Chapter Introduction Lesson 1 Plant Diversity Lesson 2 Plant Reproduction Lesson 3 Plant Processes Chapter Wrap-Up What structures help ensure the survival of plants, and what is the function of each? What do you think? Before you begin, decide if you agree or disagree with each of these statements. As you view this presentation, see if you change your mind about any of the statements. Do you agree or disagree? 1. Humans could survive without plants. 2. Plant cells contain the same organelles as animal cells. 3. Plants can reproduce both sexually and asexually. 4. All plants have a two-stage life cycle. Do you agree or disagree? 5. Plants respond to their environments. 6. Because plants make their own food, they do not carry on cellular respiration. Plant Diversity • How do a plant’s structures ensure its survival? • How are the different plant types alike and different? Plant Diversity • rhizoid • vascular plant • stoma • gymnosperm • nonvascular plant • angiosperm What is a plant? • A plant is a multicellular organism which is capable of producing its own food using energy from the Sun. • Like all other organisms, plants are made up of cells. Digital Vision/Getty Images What is a plant? (cont.) • A plant cell contains chloroplasts, which are organelles that make food. • Unlike an animal cell, a rigid cell wall surrounds a plant cell and helps protect and support it. • A plant cell also contains a large central vacuole. What is a plant? (cont.) • Most plants have roots, stems, and leaves. • Roots anchor a plant in the soil, enable it to grow upright, and absorb water and minerals from the soil. What is a plant? (cont.) • Some plants, such as mosses and hornworts, have rootlike structures called rhizoids. • Rhizoids are structures that anchor a plant but do not transport water and minerals. What is a plant? (cont.) • Stems help support the leaves and flowers and have tissues that help carry water and minerals to a plant’s leaves. • The two main types of stems are woody stems and herbaceous stems. What is a plant? (cont.) In most plants, leaves are the major sites for photosynthesis. What is a plant? (cont.) • Water vapor, carbon dioxide, and oxygen can pass into and out of a leaf through stomata. Dr. Gerald Van Dyke/Visuals Unlimited/Getty Images • The stomata are small openings in the surfaces of most plant leaves. What is a plant? (cont.) How do plant structures such as roots, stems, and leaves ensure a plant’s survival? Nonvascular Plants • Plants that lack specialized tissues for transporting water and nutrients are nonvascular plants. • The divisions of nonvascular plants include mosses, liverworts, and hornworts. Vascular Seedless Plants • Vascular plants have specialized tissues, called vascular tissues, that transport water and nutrients throughout the plant. • Vascular seedless plants include ferns, horsetails, and club mosses. Vascular Seed Plants • Scientists organize vascular seed plants into two groups—those that produce flowers and those that do not. • Gymnosperms are plants that produce seeds that are not part of a fruit. Vascular Seed Plants (cont.) gymnosperm from French gymnosperme, means “naked seed” Vascular Seed Plants (cont.) • The most common gymnosperms are conifers. • Conifers are usually evergreen, meaning they stay green all year. • They have needlelike or scalelike leaves and most produce cones. Siede Preis/Getty Images What is a plant? (cont.) How are the different plant types alike and different? • Unlike animal cells, a plant cell has a rigid cell wall, chloroplasts, and a large central vacuole. • Plants have structures that help ensure their survival. • Vascular plants have specialized tissues for transporting water and nutrients. What part of a plant anchors to the terrain, enabling it to grow upright and absorb water and minerals? A. leaves B. roots C. stems D. stomata What type of plants lack specialized tissues for transporting water and nutrients? A. club mosses B. nonvascular plants C. rhizoids D. vascular plants What are the small openings on the surfaces of most plant leaves? A. rhizoids B. roots C. stems D. stomata Do you agree or disagree? 1. Humans could survive without plants. 2. Plant cells contain the same organelles as animal cells. Plant Reproduction • How do asexual and sexual reproduction in plants compare and contrast? • What are the differences between the life cycles of seedless and seed plants? Plant Reproduction • pollination • dormancy • pistil • stamen Asexual Reproduction • Asexual reproduction occurs when only one parent organism or part of that organism produces a new organism. • The new organism is genetically identical to the parent. Sexual Reproduction • During sexual reproduction, fertilization occurs when a sperm and an egg join, combining their genetic material. • Sexual reproduction produces individuals that have a different genetic makeup than the parent organism or organisms. • Both seedless plants and seed plants can reproduce sexually. Sexual Reproduction (cont.) How do asexual and sexual reproduction in plants compare and contrast? Plant Life Cycles • The two stages in the life cycle of every plant are the gametophyte stage and the sporophyte stage. • The gametophyte stage begins with a spore, or haploid cell. • Through mitosis and cell division, the spore produces a plant structure or an entire plant called a gametophyte. Plant Life Cycles (cont.) • When a male and a female sex cell combine, fertilization occurs and a diploid cell forms. • That diploid cell is the beginning of the sporophyte stage. • This cell divides through mitosis and cell division and forms the sporophyte. In seedless plants, spores are produced by the sporophyte. Plant Life Cycles (cont.) • Seed plants produce pollen grains, which contain sperm, and female structures, which contain one or more eggs. • The process that occurs when pollen grains land on a female plant structure of a plant of the same species is pollination. • If a sperm from a pollen grain joins with an egg, this is called fertilization. Plant Life Cycles (cont.) • The embryo is the beginning of the sporophyte stage of seed plants. • The embryo and its food supply are enclosed within a protective coat, forming a seed. • In most seed plants, the seed will go through dormancy, which is a period of no growth. Plant Life Cycles (cont.) • Most flowers have four main structures: petals, sepals, pistil, and stamen. • The petals might be brightly colored to attract insect or animal pollinators. • The sepals are usually located beneath the petals and help protect the flower when it is a bud. Plant Life Cycles (cont.) • The female reproductive organ of a flower is the pistil. • The stamen is the male reproductive organ of a flower. Plant Life Cycles (cont.) pistil from French pistil, means “female organ of a flower” The life cycle of a flowering plant includes both gametophyte and sporophyte stages. Plant Life Cycles (cont.) What are the differences between life cycles of seedless and seed plants? Plant Life Cycles (cont.) • Plants that grow from a seed and produce flowers in one growing season are called annuals. • Plants that take two growing seasons to produce flowers are known as biennials. • Perennials are plants that grow and bud for many years. • There are two stages in the life cycle of every plant—the gametophyte stage and the sporophyte stage. • Annuals, biennials, and perennials are the different growth cycles of plants. • Most seed plants produce flowers. What type of reproduction produces individuals that have a different genetic makeup than the parent organism or organisms? A. B. C. D. asexual reproduction fertilization pollination sexual reproduction What is a period of no growth for the seed of most seed plants? A. asexual reproduction B. dormancy C. fertilization D. pollination What type of plant takes two growing seasons to produce flowers? A. annual B. biennial C. perennial D. pistil Do you agree or disagree? 3. Plants can reproduce both sexually and asexually. 4. All plants have a two-stage life cycle. Plant Processes • What is the relationship between photosynthesis and cellular respiration? • How do water and minerals move in vascular and nonvascular plants? • How do plants respond to environmental changes? Plant Processes • transpiration • stimulus • tropism Photosynthesis and Cellular Respiration • Plants absorb light energy from the Sun and convert it into chemical energy in a process called photosynthesis. • During photosynthesis, a plant produces sugar that it uses as food. • Cellular respiration is the process of releasing energy by breaking down food. Photosynthesis and Cellular Respiration (cont.) What is the relationship between photosynthesis and celllular respiration? Photosynthesis and Cellular Respiration (cont.) • Photosynthesis occurs inside organelles called chloroplasts. • Chloroplasts contain chlorophyll, a green pigment that absorbs light energy. • That energy splits apart water molecules into hydrogen atoms and oxygen atoms. Photosynthesis and Cellular Respiration (cont.) • Some of the oxygen leaves the plant through the stomata. • Carbon dioxide combines with the hydrogen atoms and forms glucose, a type of sugar. • A plant can store sugars, and it uses some of the oxygen in another process called cellular respiration. Photosynthesis and Cellular Respiration (cont.) Photosynthesis can be shown by the following equation: Photosynthesis and Cellular Respiration (cont.) • The process of cellular respiration breaks down the glucose produced during photosynthesis and releases the sugar’s energy. • Cellular respiration occurs in the cytoplasm and mitochondria. Photosynthesis and Cellular Respiration (cont.) The equation for cellular respiration is as follows: Photosynthesis and Cellular Respiration (cont.) • Cellular processes such as growth, repair, and reproduction all use ATP. • Plants and some other organisms can use the waste products of cellular respiration—carbon dioxide and water— to make more glucose through photosynthesis. Movement of Nutrients and Water • In order to carry on photosynthesis and cellular respiration, water and nutrients must move inside plants. • This movement or transport of materials occurs through diffusion and osmosis in nonvascular plants. • In vascular plants, water and nutrients move inside specialized vascular tissues. Movement of Nutrients and Water (cont.) • Roots of plants absorb water and nutrients from the soil. • Nutrients from the soil, such as minerals, are used for making many of the compounds needed for cell growth and maintenance. Movement of Nutrients and Water (cont.) Transpiration is the release of water vapor from stomata in leaves. Movement of Nutrients and Water (cont.) How do water and nutrients move in a nonvascular plant? In a vascular plant? Plant Responses • Stimuli are any changes in an organism’s environment that cause a response. • External stimuli include light, touch, and gravity. • Internal stimuli, called hormones, are produced inside a plant and can affect growth, seed germination, or fruit ripening. Plant Responses (cont.) • Plant growth toward or away from an external stimulus is called tropism. • When a plant grows toward a light source, it is called positive phototropism. • A plant’s response to gravity is called gravitropism. • A plant’s response to touch is called thigmotropism. Plant Responses (cont.) tropism from Greek tropos, means “a turn, change” Plant Responses (cont.) How do plants respond to environmental changes? • Plants make sugar through the process of photosynthesis. Plants break down sugar into usable energy through the process of cellular respiration. • All plants must be able to transport water and minerals in order to survive. • Plants respond to internal and external stimuli. What process breaks down glucose and releases sugar’s energy? A. cellular respiration B. photosynthesis C. pollination D. transpiration What term describes stimuli that includes light, touch, and gravity? A. external stimuli B. internal stimuli C. transpiration D. tropism Which term refers to a plant’s response to touch? A. gravitropism B. photosynthesis C. phototropism D. thigmotropism Do you agree or disagree? 5. Plants respond to their environments. 6. Because plants make their own food, they do not carry on cellular respiration. Key Concept Summary Interactive Concept Map Chapter Review Standardized Test Practice There are many different types of plants, but they all have structures and functions that help ensure survival. Lesson 1: Plant Diversity • Roots and rhizoids anchor plants. Roots are found on vascular plants and are able to absorb water and nutrients. Rhizoids are found on nonvascular plants and do not absorb water and nutrients. Stems help support the leaves, and in some cases flowers, of a plant. Stems help carry water and nutrients throughout the plant. In most plants, leaves are the major sites for photosynthesis. In addition to making food, leaves also are involved in the exchange of gases with the environment through the stomata. • Plants are classified into groups called divisions. The main divisions are nonvascular plants and vascular plants. Lesson 2: Plant Reproduction • Asexual reproduction does not involve sex cells. Offspring are genetically identical to the parent. Sexual reproduction involves sex cells and produces offspring that are not genetically identical to each other or the parent plant(s). • The life cycles of seedless and seed plants both contain a gametophyte and a sporophyte stage. Seed plants produce seeds, and seedless plants produce spores. Lesson 3: Plant Processes • Plants produce sugar through photosynthesis. Cellular respiration is the process by which organisms break down the sugar into smaller high energy molecules, or ATP. ATP is used for life processes. • Water and nutrients move by osmosis and diffusion in nonvascular plants. These substances are transported through vascular tissue in vascular plants. • Plants respond to stimuli in their environment. Growth toward or away from a stimulus is called a tropism. What are structures that anchor a plant without transport tissue to a surface? A. pistils B. rhizoids C. seeds D. stomata Which plant part is the major site for photosynthesis? A. stomata B. stems C. roots D. leaves What occurs when pollen grains land on a female plant structure of a plant in the same species? A. dormancy B. fertilization C. pollination D. transpiration Which term refers to the female reproductive organ of a flower? A. petal B. pistil C. sepal D. stamen Which term refers to the release of water vapor from stomata in leaves? A. tropism B. transpiration C. photosynthesis D. cellular respiration What has specialized tissues that transport water and nutrients throughout a plant? A. liverworts B. mosses C. nonvascular plants D. vascular plants Which term describes plants that produce seeds that are not part of a fruit? A. club mosses B. gymnosperms C. rhizoids D. stomata What is the beginning of the sporophyte stage of seed plants? A. sperm B. pistil C. embryo D. egg What plants grow from a seed and produce flowers in one growing season? A. stamen B. pistil C. perennials D. annuals Which describes any changes in an organism’s environment that cause a response? A. photosynthesis B. stimuli C. transpiration D. tropism