This engaging science passage for Grade 4-5 students explores animal internal structure and how organs work together to keep animals alive and healthy. Students learn about the circulatory system with the heart pumping blood, the respiratory system with lungs breathing air, the digestive system with the stomach breaking down food, and the nervous system with the brain controlling the body. The passage connects these concepts to students' own internal organs, helping them understand the hidden structures that keep them alive. Audio-integrated content supports diverse learners. Aligned with NGSS science standards 4-LS1-1, this passage includes vocabulary support, Spanish translation, differentiated text, comprehension questions, writing activities, and graphic organizers to help students describe how internal structures perform functions essential for animal survival.
Written by Workybooks TeamPublished by Workybooks
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Animals have internal structures inside their bodies that keep them alive. Internal structures are parts you cannot see from the outside, like bones, a heart, lungs, a brain, and a stomach. Each of these structures has an important job to do.
Your bones are hard structures that give your body shape and protect soft parts inside. Think of bones like the frame of a building that holds everything in place. Your heart is a muscle that pumps blood through your body, delivering oxygen and nutrients to all your cells. Your lungs are organs that help you breathe by taking in oxygen from the air and removing carbon dioxide.
Your brain is the control center that tells your body what to do. It helps you think, remember, and move. Your stomach is an organ that breaks down food so your body can use it for energy. Without a stomach, you could not get nutrients from the food you eat.
Plants also have internal structures, but they are very different from animal structures. Plants have roots, stems, and tubes that carry water, but they do not have hearts or brains. Animals need different structures because they move around, eat other living things, and breathe in different ways than plants.
Interesting Fact: Your heart beats about 100,000 times every single day, pumping around 2,000 gallons of blood through your body!
What are internal structures?
Parts you can see outside the bodyParts inside the body you cannot seeOnly bones and musclesParts only plants have
What job does the heart do?
It helps you think and rememberIt breaks down food for energyIt pumps blood through the bodyIt gives the body shape
What do bones do for the body?
They pump blood to cellsThey help you breathe oxygenThey break down foodThey give shape and protect organs
Why do animals need different structures than plants?
Animals are bigger than plantsAnimals move, eat, and breathe differentlyPlants do not need any structuresAnimals live longer than plants
What would happen without a stomach?
You could not get nutrients from foodYou could not breathe oxygenYour bones would be softYour heart would stop pumping
Which organ is the control center?
HeartLungsBrainStomach
Plants have hearts and brains like animals.
TrueFalse
What does the word organ mean?
A type of bone in animalsA body part with a special jobFood that gives you energyAir that you breathe in