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

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Plant? Chapter 12 Identify four characteristics that all plants share. Describe the four main groups of plants. Explain the origin of plants. Objectives

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Plant? Chapter 12 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 *.

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Plant? Chapter 12 Plant Characteristics, continued Cell Walls * Reproduction Plants have two stages in their life cycle— *

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Plant? Chapter 12 ?

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Plant? Chapter 12 Plant Classification Nonvascular Plants A nonvascular plant is * Vascular Plants * is called a vascular plants.

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Plant? Chapter 12 ?

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 What Is a Plant? Chapter 12 The Origin of Plants Plants Are Cousins of Green Algae Because they exhibit many similarities, scientists think that green algae and plants share a common ancestor.

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Seedless Plants Chapter 12 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. Objectives

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Seedless Plants Chapter 12 Nonvascular Plants Mosses Mosses often live together in large groups. They cover soil or rocks with a mat of tiny green plants. Mosses have leafy stalks and rhizoids. A rhizoid is a *

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Seedless Plants Chapter 12 Nonvascular Plants, continued Ferns Ferns grow in many places, from the cold arctic to humid tropical forests. Most ferns have a rhizome. A rhizome *

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Seedless Plants Chapter 12 Nonvascular Plants, continued Liverworts and Hornworts Like mosses, liverworts and hornworts are usually small, nonvascular 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.

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Seedless Plants Chapter 12

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Seedless Plants Chapter 12 Seedless Vascular Plants, continued The Importance of Seedless Vascular Plants Ferns, horsetails, and club mosses help form soil. They also help prevent soil erosion. Some ferns and horsetails can be eaten. Horsetails are used in dietary supplements, shampoos, and skin-care products.

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Seedless Plants Chapter 12 Seedless Vascular Plants, continued The remains of ferns, horsetails, and club mosses that lived and died 300 million years ago formed coal. Humans rely on coal for energy.

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 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.. Objectives

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 Characteristics of Seed Plants Seed plants differ from seedless plants in the following ways: *. * *

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 The Structure of Seeds 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.

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 The Structure of a Seed

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 Gymnosperms, continued The Importance of Gymnosperms Conifers are the most economically important gymnosperms. People use conifer wood for building materials and paper products. Resin, *

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 Gymnosperms, continued 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. Pollination is the transfer of *

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 Angiosperms Angiosperms are * Angiosperm Reproduction Flowers help angiosperms reproduce. Flowers attract animals that help spread pollen. Fruits surround and protect the seeds.These fruits help angiosperms distribute their seeds.

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 Angiosperms, continued Two Kinds of Angiosperms Angiosperms are divided into two classes— monocots and dicots. The next slide shows the two kinds of angiosperms.

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Seed Plants Chapter 12 Angiosperms, continued 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. Flowering plants are used to make cloth fibers, rope, medicines, rubber, perfume oil, and building materials.

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 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. Objectives

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 There are two types of vascular tissue in plants: Xylem is * Phloem is *

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Roots Root Functions The following are the main functions of roots: Roots *

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Roots, continued Root Structure * is called the epidermis. After water and minerals are absorbed by the epidermis, they diffuse into the center of the root where the vascular tissue is located. A root cap can be found at the end of the root. The root cap *

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Roots, continued Root Systems There are two kinds of root systems— *. Taproot systems have a main root, or tap root, that grows downward. Dicots and gymnosperms usually have tap root systems. Fibrous systems have several roots that spread out from the base of the stem. Monocots usually have fibrous root systems.

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Stems Stem Functions A stem connects a plant’s roots to its leaves and flowers. A stem also has the following functions: Stems * Some stems *

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Stems, continued 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.

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Stems, continued Woody Stems Trees and shrubs have rigid stems made of wood and bark. These stems are called woody stems.

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 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.

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Leaves, continued Leaf Adaptations Some leaves have functions other than photosynthesis. The leaves of many cactuses are modified as spines. These spines keep animals from eating the cactuses. The leaves of sundews are modified to catch insects, which the sundew digests.

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Flowers Flowers are adaptations for sexual reproduction. Sepals and Petals *are called sepals. Petals are *

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Flowers, continued Stamens and Pistils The male reproductive structure of a flower is called a stamen. A Pistil *

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Structures of Seed Plants Chapter 12 Flowers, continued The Importance of Flowers Flowers help plants reproduce. Humans use flowers for arrangement. Flowers are also used to make spices, perfumes, and lotions. Broccoli, cauliflower, and artichokes are flowers that people eat. Chamomile and hibiscus flowers are used to make tea.