"But how does it get so long?" asked Masha from the front row.
The bell rang, and Mr. Petrov’s 6th-grade biology class scrambled to their seats. On the whiteboard, the title of the day’s presentation flickered:
He pointed to the first slide: a microscopic view of a root tip. "At the very bottom, we have the . Think of it as a helmet. It’s tough and slippery, protecting the delicate cells as the root punches through rocks and hard soil."
On the next slide, a cluster of tiny, active cells appeared. "Right behind the helmet is the . These cells are the engines. They never stop splitting, creating the new life that pushes the root deeper."
"That’s the ," Mr. Petrov replied, showing a diagram where the cells looked like they were being stretched like taffy. "They don't divide anymore; they just grow longer, physically shoving the root tip into the earth."
As the presentation ended, Mr. Petrov handed out small magnifying glasses and sprouted beans. "The slides are over," he said with a wink. "Now, go find the 'helmets' and the 'hairs' yourselves."
Finally, he showed the top part of the root, where it met the stem. "The . This is the highway. Once the root hairs grab the water, this zone pumps it all the way up to the leaves so the tree can grow."
The most popular slide came next. It looked like a fuzzy caterpillar. "This is the (or Maturation). Those 'hairs' you see aren't hair—they are Root Hairs. They increase the surface area so the plant can drink up every drop of water and mineral it can find. This is where the plant breathes and eats."
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