Study GuidePlant Biology–Themes of Plant Biology1. Flowering Plants as “Typical” PlantsWhen most people hear the wordplant, they picture the plants they see every day. This might be acactus in the desert, tall grasses across a prairie, or large trees growing near a river. All of thesefamiliar plants belong to a group calledangiosperms, or flowering plants.1.1Why Flowering Plants Seem So CommonIn today’s world, angiosperms make up most of the large, visible plants in temperate regions and thetropics. With the exception of conifer trees, such as pines and firs, flowering plants dominate thelandscapes around us.This was not always the case. In earlier geological periods, other plant groups—like gymnosperms,ferns, and fern relatives—were the dominant forms of vegetation. Even earlier, before plants lived onland at all, life existed mainly in water, where bacteria, algae, and protists were the first organisms tothrive.1.2How Important Are Angiosperms?There are nearly300,000 known speciesof flowering plants worldwide. They are essential to life onEarth. Angiosperms provide us with food, building materials, and clothing fibers. They feed livestockand shape the landscapes we find beautiful, from natural forests to gardens and parks.Most importantly, flowering plants capture energy from sunlight through photosynthesis and convert itinto energy that animals—including humans—can use. In this way, angiosperms support nearly all lifeon land.1.3Why Scientists Focus on Flowering PlantsBecause angiosperms are so important and widespread, they are studied extensively. Scientistsresearch them in laboratories, greenhouses, and natural environments around the world. As a result,we know more about flowering plants than about any other groupof plants.In introductory plant biology courses, the wordplantusually means an angiosperm unless statedotherwise. Flowering plants are often used as the model, or “typical,” plants for learning basic plantstructure and function.Preview Mode
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