Copyright Pearson Prentice Hall Biology Copyright Pearson Prentice Hall
22–1 Introduction to Plants Photo Credit: © Terry Donnelly/Dembinsky Photo Associates Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall What Is a Plant? What Is a Plant? Plants are multicellular eukaryotes that have cell walls made of cellulose. Plants develop from multicellular embryos and carry out photosynthesis using the green pigments chlorophyll a and b. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall The Plant Life Cycle Alternation of Generations All plants have a life cycle with alternation of generations, in which the haploid gametophyte phase alternates with the diploid sporophyte phase. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall The Plant Life Cycle During the two phases of the life cycle, mitosis and meiosis alternate to produce the two types of reproductive cells—gametes and spores. The diploid (2N) phase is called the sporophyte, or spore-producing plant. The haploid (N) phase is called the gametophyte, or gamete-producing plant. Copyright Pearson Prentice Hall
What Plants Need to Survive In order to survive, plants need: sunlight water and minerals gas exchange transport of water and nutrients throughout the plant body Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Early Plants The first plants evolved from an organism similar to the multicellular green algae living today. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall Early Plants The oldest known plant fossils, about 450 million years old, are similar to today’s mosses. They had a simple structure and grew close to the ground. One of the earliest fossil vascular plants was Cooksonia, which looked similar to mosses living today. Copyright Pearson Prentice Hall
Overview of the Plant Kingdom Plants are divided into four groups based on these features: water-conducting tissues seeds flowers Plants are also classified by other features, including reproductive structures and body plan. Copyright Pearson Prentice Hall
Overview of the Plant Kingdom Evolutionary Relationships Among Plants Flowering plants Cone-bearing plants Ferns and their relatives Flowers; Seeds enclosed in fruit Mosses and their relatives This cladogram shows the evolutionary relationships among the various groups of plants. The four main groups of living plants are mosses and their relatives, ferns and their relatives, cone-bearing plants, and flowering plants. Seeds Water-conducting (vascular) tissue Green algae ancestor Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 22–1 Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 22–1 Most plants alive today are cone-bearing. flowering. ferns. mosses. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 22–1 The two phases of a plant's life cycle are referred to as alternation of generations. spontaneous generation. biogenesis. sexual and asexual. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 22–1 Which statement accurately describes a way that plants meet their basic needs? Plants take in carbon dioxide from soil through their roots. Plants obtain the energy for photosynthesis from sunlight. Plants obtain minerals by exchanging gases with the atmosphere. Plants absorb water through their broad, flat leaves. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 22–1 The first group of plants to evolve from green algae were the cone-bearing plants. ferns. mosses. flowering plants. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall 22–1 The diploid phase of the plant life cycle is known as the sporophyte. gametophyte. egg. spore. Copyright Pearson Prentice Hall
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