Part I
Plant Basics
In this part . . .
This part introduces you to some of your neighbors on planet earth that you might not have noticed much before. Plants seem pretty different from people, and although many people appreciate the beauty of plants, not everyone takes the time to really get to know them.
In this part, you take a closer look and discover that plants have many similarities to you. For example, like all living things, plants are made of cells, tissues, and organs. Plants even have sex! In fact, many of the foods you eat are the result of plant sexual reproduction. You can find out all about these similarities as you read this part, in which I present the fundamentals of plant structure that are essential to understanding plant function and evolution.
Chapter 1
Exploring Botany
In This Chapter
Building plants one cell at a time Finding out about how plants work Connecting plants and people Botany is the study of plants, including plant structure, function, reproduction, diversity, inheritance, and more. Plants may seem like theyâre part of the background of your life, when really theyâre at the center. The food you eat, the clothes you wear, the materials that make up your home â all these things depend upon plants. Plants remove carbon dioxide from the atmosphere, helping to keep your planet from getting too warm for life as you know it. They provide homes for insects and other animals, filter impurities out of ground water, and help protect shorelines from erosion.
And beyond all these useful things plants do, theyâre just cool! Plants have many unique strategies that help them survive in all different kinds of environments. They trap and trick insects, grow in the ground or up in the rainforest canopy, and manage to survive everywhere from the glacial arctic to the hot, dry deserts. They seem so different from people, and yet when you really look at how plants grow and function, youâll be surprised at how similar they are to you. This chapter offers an overview of the science of botany, giving you a peek into the mysteries of plants.
Taking a Close Look at Plant Structure
You might not think so, but plants are a lot like you. Their bodies are made of cells (see Chapter 2) that are organized into tissues (see Chapter 3) that form the familiar plant organs of roots, stems, and leaves (see Chapter 4). Plant cells use the same basic chemistry as your cells, storing information in DNA, using carbohydrates for energy, and putting proteins to work. And your cells and plant cells are both eukaryotic cells, meaning they have a similar structure that includes a nucleus and cellular organelles.
Organizing plants into roots, stems, and leaves
Plants reach out to the sun with their leaves, absorbing light energy so that they can make sugar through the process of photosynthesis. Most leaves are flat because thatâs the best shape for spreading out and catching lots of sun. But plants can also make leaves in different shapes for different purposes, such as tendrils for hanging on and climbing, spines for protecting the plant against grazing animals, or thick, fleshy leaves for storing water. Plant stems support the leaves, holding them in different arrangements so that they donât shade each other and can absorb the most light. New plant growth occurs at stem tips as cells divide to make stems grow longer and to build new leaves, branches, and sometimes flowers. Some plant stems, such as those in cacti, are green so that they can do photosynthesis. Other types of stems, such as the runners of a strawberry plant, grow along the ground, sending up new plants at intervals along the horizontal stem. Plant roots are in charge of getting water for the leaves and stems by absorbing water fr... 
