Tiny Builders Reading Passage
Grade 1 Science Read-Aloud
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Tiny Builders: The Story of Your Cells
How your body systems, organs, tissues, and cells work together!
Part 1
The Seven Great Body Teams
Look at you! You have seven big body systems working inside you right now. Each system is a team doing a huge job to keep you alive and healthy:
Skeletal Your bones
Muscular Helps you move
Nervous Brain & senses
Digestive Breaks food down
Respiratory Breathes air in
Circulatory Pumps your blood
Excretory Cleans out body waste
Part 2
What is an Organ?
Every system is made of special body parts called organs. An organ is a body part that has one special job to do.
Digestive Team Example: Your stomach is an organ! It works side-by-side with your mouth, your food pipe (esophagus), your liver, and your intestines. They team up to chew, swallow, and break down food so your body gets energy!
Part 3
What Are Tissues?
What makes up an organ? Tissues! Body tissues are layers of tiny helpers that stick together. There are many kinds of tissue: muscle tissue, bone tissue, skin tissue, blood tissue, and nerve tissue. Every tissue is made of matching cells that do the exact same job!
Part 4
Cells: The Tiny Building Blocks
All tissues are made of cells. Cells are the teeny-tiny building blocks of your whole body.
Cells are so small that no one knew they existed until people invented microscopes about 400 years ago! A microscope magnifies cells, making them look big enough to see.
You have trillions of busy cells living inside you right now!
The Microscope Makes invisible cells look huge!
How Your Body Fits Together (Smallest to Largest)
1. Cells
2. Tissues
3. Organs
4. Systems
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2
Cell Superheroes & How They Grow
Different cell shapes, special jobs, and cell multiplication!
Part 5 & 6
Different Shapes for Different Jobs
Over 200 Cell Types!
Red Blood Cells
Shape: Round like bagels with dents instead of holes!
Job: Ride in your blood carrying healthy food and oxygen to your whole body.
Skin Cells
Shape: Packed tight together like a solid brick wall!
Job: Protect you from dirt and weather. Your skin is your biggest organ!
Nerve Cells
Shape: Long with wire-like branches!
Job: Send lightning-fast messages from your brain to your hands and feet.
Muscle Cells
Shape: Long, lean, and stretchy like rubber bands!
Job: Stretch and squeeze so you can walk, run, smile, and jump!
Everything you do—breathing, eating, running, and sleeping—needs working cells. All living things have cells!
Part 6
Cells Are Alive! The Multiply Magic
Cells do not last forever. Some live for a few days, and some live for years. When you get a scrape, or cells wear out, your body makes brand new cells by dividing:
1
One Cell
2
Splits to Two
4
Becomes Four
8
Becomes Eight!
Old cells die, and brand new cells take their place every single day!
First Grade Detective Check!
1. What tool makes tiny cells look big?
Telescope Microscope Sunglasses
2. Which cell looks like a bagel with a dent?
Skin Cell Red Blood Cell Nerve Cell
3. What is your body's largest organ?
Your Skin Your Stomach Your Liver
4. Draw 1 cell dividing into 2 new cells!
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