Section 1
Cells Build Living Organisms
Cells are the smallest units of living things. All organisms have cells that perform five life functions: growing, using food, removing waste, reproducing, and responding to their environment.
In this Grade 4 lesson from Science: A Closer Look, students learn that cells are the basic building blocks of all living things and explore key vocabulary including cell, organism, oxygen, tissue, organ, and organ system. Students also discover the five life functions that define organisms — growing, using food, getting rid of wastes, reproducing, and reacting to changes in the environment. Hands-on microscope observations of onion skin and leaf slides help students connect these concepts to real plant structures.
Section 1
Cells Build Living Organisms
Cells are the smallest units of living things. All organisms have cells that perform five life functions: growing, using food, removing waste, reproducing, and responding to their environment.
Section 2
Plant Cells Use Special Structures
Plant cells differ from animal cells by having cell walls and chloroplasts. Cell walls give plants rigid box-like shapes, while chloroplasts contain chlorophyll that allows plants to make food from sunlight.
Section 3
Cells Organize Into Complex Systems
Similar cells group together to form tissues. Different tissues combine to create organs with specific jobs. Multiple organs cooperate as organ systems to perform important life functions in plants and animals.
Section 4
Scientists Use Microscopes to Explore Cells
Most cells are too small to see with the naked eye. Scientists use microscopes to magnify cells hundreds of thousands of times, allowing them to study tiny structures and observe how cells function.
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Section 1
Cells Build Living Organisms
Cells are the smallest units of living things. All organisms have cells that perform five life functions: growing, using food, removing waste, reproducing, and responding to their environment.
Section 2
Plant Cells Use Special Structures
Plant cells differ from animal cells by having cell walls and chloroplasts. Cell walls give plants rigid box-like shapes, while chloroplasts contain chlorophyll that allows plants to make food from sunlight.
Section 3
Cells Organize Into Complex Systems
Similar cells group together to form tissues. Different tissues combine to create organs with specific jobs. Multiple organs cooperate as organ systems to perform important life functions in plants and animals.
Section 4
Scientists Use Microscopes to Explore Cells
Most cells are too small to see with the naked eye. Scientists use microscopes to magnify cells hundreds of thousands of times, allowing them to study tiny structures and observe how cells function.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter