1. How to Use This Presentation To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show”, or simply press F5 on the top row of your keyboard. To advance to the next slide click the left mouse button once. From the Chapter screen you can click on any section to go directly to that section’s presentation. Blank or “missing” areas of a slide will remain hidden until the left mouse button is clicked. You may exit the slide show at any time by pressing the Esc key Copyright © by Holt, Rinehart and Winston. All rights reserved.

2. Introduction to Plants Chapter 12 Section 1: What Is a Plant? Section 2: Seedless Plants Section 3: Seed Plants Section 4: Structures of Seed Plants Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

3. What Is a Plant? Section 1 Bellringer There are four major types of plants. Try to identify all four types, and give at least two examples for each one. Do all the four types of plants grow at your home? Where are you most likely to find each type of plant? Write your responses in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

4. What Is a Plant? Section 1 Objectives Identify four characteristics that all plants share. Describe the four main groups of plants. Explain the origin of plants. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

5. What Is a Plant? Section 1 Plant Characteristics Photosynthesis Plants use energy from sunlight to make food from carbon dioxide and water. This process is called photosynthesis. Cuticles A cuticle is a waxy layer that coats most of the surfaces of plants that are exposed to air. Cell Walls Plant cells are surrounded by a rigid cell wall. Reproduction Plants have two stages in their life cycle— the sporophyte stage and the gametophyte stage. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

6. What Is a Plant? Section 1 Plant Classification Nonvascular Plants A nonvascular plant is a plant that doesn’t have specialized tissues to move water and nutrients through the plant. Vascular Plants A plant that has tissues to deliver water and nutrients from one part of the plant to another is called a vascular plants. The next slide shows the main groups of both vascular and nonvascular plants. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

7. The Main Groups of Plants Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved.

8. What Is a Plant? Section 1 The Origin of Plants Plants Are Cousins of Green Algae Scientists think that green algae and plants share a common ancestor. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

9. Seedless Plants Section 2 Bellringer If plants can make their own food, why do people add fertilizer to soil? What happens when you plant crops in the same field over and over again? Does fertilizer ever stop working? Write your answers in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

10. Seedless Plants Section 2 Objectives List three nonvascular plants and three seedless vascular plants. Explain how seedless plants are important to the environment. Describe the relationship between seedless vascular plants and coal. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

11. Seedless Plants Section 2 Nonvascular Plants Copyright © by Holt, Rinehart and Winston. All rights reserved. Mosses Mosses often live together in large groups. They cover soil or rocks with a mat of tiny green plants. Liverworts and Hornworts Like mosses, liverworts and hornworts are small, non vascular plants that usually live in damp places. The Importance of Nonvascular Plants Nonvascular plants are usually the first plants to live in a new environment, such as newly exposed rock. When these nonvascular plants die, they form a thin layer of soil. End of Slide

12. Seedless Plants Section 2 Seedless Vascular Plants Copyright © by Holt, Rinehart and Winston. All rights reserved. Ferns Most ferns have rhizome. A rhizome is an underground stem from which new leaves and roots grow. Horsetails and Club Mosses Modern horsetails can be as tall as 8 m. But many horsetails are smaller. They usually grow in wet, marshy places. Club mosses are often about 20 cm tall. They grow in woodlands. The Importance of Seedless Vascular Plants Ferns, horsetails, and club mosses help form soil. They also help prevent soil erosion. End of Slide

13. Seed Plants Section 3 Bellringer If plants can make their own food, why do people add fertilizer to soil? What happens when you plant crops in the same field over and over again? Does fertilizer ever stop working? Write your answers in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

14. Seed Plants Section 3 Objectives Describe three ways that seed plants differ from seedless plants. Describe the structure of seeds. Compare angiosperms and gymnosperms. Explain the economic and environmental importance of gymnosperms and angiosperms. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

15. Seed Plants Section 3 Characteristics of Seed Plants Copyright © by Holt, Rinehart and Winston. All rights reserved. Three Unique Traits Seed plants produce seeds. The gametophytes of seed plants do not live independently of the sporophyte. The sperm of seed plants do not need water to reach an egg. Three Parts of a Seed A seed is made up of three parts. The first part is a young plant, or the sporophyte. The second part is stored food. Finally, a seed coat surrounds and protects the young plant. The Structure of Seeds End of Slide

16. Seed Plants Section 3 Gymnosperms Copyright © by Holt, Rinehart and Winston. All rights reserved. The Importance of Gymnosperms Conifers are the most economically important gymnosperms. People use conifer wood for building materials and paper products. Gymnosperm Life Cycle Sperm from pollen in the male cone fertilize the eggs of the female cone. A fertilized egg develops into a young sporophyte within the female cone. End of Slide

17. Seed Plants Section 3 Angiosperms Copyright © by Holt, Rinehart and Winston. All rights reserved. Angiosperm Reproduction Flowers help angiosperms reproduce. Two Kinds of Angiosperms Angiosperms are divided into two classes— monocots and dicots. The next slide shows the two kinds of angiosperms. The Importance of Angiosperms Flowering plants provide many land animals with the food they need to survive. People use flowering plants in many ways. Major food crops, such as corn, wheat, and rice, are flowering plants. Some flowering plants, such as oak trees, are used for building materials. End of Slide

18. Two Classes of Angiosperms Section 3 Copyright © by Holt, Rinehart and Winston. All rights reserved.

19. Structures of Seed Plants Section 4 Bellringer Since plants cannot get up and walk around to disperse their seeds, what kinds of strategies do plants employ to sow their seeds? How do plants protect their seeds from being destroyed or eaten? Explain your answer in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

20. Structures of Seed Plants Section 4 Objectives List three functions of roots and three functions of stems. Describe the structure of a leaf. Identify the parts of a flower and their functions. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

21. Structures of Seed Plants Section 4 Roots Root Functions Roots supply plants with water and dissolved minerals. Roots hold plants securely in the soil. Roots store surplus food made during photosynthesis. Root Structure The structures of a root are shown on the next slide. Root Systems There are two kinds of root systems— taproot systems and fibrous root systems. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

22. The Structures of a Root Section 4 Copyright © by Holt, Rinehart and Winston. All rights reserved.

23. Structures of Seed Plants Section 4 Stems Stem Functions Stems support the plant body. Stems transport materials between the root system and the shoot system. Some stems store materials. Herbaceous Stem Many plants have stems that are soft, thin, and flexible. These stems are called herbaceous stems. A cross section of an herbaceous stem is shown on the next slide. Woody Stems Trees and shrubs have rigid stems made of wood and bark. These stems are called woody stems. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

24. Cross Section of an Herbaceous Stem Section 4 Copyright © by Holt, Rinehart and Winston. All rights reserved.

25. Structures of Seed Plants Section 4 Leaves Leaf Functions The main function of leaves is to make food for the plant. Leaf Structure The structure of leaves, shown on the next slide, is related to their main function— photosynthesis. Leaf Adaptations Some leaves have functions other than photosynthesis. For example, the leaves of many cactuses are modified as spines. These spines keep animals from eating the cactuses. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

26. The Structures of a Leaf Section 4 Copyright © by Holt, Rinehart and Winston. All rights reserved.

27. Structures of Seed Plants Section 4 Flowers Sepals and Petal Sepals are modified leaves that make up the outermost ring of flower parts and protect the bud. Petals are broad, flat, thin leaflike parts of a flower. Stamens and Pistils A stamen is a male reproductive structure of flowers. A pistil is the female reproductive structure of flowers. You can see both these structures on the next slide. The Importance of Flowers Flowers help plants reproduce. Humans also use flowers for many things. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

28. The Structures of a Flower Section 4 Copyright © by Holt, Rinehart and Winston. All rights reserved.

29. Introduction to Plants Chapter 12 Concept Map Copyright © by Holt, Rinehart and Winston. All rights reserved. Use the following terms to complete the concept map on the next slide: angiosperms, vascular, plants, sporophyte, nonvascular, pollen, gametophyte, xylem.

30. Concept Map Chapter 12 Copyright © by Holt, Rinehart and Winston. All rights reserved.

31. Concept Map Chapter 12 Copyright © by Holt, Rinehart and Winston. All rights reserved.