Grade 3 students learn how to classify animals using the key concepts of vertebrates and invertebrates from Chapter 1 of Science: A Closer Look. The lesson covers how structures such as a backbone, legs, and an exoskeleton are used to sort animals into groups, and introduces major animal categories including birds, reptiles, amphibians, fish, and mammals. Students practice observing and recording animal characteristics in charts to apply scientific classification skills.
Section 1
Scientists Classify Animals Using Body Structures
Animals are grouped based on their physical characteristics. The main division separates vertebrates (animals with backbones) from invertebrates (animals without backbones), making them easier to study and understand.
Section 2
Vertebrates Develop Specialized Body Systems
Five groups of vertebrates—mammals, birds, reptiles, amphibians, and fish—have backbones but differ in how they breathe, reproduce, and protect their bodies with features like scales, feathers, or fur.
Section 3
Invertebrates Support Bodies Without Bones
Most animals on Earth lack backbones and use alternative body supports. Some have exoskeletons (outer coverings), while others like jellies and worms have soft bodies supported by water or muscle contractions.
Section 4
Mammals Feed Young With Special Milk
Mammals differ from other vertebrates by having hair or fur, giving birth to live young rather than laying eggs, and producing milk to feed their babies until they can find food independently.
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Section 1
Scientists Classify Animals Using Body Structures
Animals are grouped based on their physical characteristics. The main division separates vertebrates (animals with backbones) from invertebrates (animals without backbones), making them easier to study and understand.
Section 2
Vertebrates Develop Specialized Body Systems
Five groups of vertebrates—mammals, birds, reptiles, amphibians, and fish—have backbones but differ in how they breathe, reproduce, and protect their bodies with features like scales, feathers, or fur.
Section 3
Invertebrates Support Bodies Without Bones
Most animals on Earth lack backbones and use alternative body supports. Some have exoskeletons (outer coverings), while others like jellies and worms have soft bodies supported by water or muscle contractions.
Section 4
Mammals Feed Young With Special Milk
Mammals differ from other vertebrates by having hair or fur, giving birth to live young rather than laying eggs, and producing milk to feed their babies until they can find food independently.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter