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Grow It 3-5 / Week 02 / Thursday
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Week 02 · Seeds and Germination

Thursday

Warm or cold?
// How a sleeping seed wakes up
⏱ about 15 min

Thursday: Warm or Cold?

Rocket has a plan. "Let's put one bean cup in the fridge and one on the shelf!"

Then he grabs a third cup. "And this one by the window, and this one with no water!"

Raven stops him. "What do you notice? You changed lots of things at once."

Nova hovers between the cups. "If you change many things, how will you know which one mattered?"

Beans like it warm

Beans are warm-weather plants.

They grow best when soil and air are warmer than 60 degrees Fahrenheit.

Soil of 65 to 85 degrees is just right for beans.

In soil that warm, bean seedlings come up in about 7 to 10 days.

When soil is colder than 60 degrees, far fewer bean seeds germinate.

Beans grow best above how many degrees Fahrenheit? Type the number.
In warm soil, bean seedlings come up in about 7 to how many days?

A fair test

A fair test changes only one thing.

Everything else stays the same.

Then you know the one change caused what you see.

  • Change one thing: for example, warm spot or cool spot.
  • Keep the same: kind of bean, cup, towel and water.
  • Measure: how many beans sprout each day.
MAKE IT FAIR
  • Read the question.
  • Tap your answer.
You want to test warmth. What should you change?
What should stay the same in both cups?

Read a practice table

Here is a made-up practice table. These are made-up practice numbers, not real results.

A class put 10 beans in a warm cup and 10 in a cool cup.

DayWarm cup: beans sproutedCool cup: beans sprouted
Day 210
Day 461
Day 693
In the practice table, how many beans sprouted in the warm cup by Day 6?
WHY THIS EXERCISEThe warm cup had 9 sprouted beans by Day 6 in this made-up table.
Statement about the practice tableTrue or false?
The warm cup sprouted more beans by Day 6.?
The cool cup sprouted the most on Day 4.?
WHY THIS EXERCISEIn every row, the warm cup is ahead, which matches what beans need.
Safety first
Ask a grown-up before you move any cup.
Never use a stove, oven or heater to warm a cup.
Draw two bean cups set up for a fair warmth test. Label what stays the same.

Fair-test pros! Tomorrow we meet tough seed coats and learn a soaking trick.

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