Section 1
Plants Respond to Environmental Stimuli
Plants react to changes in their environment through tropisms. They grow toward light, send roots toward water, and respond to gravity, directing their growth to acquire essential resources.
In this Grade 4 lesson from Science: A Closer Look, Chapter 2: Exploring Ecosystems, students learn how plants respond to environmental stimuli through a process called tropism. They discover how light, water, and gravity each trigger directional growth responses in plants, and explore how adaptations like those of mangrove trees help plants survive in challenging environments. A hands-on shoe box investigation gives students a firsthand look at how plants grow toward a light source when other directions are blocked.
Section 1
Plants Respond to Environmental Stimuli
Plants react to changes in their environment through tropisms. They grow toward light, send roots toward water, and respond to gravity, directing their growth to acquire essential resources.
Section 2
Plants Develop Adaptations for Survival
Plants evolve special features to thrive in challenging ecosystems. Cacti store water in thick tissue, deciduous trees shed leaves during winter, and some plants produce colorful fruits to attract animals.
Section 3
Scientists Conduct Experiments to Understand Plant Behavior
Through careful investigation, scientists like Charles Darwin discover how plants respond to their environment. Experiments with light, water, gravity and chemicals reveal the mechanisms behind plant growth patterns.
Section 4
Roots and Stems Grow in Different Directions
Plant stems typically grow upward against gravity while seeking light, while roots grow downward with gravity toward water sources. These opposing growth patterns help plants access all necessary resources.
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Section 1
Plants Respond to Environmental Stimuli
Plants react to changes in their environment through tropisms. They grow toward light, send roots toward water, and respond to gravity, directing their growth to acquire essential resources.
Section 2
Plants Develop Adaptations for Survival
Plants evolve special features to thrive in challenging ecosystems. Cacti store water in thick tissue, deciduous trees shed leaves during winter, and some plants produce colorful fruits to attract animals.
Section 3
Scientists Conduct Experiments to Understand Plant Behavior
Through careful investigation, scientists like Charles Darwin discover how plants respond to their environment. Experiments with light, water, gravity and chemicals reveal the mechanisms behind plant growth patterns.
Section 4
Roots and Stems Grow in Different Directions
Plant stems typically grow upward against gravity while seeking light, while roots grow downward with gravity toward water sources. These opposing growth patterns help plants access all necessary resources.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter