool at the bottom.
- Each school day, draw the bean and measure the root length and shoot length in millimetres. Record them in a table with the day number.
- Note the day the seed coat splits, the day the root appears and the day the shoot appears.
- After 14 days, graph shoot length against day as a column graph.
- Transplant the seedling into soil and keep observing until it flowers and sets pods, to see the cycle close.
What you should see
The seed coat splits and the root emerges first; the shoot follows some days later and turns green in light. The root always appears before the shoot, and the root grows downward whichever way the seed was placed. Three beans give three replicates; the class compares the day of germination and the daily growth across jars, and those measured days and millimetres are the result.
What changes
- What you change
- day number (an observation over time, not a fair test)
- What you measure
- root length and shoot length in millimetres
- What you keep the same
- water
- warmth
- same seed type
Common misconceptions
Each of these ideas is wrong, and the activity is a chance to test it.
- Seeds need soil to germinate (they need water, warmth and air; soil comes later).
- The shoot comes out first because plants grow upward.
- Seeds need light to germinate (most do not; the seedling needs light afterwards).
Safety card
Hazards
- mould on over-wet towel
Controls
- keep towel damp not wet
- discard any mouldy jar sealed in a bag
Note
Risk assessment before the lesson using Primary RiskAssess or the school's own template.
Curriculum references
The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.
- Science and Technology K-6 Syllabus (2017), current, taught until 2026; code read from the syllabus document on 22 September 2026ST2-4LW-SST2-1WS-S
- Science and Technology K-6 Syllabus (2024), implemented from 2027; NESA's timeline is 2026 plan and prepare and 2027 start teaching, and schools may choose to implement it during 2026; code read from the outcomes page on 22 September 2026ST2-DAT-01
- Australian Curriculum v9AC9S3U01AC9S3I03AC9S3I04
Sources
The pages the author read to write this activity.