Lesson 1 Energy Processing in Plants Chapter Introduction Lesson 1 Energy Processing in Plants Lesson 2 Plant Responses Chapter Wrap-Up Chapter Menu

What processes enable plants to survive? Chapter Introduction

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. Chapter Introduction

Do you agree or disagree? 1. Plants do not carry on cellular respiration. 2. Plants are the only organisms that carry on photosynthesis. 3. Plants make food in their underground roots. Chapter Introduction

Do you agree or disagree? 4. Plants do not produce hormones. 5. Plants can respond to their environments. 6. All plants flower when nights are 10–12 hours long. Chapter Introduction

Lesson 1 Reading Guide - KC Energy Processing in Plants How do materials move inside plants? How do plants perform photosynthesis? What is cellular respiration? How are photosynthesis and cellular respiration alike, and how are they different? Lesson 1 Reading Guide - KC

Lesson 1 Reading Guide - Vocab Energy Processing in Plants photosynthesis cellular respiration Lesson 1 Reading Guide - Vocab

Like people, plants need food, water, and oxygen to survive. The roots of a plant absorb water, which travels inside xylem cells to all parts of a plant. Most plants make their own food-a liquid called sugar, which flows to all plant cells. Plants require oxygen and carbon dioxide to make food.

Photosynthesis is a series of chemical reactions that convert light energy, water, and carbon dioxide into the food-energy molecule glucose and give off oxygen. Leaves are the major food-producing organs of plants. The cells that make up the top and bottom layers of a leaf are flat, irregularly shaped cells called epidermal cells.

On the bottom epidermal later of leaves are small opening called stomata. Mesophyll cells contain the organelle where photosynthesis occurs, the chloroplast. In the first step of photosynthesis, plants capture the energy in light.

Plant Structure

Materials for Plant Processes (cont.) Carbon dioxide, oxygen, and water vapor pass into and out of a plant through tiny openings in leaves. How do materials move through plants? Lesson 1-1

Photosynthesis Photosynthesis is a series of chemical reactions that convert light energy, water, and carbon dioxide into the food-energy molecule glucose and give off oxygen. photosynthesis from Greek photo–, means “light”; and synthesis, means “composition” Lesson 1-2

Lesson 1-2

Photosynthesis (cont.) This occurs in chloroplasts, which contain plant pigments. Chlorophyll, the most common plant pigment, is necessary for photosynthesis. Chlorophyll reflects green light, absorbs other colors of light, and uses this energy for photosynthesis. Lesson 1-2

Lesson 1-2

During photosynthesis, water molecules are split apart, releasing oxygen into the atmosphere.

Photosynthesis (cont.) Sugars are made in the second step of photosynthesis. In chloroplasts, carbon dioxide and water are broken down and, using energy stored in chlorophyll, form sugar molecules. Lesson 1-2

Photosynthesis is important because it produces most of the oxygen in the atmosphere.

Photosynthesis (cont.) What are the two steps of photosynthesis? Lesson 1-2

Cellular Respiration Cellular respiration is a series of chemical reactions that convert the energy in food molecules into a usable form of energy called ATP. Glucose molecules break down during cellular respiration. Plants produce sugar, but without cellular respiration, plants could not grow, reproduce, or repair tissues. Lesson 1-3

Cellular Respiration (cont.) What is cellular respiration? Lesson 1-3

Cellular Respiration (cont.) Most plants, some protists, and some bacteria carry on photosynthesis. Most organisms carry on cellular respiration. Lesson 1-3

Cellular respiration requires the reactants glucose and oxygen, produces carbon dioxide and water, and releases energy in the form of ATP. Life on Earth depends on a balance of photosynthesis and cellular respiration..

Lesson 1-3

Lesson 1-4

Cellular Respiration (cont.) How are photosynthesis and cellular respiration alike, and how are they different? Lesson 1-4

Materials that a plant requires to survive move through the plant in the vascular tissue, xylem and phloem. Plants can make their own food by using light energy, water, and carbon dioxide. Lesson 1 - VS

The products of photosynthesis are the reactants for cellular respiration. Lesson 1 - VS

Which term refers to the organelles where photosynthesis occurs? A. palisade mesophyll cells B. chlorophyll C. chloroplasts D. spongy mesophyll cells Lesson 1 – LR1

Which process breaks down glucose molecules? A. cellular respiration B. light energy capture C. first step of photosynthesis D. second step of photosynthesis Lesson 1 – LR2

Which have open spaces between them that gases flow through? A. spongy mesophyll cells B. palisade mesophyll cells C. chloroplasts D. chlorophyll Lesson 1 – LR3

1. Plants do not carry on cellular respiration. Do you agree or disagree? 1. Plants do not carry on cellular respiration. 2. Plants are the only organisms that carry on photosynthesis. 3. Plants make food in their underground roots. Lesson 1 - Now

Lesson 2 Reading Guide - KC Plant Responses How do plants respond to environmental stimuli? How do plants respond to chemical stimuli? Lesson 2 Reading Guide - KC

Lesson 2 Reading Guide - Vocab Plant Responses stimulus tropism photoperiodism plant hormone Lesson 2 Reading Guide - Vocab

Stimuli and Plant Responses Stimuli are any changes in an organism’s environment that cause a response. A plant responds to light by growing toward it. When stimulated by an insect’s touch, the two sides of a Venus flytrap snap shut immediately, trapping the insect inside. Lesson 2-1

Plants responses to different environmental stimuli include light, touch, and gravity.

Environmental Stimuli A tropism is a response that results in plant growth toward or away from a stimulus. When the growth is toward a stimulus, the tropism is called positive. Growth away from a stimulus is considered negative. Lesson 2-2

The growth of a plant toward or away from light is a tropism called phototropism Lesson 2-2

Leaves and stems tend to grow in the direction of light. Roots generally grow away from light.

Environmental Stimuli (cont.) tropism from Greek tropos, means “turn” or “turning” Lesson 2-2

Environmental Stimuli (cont.) The response of a plant to touch is called a thigmotropism. Special structures that respond to touch, called tendrils, can wrap around or cling to objects. When touched, the leaves of Mimosa pudica quickly droop or fold up. Lesson 2-2

Environmental Stimuli (cont.) The response of a plant to gravity is called gravitropism. Stems grow away from gravity, while roots grow toward gravity. Lesson 2-2

Environmental Stimuli (cont.) What types of environmental stimuli do plants respond to? Give three examples. Lesson 2-2

Environmental Stimuli (cont.) Some plants flower in response to the amout of darkness they are exposed to. Photoperiodism is a plant’s response to the number of hours of darkness in its environment. Plants that flower when exposed to less than 10-12 hours of darkness are called long-day plants. Lesson 2-2

Environmental Stimuli (cont.) Short-day plants require 12 or more hours of darkness for flowering to begin. Day-neutral plants flower when they reach maturity and the environmental conditions are right. Lesson 2-2

The number of hours of darkness controls flowering in many plants. Lesson 2-2

Plant hormones are substances that act as chemical messengers within plants. Hormones are called messengers because they are usually produced at one part of a plant and affect another part of the plant.

Chemical Stimuli Auxins are hormones responsible for phototropism and cause increased plant growth. They cause the cells on the dark side of the plant’s stem to grow longer. Lesson 2-3

Chemical Stimuli (cont.) The plant hormone ethylene helps stimulate the ripening of fruit. Ethylene is a gas that can be produced by fruits, seeds, flowers, and leaves. How do plants respond to the chemical stimuli, or hormones, auxin and ethylene? Lesson 2-3

Chemical Stimuli (cont.) Rapidly growing areas of a plant, such as roots and stems, produce gibberellins, which increase the rate of cell division and cell elongation. Root tips produce cytokinins, a hormone that increases the rate of cell division and, in some plants, slows the aging process of flowers and fruits. Lesson 2-3

Plants produce many different hormones. Often, two or more plant hormones interact and produce a plant response.

Humans and Plant Responses Humans make plants more productive by using plant hormones. Some crops now are easier to grow because humans understand how plants respond to hormones. Lesson 2-4

Plants respond to stimuli in their environments in many ways. Lesson 2 - VS

Photoperiodism occurs in long-day plants and short-day plants Photoperiodism occurs in long-day plants and short-day plants. Day- neutral plants are not affected by the number of hours of darkness. Lesson 2 - VS

Plant hormones are internal chemical stimuli that produce different responses in plants. Lesson 2 - VS

Which term refers to the growth of a plant toward or away from light? A. phototropism B. photoperiodism C. gravitropism D. thigmotropism Lesson 2 – LR1

Which of the following helps stimulate the ripening of fruit? A. auxins B. cytokinins C. ethylene D. tendrils Lesson 2 – LR2

Which refers to special plant structures that respond to touch? A. roots B. stems C. leaves D. tendrils Lesson 2 – LR3

4. Plants do not produce hormones. Do you agree or disagree? 4. Plants do not produce hormones. 5. Plants can respond to their environments. 6. All plants flower when nights are 10–12 hours long. Lesson 2 - Now

Interactive Concept Map Chapter Review Standardized Test Practice Key Concept Summary Interactive Concept Map Chapter Review Standardized Test Practice Chapter Review Menu

Plants survive by maintaining homeostasis and responding to stimuli Plants survive by maintaining homeostasis and responding to stimuli. In addition, they acquire the energy they need for life processes through photosynthesis and cellular respiration. The BIG Idea

Lesson 1: Energy Processing in Plants The vascular tissues in most plants, xylem and phloem, move materials throughout plants. In photosynthesis, plants convert light energy, water, and carbon dioxide into the food-energy molecule glucose through a series of chemical reactions. The process gives off oxygen. Cellular respiration is a series of chemical reactions that convert the energy in food molecules into a usable form of energy called ATP. Photosynthesis and cellular respiration can be considered opposite processes of each other. Key Concepts 1

Lesson 2: Plant Responses Although plants cannot move from one place to another, they do respond to stimuli, or changes in their environments. Plants respond to stimuli in different ways. Tropisms are growth responses toward or away from stimuli such as light, touch, and gravity. Photoperiodism is a plant’s response to the number of hours of darkness in its environment. Plants respond to chemical stimuli, or plant hormones, such as auxins, ethylene, gibberellins, and cytokinins. Different hormones have different effects on plants. Key Concepts 2

Carbon dioxide, oxygen, and water vapor pass into and out of a plant through which part of a plant? A. leaves B. phloem C. roots D. xylem Chapter Review – MC1

Water flows to all parts of a plant in which of these? A. xylem B. phloem C. chloroplasts D. chlorophyll Chapter Review – MC2

Which term refers to a response that results in plant growth toward or away from a stimulus? A. photoperiodism B. photosynthesis C. stimuli D. tropism Chapter Review – MC3

When the growth is toward a stimulus, what is the tropism referred to as? A. negative B. photoperiodism C. photosynthesis D. positive Chapter Review – MC4

Which acts as chemical messengers in plants? A. hormones B. stoma C. tendrils D. xylem Chapter Review – MC5

A. cellular respiration B. photosynthesis C. xylem D. phloem Which term refers to a series of chemical reactions that convert light energy, water, and carbon dioxide into the food-energy molecule glucose? A. cellular respiration B. photosynthesis C. xylem D. phloem Chapter Review – STP1

Where does the first step of photosynthesis occur? A. xylem B. phloem C. mesophyll cells D. chloroplasts Chapter Review – STP2

Which term describes any changes in an organism’s environment that cause a response? A. tropism B. gravitropism C. phototropism D. stimuli Chapter Review – STP3

Short-day plants require how many hours of darkness for flowering to begin? A. 12 or more B. 10 to 12 C. 8 to 10 D. less than 8 Chapter Review – STP4

A growing ivy plant comes into contact with a brick building and begins to grow up the building. What is this response? A. gravitropism B. photoperiodism C. phototropism D. thigmotropism Chapter Review – STP5