Table of Contents Letter to the Student...................................... 5 Letter to the Family....................................... 6 New York State Performance Standards Correlation Chart....... 7 New York State Core Curriculum Science Skills................ 9 Investigation 1.......................................... 13 Performance Standards Unit 1 Geology..................................... 21 Lesson 1 Earth s Atmosphere................. 22 PS 2.1a,b Lesson 2 Earth s Lithosphere and Hydrosphere... 26 PS 2.1c,d Lesson 3 The Rock Cycle..................... 30 PS 2.2g,h Lesson 4 Minerals and Their Physical Properties.. 35 PS 2.1e Lesson 5 Clues to Earth s Past................ 39 PS 2.1f, PS 2.2d, LE 3.2b,c Lesson 6 Plate Tectonics and Continental Drift.... 45 PS 2.2 a,e PS 3.1i PS 4.2b Lesson 7 Plate Boundaries.................... 50 PS2.2a,c,e,f Lesson 8 Earth s Changing Surface............. 54 PS.2.1g,h,i, PS.2.2a,c Lesson 9 Topography of Earth s Surface......... 59 PS 2.2 a,f Unit 1 Review.............................. 63 Unit 2 Interactions Between Matter and Energy......... 69 Lesson 10 Kinds of Energy and Their Transformations.................... 70 PS 4.1d, PS 4.5a,b Lesson 11 Electromagnetic Energy.............. 76 PS.4.4a Lesson 12 Electricity and Magnetism............ 80 PS 4.4f,g Lesson 13 Light and Vision.................... 86 PS 4.4b Lesson 14 Sound............................ 90 PS.4.4c Lesson 15 Physical Changes................... 94 PS 3.1c,d,e,f, PS3.2a Lesson 16 Physical Properties of Matter.......... 98 PS 3.1a, PS 3.1h Lesson 17 Atoms, Elements, Molecules, Compounds, and Mixtures........... 103 PS 3.3a,c,e,f Lesson 18 Mixtures, Solutions, and Solubility..... 109 PS 3.1b,g, PS 3.2b, PS 3.3b, PS 4.2e Duplicating any part of this book is prohibited by law. 3
New York Coach, Science, Grade 7 Lesson 19 The Periodic Table................. 114 PS 3.2d, PS 3.3g Lesson 20 Chemical Changes in Living Things.... 119 LE 1.2d, LE 5.1c,d, Unit 2 Review............................. 124 LE 5.2c, LE 6.2a,b, PS 3.2c,e, PS 3.3d, PS 4.3e, PS 4.5a,b Unit 3 Dynamic Equilibrium: The Human Organism...... 131 Lesson 21 Cells and Body Organization......... 132 LE 1.1a,b,c,d,e,g, LE 1.2a,b Lesson 22 Respiratory and Circulatory Systems... 138 LE 1.2a,d,f Lesson 23 Digestive and Excretory Systems...... 143 LE 1.2c,e, LE 5.1d, LE 5.2a Lesson 24 Nervous and Endocrine Systems...... 149 LE 1.2a,h, LE 5.1f,g Lesson 25 Nutrition and Metabolism............ 155 LE 1.2h, LE 5.1f, LE 5.2a,b,c,d,e Lesson 26 Muscular and Skeletal Systems....... 160 LE 1.2g Unit 3 Review............................. 164 Unit 4 Dynamic Equilibrium: Other Organisms.......... 169 Lesson 27 How Animals Obtain Nutrients and Energy....................... 170 Lesson 28 Animal Structures and Functions...... 174 LE 1.1g, LE 5.1b Lesson 29 Homeostasis in Animals............. 180 LE 5.1a,f Lesson 30 Animal Responses................. 184 LE 5.1g Lesson 31 Plant Structures and Systems........ 188 LE 1.1f, LE 5.1b Lesson 32 How Plants Obtain Nutrients and Energy....................... 192 LE 5.1c,d,e, LE 5.2a,c LE 5.1c,d, LE 5.2a,b, LE 6.2a Lesson 33 Plant Responses................... 196 LE 5.1a,f,g Lesson 34 Unicellular Organisms............... 200 LE 1.1d,g, Unit 4 Review............................. 205 Investigation 2......................................... 211 Glossary.............................................. 219 LE 5.1c,d,e,f,g, LE 5.2a, LE 6.2a 4 Duplicating any part of this book is prohibited by law.
22 Respiratory and Circulatory Systems LE 1.2a, LE 1.2d,f Getting the Idea Key Words cellular respiration respiratory system lungs alveoli trachea bronchi diaphragm circulatory system heart atrium ventricle arteries veins capillaries plasma red blood cell white blood cell platelet Humans have invented devices such as scuba gear and space suits. These inventions allow people to breathe in even the most difficult environments. But why do people need to breathe? And how is the air that you breathe brought to the cells of your body? Getting the Oxygen You Need Breathing is the process by which humans take in and release air. Air you take inside your body is important because it provides the oxygen your body needs to release energy from your food. Recall that cellular respiration is the process in which our bodies use oxygen to release energy from food to provide energy that the body can use. Air you release from your body contains carbon dioxide, a waste product from cellular respiration. The respiratory system is the body system that is responsible for taking in oxygen and releasing carbon dioxide. It works closely with the circulatory system to carry oxygen to the cells and carbon dioxide away from the cells as waste. The Respiratory System The main organs of the respiratory system are the lungs. The lungs are elastic, sponge-like organs in the chest. The lungs are made up of tiny air sacs called alveoli (sing. alveolus). They are very thin and are surrounded by blood vessels. Oxygen enters the blood through the thin walls of the alveoli. 138 Duplicating any part of this book is prohibited by law.
Lesson 22: Respiratory and Circulatory Systems Did You Know Veins look blue because the blood is dark due to low oxygen levels in the blood in veins. Arteries look red because the blood is bright red due to high oxygen level in the blood in arteries. As you can see on the diagram below, air enters the body through the mouth and nose. From there, it passes down the trachea, or windpipe. The trachea divides into two tubes called bronchi, which enter the lungs. The bronchi divide again and again. Each division ends in an alveolus. Nose Mouth Trachea Lungs Larynx Bronchi Alveoli Diaphragm The respiratory system itself cannot move air into and out of the lungs. Muscles in the chest cause the breathing process, which moves air into and out of the lungs. When you breathe in, or inhale, the diaphragm, a muscle just below the lungs, contracts. This causes the diaphragm to move lower, causing the chest cavity to expand and air to rush into the lungs. Oxygen in the air enters the blood vessels around the alveoli when you breathe in. Carbon dioxide in the blood vessels enters the air in the lungs. When you exhale, the diaphragm relaxes and moves up. This pushes air out of the lungs. Muscles of the abdomen and the ribcage help push the air out. The air you exhale has a higher concentration of carbon dioxide and a lower concentration of oxygen than the air you inhaled. Duplicating any part of this book is prohibited by law. 139
New York Coach, Science, Grade 7 The Circulatory System The circulatory system is a transport system that uses blood to carry food and oxygen to the cells of the body. It also carries waste products like carbon dioxide away from the cells. The circulatory system transports chemical messages from cells in one part of the body to cells in another part, and it distributes substances that help fight disease. The circulatory system is made up of the heart, the blood vessels and the blood. Circulatory System Heart Lungs Veins Arteries The heart is a muscular organ that consists of two pumps working side by side. When the heart muscles contract, they push the blood forward on its path. Each pump involves two chambers: the upper chamber of each side is called the atrium, and the lower chamber is called the ventricle. The left side of the heart receives oxygen-rich blood from the lungs and pumps it to the rest of the body. The right side receives oxygen-poor blood from the rest of the body and pumps it to the lungs. From body To body To lungs To lungs Left atrium From lungs 3 From lungs Right atrium 1 To body 4 2 Left ventricle From body Right ventricle 140 Duplicating any part of this book is prohibited by law.
Lesson 22: Respiratory and Circulatory Systems Blood vessels are the tube-like structures through which the blood flows. There are three types of blood vessels. Arteries carry blood away from the heart. Veins carry blood toward the heart. Capillaries are tiny vessels between arteries and veins that exchange substances such as gases and nutrients between the blood and the body cells. Blood is composed of two main parts: plasma and blood cells. Plasma is a yellowish fluid that is mostly water. It also contains dissolved nutrients, minerals, salts, and gases. The blood cells are the solid components that are floating in the plasma. There are three different types of blood cells. The red blood cells carry oxygen around the body. White blood cells help the body fight disease by attacking invading microorganisms and by producing antibodies to fight infection. Platelets are fragments of cells that help form blood clots to stop bleeding. The circulatory and respiratory systems work together to bring oxygen into the body and deliver it to cells. They also work together to remove carbon dioxide from cells and release it from the body. This entire process is summarized below. 6 Oxygen-poor blood is pumped back into the lungs where it picks up oxygen and releases CO 2. 1 Oxygen-rich blood leaves the lungs and travels into the heart. 2 Oxygen-rich blood leaves the heart and is pumped to the entire body through the arteries. 5 Veins carry oxygenpoor blood and CO 2 to the heart. 4 Oxygen-poor blood and CO 2 then return to the veins through capillaries. 3 The arteries branch into capillaries that deliver O2 and food to different parts of the body. Duplicating any part of this book is prohibited by law. 141
New York Coach, Science, Grade 7 DISCUSSION QUESTION How do the respiratory system and circulatory system work together? LESSON REVIEW 1. Which of these correctly describes the path taken by air that is inhaled? A. nose, trachea, alveoli, bronchi B. trachea, alveoli, nose, bronchi C. alveoli, bronchi, trachea, nose D. nose, trachea, bronchi, alveoli 2. Which of these is responsible for transporting blood from the heart to the rest of the body? A. arteries B. veins C. capillaries D. bronchial tubes 3. Which component of blood helps the body fight diseases? A. plasma B. red blood cells C. white blood cells D. platelets 4. Where does blood flow to from the right side of the heart? A. to the lungs B. to the brain C. to the kidneys D. to the diaphragm 142 Duplicating any part of this book is prohibited by law.