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Resources Chapter Presentation Visual Concepts Transparencies Standardized Test Prep

The Importance of Plants Chapter 27 Table of Contents Section 1 Plants and People Section 2 Plants and the Environment

Section 1 Plants and People Chapter 27 Objectives • Summarizethe history of plant cultivation. • Identifythe categories of food crops. • Explainhow humans have increased food production in the world. • Describenon-food uses of plants.

Section 1 Plants and People Chapter 27 Plant Cultivation • The study of plants is calledbotany. • The practical applications of botany are evident inagriculture,which is the raising of crops and livestock for food or other uses. • Humans have cultivated plants for approximately 11,000 years and have changed, by selection, many plant species so much that these plants can no longer survive in the wild.

Section 1 Plants and People Chapter 27 Early Cultivated Plants

Section 1 Plants and People Chapter 27 Food Crops • Food crops can be classified in many ways, including by their use and by their taxonomic classification.

Section 1 Plants and People Chapter 27 Food Crops, continued Cereals • The major part of the human diet is provided by a few cereal crops in the grass family, especially corn, wheat, and rice.

Section 1 Plants and People Chapter 27 Food Crops, continued Root Crops • Root crops are roots or underground stems that are rich in carbohydrates. • In many parts of the world, root crops, such as potatoes and cassava, substitute for cereals in providing the major part of the diet.

Section 1 Plants and People Chapter 27 Food Crops, continued Legumes • Legumes,such as clover and alfalfa, are members of the pea family and bear seeds in pods.

Section 1 Plants and People Chapter 27 Food Crops, continued Fruits, Vegetables, and Nuts • Everyday definitions of fruits and vegetables are different from botanical definitions. • Botanically speaking, a fruit is the part of a flowering plant that usually contains seeds. • A vegetable is derived from the leaves, stems, seeds, and roots of nonwoody plants. • A nut is a dry, hard fruit that does not split open to release its seed.

Section 1 Plants and People Chapter 27 Food Crops, continued Spices, Herbs, and Flavorings • Other food crops add variety and pleasure to our diet by flavoring our water, beverages, and food. • Both spices and herbs are used to add taste to food.

Section 1 Plants and People Chapter 27 Food Crops, continued Food Production • Several factors have increased food production, including the use offertilizersandpesticides. • As land is cultivated to produce an adequate food supply, the health of the environment is compromised by soil erosion, depleted water supplies, and pollution.

Section 1 Plants and People Chapter 27 Major Crop-Producing Regions of the World

Section 1 Plants and People Chapter 27 Parts of Plants Eaten as Food

Section 1 Plants and People Chapter 27 Nonfood Uses of Plants Medicines • Plants provide many important medicines, such as digitalis, quinine, morphine, and anti-cancer drugs.

Section 1 Plants and People Chapter 27 Medicines Originally Derived from Plants

Section 1 Plants and People Chapter 27 Nonfood Uses of Plants, continued • Plants provide thousands of nonfood products, including clothing, fabric dye, lumber, paper, cosmetics, fuel, cork, rubber, turpentine, and pesticides.

Section 1 Plants and People Chapter 27 Nonfood Uses of Plants, continued Other Uses of Plants • Ornamental plants improve the human environment in many important ways: they provide shade, minimize soil erosion, reduce noise, and lower home energy costs.

Section 2 Plants and the Environment Chapter 27 Objectives • Summarizethe contributions of plants to the environment. • Describethe ways that plants interact with other organisms. • Explainhow some plants can cause harm.

Section 2 Plants and the Environment Chapter 27 Plant Ecology • Plant ecologyis the study of the interactions between plants and the environment. • Plants play a major role in recycling the Earth’s water, oxygen, carbon dioxide, and inorganic nutrients.

Section 2 Plants and the Environment Chapter 27 Plant Ecology, continued Plant-Animal Interactions • Plants provide animals with inorganic nutrients as well as organic nutrients. • Plants associate with animals in many mutually beneficial ways. For example, plants provide food to animals that protect them or carry their pollen.

Section 2 Plants and the Environment Chapter 27 Plant Ecology, continued Plant-Microbe Interactions • Most plant roots are penetrated by beneficialmycorrhizalfungi, which greatly increase the roots’ ability to absorb inorganic nutrients. In return, the root supplies the fungus with energy. • The roots of many plant species also form beneficial associations with bacteria. Some bacteria can take nitrogen gas from the air and convert it into a form that plants can use.

Section 2 Plants and the Environment Chapter 27 Plant Ecology, continued Plant-Human Interactions • People have affected wild plant populations negatively by introducing foreign species of plants, animals, and disease organisms.

Section 2 Plants and the Environment Chapter 27 Harmful Plants • Many deaths are caused by addictive plant products. • Some plant species are poisonous when eaten or touched. • Millions of people suffer from allergies to pollen.

Chapter 27 Standardized Test Prep Multiple Choice 1. Early farmers selected wheat plants that had which of the following characteristics? A. fewest grains B. largest seed pods C. easily dispersed seeds D. stalks not easily broken in the wind

Chapter 27 Standardized Test Prep Multiple Choice, continued 2. Which plants are the major source of food for the world today? F. spices G. cereals H. legumes J. root crops

Chapter 27 Standardized Test Prep Multiple Choice 3. Which of the following is an inorganic nutrient recycled by plants? A. sugar B. starch C. cellulose D. phosphorus

Chapter 27 Standardized Test Prep Multiple Choice, continued The illustration below shows four types of food plants. Use the illustration to answer the question that follows.

Chapter 27 Standardized Test Prep Multiple Choice, continued 4. Plants classified as root cops have edible underground structures. which of the food plants shown above is a root crop? F. rice G. pecan H. potato J. oregano

Chapter 27 Standardized Test Prep Multiple Choice 5. vegetable : root crop :: grain : A. herb B. spice C. cereal D. quinine

Chapter 27 Standardized Test Prep Multiple Choice, continued The illustration below shows how plants might be grown together. Use the illustration to answer the question that follows.

Chapter 27 Standardized Test Prep Multiple Choice, continued 6. How does this arrangement help these plants? F. The squash can use the corn as a support. G. The beans grow apart from the squash and corn. H. The corn covers the ground and reduces erosion. J. Beans, which are legumes, will provide nitrogen fertilizer for the corn and squash.

Chapter 27 Standardized Test Prep Short Response Look again at the illustration of the corn, beans and squash. Explain the advantage to the human diet of growing and eating these food crops together.

Chapter 27 Standardized Test Prep Short Response, continued Look again at the illustration of the corn, beans and squash. Explain the advantage to the human diet of growing and eating these food crops together. Answer: Eating a variety of foods can help provide a more complete and balanced diet. Beans and corn together provide a complete set of amino acids.

Chapter 27 Standardized Test Prep Extended Response Base your answers to parts A & B on the information below. Plants have been cultivated for at least 11,000 years. Part A Identify 5 plants people use for food and 5 plants people use for other purposes. Part B How has human cultivation changed some plants?

Chapter 27 Standardized Test Prep Extended Response, continued Answer: Part A Examples of food plants could include wheat, potato, soybean, apple, and lettuce. Nonfood plants include white willow, cinchona, foxglove, yam, and yew. Part BHumans have acted like selection agents, and this has led to plants with more desirable traits, such as disease resistance.

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