Table of Contents Energy from the Sun 4 Making Food 10 Parts of a Plant 16 Plant Reproduction 24 Cycles of Life 32 Plants and People 38 Glossary 46 Index 47 Show What You Know 47 Websites to Visit 47 About the Author 48
Energy from the Sun Running kicking a ball singing reading a book sleeping all these activities require energy Your brain needs energy to think your heart needs energy to beat and your lungs need energy to breathe In fact all living organisms need energy for ten major processes 4
10 Life Processes Together these processes are called an organism’s metabolism Growth life is always growing and developing Absorption transporting materials through membranes Reproduction creating more organisms of your own species Digestion grinding up and using food substances Excretion releasing wastes from the organism Response to stimuli responding to changes in the environment Movement even plants move Assimilation building new materials from nutrients Respiration breathing Circulation distributing fluid such as blood throughout the body Touch Me Not Plants can move just like all other living creatures but it’s usually too slow for a person to see Not so with the touch-me-not or bashful plant Mimosa pudica When someone touches or shakes the leaves of this plant it immediately folds up and droops Scientists believe the plant is trying to protect itself from harm After a few minutes the leaves reopen 5
