Natural Sciences Grade 9 Textbook and Workbook Santie du Plessis Pikkie du Toit Carlien Fanoy Natalie Janse van Rensburg Susan Keuris Patricia Lees-Rolfe Judy McDougall
Doc Scientia Posbus 7011 Ansfrere 1711 www.docscientia.co.za For any queries and feedback: info@docscientia.co.za Jacques Fanoy or Stephan Fanoy Office: 011 472 8728 Fax: 086 546 1423 ISBN: 978-1-920537-30-2 First edition December 2011 Revised edition December 2012 Second edition December 2013 Revised edition December 2014; 2015 Graphic design: Helene Jonck All rights reserved. No part of this publication may be reproduced in any form or by any means mechanical or electronic, including recordings or tape recordings and photocopying without the prior permission of the publisher.
Unit INDEX TERM 1 LIFE AND LIVING 13 Unit 1 CELLS AS THE BASIC UNITS 13 Page 1.1 Plant cells and animal cells 13 1.2 Structure of cells 14 1.3 Differences between plant cells and animal cells 15 Project 15 1.4 Cells in tissues, organs and systems 15 Activity 1 15 Activity 2 16 Case study 19 Practical task 1 21 Exercise 1 21 Summary of Unit1 24 Mind maps of Unit 1 25 Unit 2 SYSTEMS IN THE HUMAN BODY 27 2.1 Introduction 28 Practical task 2 28 2.2 Digestive system 28 2.2.1 Steps in digestion 28 2.2.2 Types of digestion 29 2.2.3 Organs 29 2.2.4 Functions of the organs 30 2.2.5 Nutrition and nutrients 34 2.2.6 Balanced diet 36 Activity 3 37 Activity 4 37 Practical investigation 1 37 2.2.7 Health issues 39 Activity 5 39 Exercise 2 41 2.3 Muscular system 46 2.3.1 Skeleton 46 2.3.2 Muscles 48 2.3.3 Tendons, ligaments and cartilage 49 2.3.4 Diseases that affect the skeleton 49 Exercise 3 49 2.4 Circulatory system 52 2.4.1 Blood 52 2.4.2 Anatomy 52 2.4.3 Blood vessels 54 2.4.4 Heart 54 Practical investigation 2 55 Practical task 3 57 2.4.5 Health issues 57 Activity 6 58 Exercise 4 59 2.5 Respiratory system 63
2.5.1 Anatomy 63 2.5.2 Gaseous exchange and diffusion 65 Practical task 4 66 2.5.3 Respiration 66 Activity 7 66 2.5.4 Differences between inhalation and exhalation 66 2.5.5 Health issues 67 Activity 8 67 Exercise 5 68 2.6 Excretory system 73 2.6.1 Anatomy 73 2.6.2 Health issues 75 Exercise 6 76 2.7 Nervous system and sensory organs 78 2.7.1 Eye (sight) 78 2.7.2 Ear (hearing) 80 2.7.3 Tongue (taste) 81 2.7.4 Skin (touch) 82 2.7.5 Nose (smell) 83 2.7.6 Impulses and the brain 84 2.7.7 Thermoregulation 86 2.7.8 Health issues 87 2.7.9 The impact of drugs and alcohol on the brain 88 Exercise 7 88 Summary of Unit 2 92 Mind maps of Unit 2 100 Unit 3 HUMAN REPRODUCTION AN PUBERTY 107 3.1 Introduction 107 3.2 Male reproductive system 107 3.3 Female reproductive system 108 3.4 Sexual intercourse 109 3.5 Puberty 109 3.6 Phases of reproduction 110 3.7 Contraception 112 3.8 Health issues 112 Activity 9 113 Activity 10 114 Exercise 8 114 Summary of Unit 3 118 Mind maps of Unit 3 119 Glossary 120 Term test 123 TERM 2 MATTER AND MATERIALS 139 Unit 1 COMPOUNDS AND CHEMICAL REACTIONS 139 1.1 Periodic Table 139 1.1.1 General information 140 1.1.2 Representation of elements 141 1.2 Compounds 141 Practical task 5 143 Exercise 9 144
1.3 Chemical reactions 148 1.3.1 Chemical equations 148 Practical task 6 149 Exercise 10 151 1.3.2 Balancing 154 Exercise 11 156 Summary of Unit 1 158 Mind maps of Unit 1 160 Unit 2 METALS AND NON-METALS 161 2.1 Indicators 161 2.2 ph scale 162 Practical investigation 3 163 Practical investigation 4 163 2.3 Reactions of metals with oxygen 164 Practical investigation 5 165 2.3.1 Rust 167 2.3.2 Prevention of rust 167 2.4 Reactions of non-metals with oxygen 168 Practical investigation 6 168 Exercise 12 171 Summary of Unit 2 175 Mind maps of Unit 2 176 Unit 3 ACIDS AND BASES 177 3.1 Acids 177 3.2 Bases 178 Practical task 7 179 Exercise 13 179 3.3 Reactions of acids 180 3.3.1 Acid with a metal 180 Practical investigation 7 180 Practical investigation 8 183 Exercise 14 183 3.3.2 Acid with a metal oxide 184 Activity 11 186 3.3.3 Acid with a metal hydroxide 186 Practical investigation 9 187 3.3.4 Acid with a metal carbonate 188 Practical investigation 10 188 Activity 12 190 Exercise 15 190 Summary of Unit 3 194 Mind maps of Unit 3 195 Glossary 196 Term test 197 TERM 3 ENERGY AND CHANGE 205 Unit 1 FORCES 205 1.1 What is a force? 205 Practical task 8 205 Practical task 9 206
Practical task 10 206 Practical task 11 208 Exercise 16 209 1.2 Types of forces 210 1.2.1 Gravitational force 210 Practical task 12 210 Practical task 13 212 1.2.2 Magnetic forces 213 Practical task 14 213 Practical investigation 11 214 Practical investigation 12 215 Practical investigation 13 216 1.2.3 Electrostatic forces 217 Practical investigation 14 218 Exercise 17 221 Summary of Unit 1 222 Mind maps of Unit 1 224 Unit 2 CELLS 225 2.1 Source 225 2.2 Chemical reactions 225 Practical investigation 15 226 2.3 Connections 226 2.3.1 Series 226 Practical investigation 16 226 2.3.2 Parallel 227 Practical investigation 17 227 Exercise 18 228 Summary of Unit 2 230 Unit 3 SERIES CIRCUITS AND PARALLEL CIRCUITS 231 3.1 Conductors and resistors 231 3.1.1 Conductors 231 3.1.2 Resistors 232 3.1.3 Factors that influence resistance 233 Practical investigation 18 233 3.2 Electrical circuits 235 3.2.1 Current 235 3.2.2 Potential difference 236 3.2.3 Resistance 237 3.3 Series connection 237 Practical investigation 19 237 3.4 Parallel connection 238 Practical investigation 20 239 Exercise 19 240 Summary of Unit 3 242 Mind maps of Unit 3 244 Unit 4 SAFETY WITH ELECTRICITY 245 4.1 Wiring of households 245 Practical task 15 247 4.2 Safety measures 247
4.2.1 Fuses and circuit breakers 247 4.2.2 Lightning conductors 248 Activity 13 249 4.3 Electrical energy theft 250 Activity 14 250 Exercise 20 251 Summary of Unit 4 252 Mind maps of Unit 4 253 Unit 5 NATIONAL ELECTRICITY GRID 255 5.1 National network 255 5.2 Coal power stations 255 5.3 Alternative sources 257 Activity 15 259 Exercise 21 260 Summary of Unit 5 264 Unit 6 COST OF ELECTRICAL POWER 267 6.1 Cost calculation 267 6.2 Saving electricity 269 Activity 16 269 Exercise 22 270 Summary of Unit 4 272 Glossary 273 Term test 275 TERM 4 EARTH AND BEYOND 283 Activity 17 285 Unit 1 LITHOSPHERE 287 1.1 What is the lithosphere? 287 1.2 Rock cycle 288 1.2.1 Types of rock 288 1.2.1.1 Igneous rock 289 1.2.1.2 Sedimentary rock 289 1.2.1.3 Metamorphic rock 290 1.2.2 Steps of the rock cycle 290 Activity 18 292 1.3 Minerals and ore 294 Exercise 23 295 1.4 Extraction of minerals in South Africa 298 1.4.1 Indigenous technology of extraction 298 1.4.2 Modern day processes for extraction 298 Activity 19 299 1.4.3 Environmental impact of mines 300 Activity 20 301 Exercise 24 301 Summary of Unit 1 303 Mind maps of Unit 1 305 Unit 2 ATMOSPHERE 307 2.1 Composition 307 2.2 Layers of the atmosphere 308 2.2.1 Troposphere 310 2.2.2 Stratosphere 310
2.2.3 Mesosphere 311 2.2.4 Thermosphere 311 2.3 The greenhouse effect 312 Activity 21 313 Exercise 25 313 2.4 Stars 315 2.4.1 Birth 315 2.4.2 Life 316 2.4.3 Death 317 Activity 22 318 Activity 23 318 Summary of Unit 2 319 Mind maps of Unit 2 321 Glossary 324 Term test 325 Information sheet 331 Work cited 332
Cells as the basic units UNIT 1 Cells as the basic units of life TERM 1: LIFE AND LIVING Life and living Systems in the human body CELLS AS THE BASIC UNITS A cell is the basic structural and functional unit of all living organisms. Cells are microscopic and cannot be observed with the naked eye. Microscopes are used to observe cells. 1.1 Plant cells and animal cells Human reproduction and puberty Plant cells and animal cells Structure of cells Differences between plant cells and animal cells Cells in tissues, organs and systems Cells 1. Membrane 2. Cytoplasm 3. Nucleus 4. Organelles 1. Membrane: The membrane surrounds the cell. It allows certain substances to move in and out of the cell. The membrane is living, thin and pliable. 2. Cytoplasm: The cytoplasm is a liquid in which the chemical processes (metabolism) can take place in the cell. The largest part of the cell consists of cytoplasm, which is a jelly-like substance. Doc Scientia NATURAL SCIENCES textbook and workbook - Grade 9 13
life and living 3. Nucleus (core): The nucleus is surrounded by the nucleus membrane. The nucleus contains the DNA of the cell. DNA carries the genetic code with which the cell reproduces. DNA contains hereditary characteristics which determine things like the colour of your eyes. Each persoon's DNA is unique. Due to the variation, differences occur in species. The nucleus controls the life functions and processes of the cell. 4. Organelles: Organelles include the mitochondria and vacuole. The mitochondria is responsible for respiration in cells, and release energy. 1.2 Structure of cells The structure of the plant cell is as follows: cell wall cell membrane cytoplasm mitochondria The structure of the animal cell is as follows: vacuole nuclear membrane nucleoplasm tonoplast cell sap chloroplast nuclear membrane vacuole nucleus mitochondria nucleoplasm cell membrane cytoplasm 14 NATURAL SCIENCES textbook and workbook - Grade 9 Doc Scientia } } } nucleus
life and living 1.3 Differences between plant cells and animal cells Plant cell 1. Cell wall Present It consists of non-living cellulose which is rigid. The cell wall gives the shape of the cell and provides protection. 2. Shape of Inflexible and firm cell 3. Vacuole Large vacuoles The vacuole contributes to the shape of the cell. The vacuole is also used as storage for nutrients, water and even waste products. 4. Chloroplast Chloroplasts are only found in green plants. Chloroplasts contain chlorophyll which allows the plant to photosynthesise. Photosynthesis is the process whereby green plants produce food (glucose and starch) in the presence of sunlight. Project Date: Animal cell Not present No fixed form Small vacuoles Vacuoles in animal cells are temporary or not present. Animal cells do not contain chloroplasts. Build a 3D plant cell that meets the following requirements: It must be approximately the size of an A4 paper. Be as creative as possible. Use different kinds and colours of sweets, play dough, different colours of cardboard or anything from nature to represent the different parts of the cell. 1.4 Cells in tissues, organs and systems Cells are found in a variety of sizes and shapes. Microscopic organisms, like bacteria, consist of only one cell and are studied under a microscope. Macroscopic organisms, like people, consist of a large number of cells. Activity 1 Date: Do research on the history and discovery of light microscopes and electron microscopes. Search for pictures. Make a poster. Do a presentation in class. Doc Scientia NATURAL SCIENCES textbook and workbook - Grade 9 15
Activity 2 life and living Study the named sketch of the basic light microscope. Date: Complete the table below about the function of each of the parts that are listed. Part coarse focus knob fine focus knob arm adjustable inclination base Function eye piece Eye piece Tube Coarse focus knob Fine focus knob 16 NATURAL SCIENCES textbook and workbook - Grade 9 Doc Scientia tube revolving nosepiece small objective large objective clamps table/stage diaphragm mirror/light source
Arm Part Revolving nosepiece Objectives Table/stage Clamps Diaphragm Light source Base Function There are cells that are specialised. This means that these cells are adapted to perform specific functions. Here are a few examples of specialised cells: Stem cells Muscle cells Cell life and living Function These cells have the ability to: divide and develop into different types of cells. Example: Stem cells can develop into nerve cells, muscle cells and bone cells. These cells contract and relax to enable movement. Doc Scientia NATURAL SCIENCES textbook and workbook - Grade 9 17
Nerve cells Red blood cells Cell life and living Cell A group of cells that function together for the same purpose forms tissue. A group of systems that function together forms an organism. Function Nerve cells transfer electrical impulses in the nerves and the spinal cord. The red blood cells transport oxygen throughout the body. A group of tissues that function together forms an organ. A group of organs that function together forms a system. 18 NATURAL SCIENCES textbook and workbook - Grade 9 Doc Scientia
Case study Date: life and living Stem cells and stem cell research Stem cell research has been hailed as a miracle cure by the medical fraternity, because there is the possibility of solutions for incurable diseases, e.g. cancer, Alzheimer s and Parkinson s. Researchers believe that stem cells can be used to regenerate damaged and diseased organs. On the other hand, stem cell research has been highly controversial, due to the ethical issues concerned with the culture and use of stem cells derived from human embryos. But what is a stem cell? Stem cells are unspecialised cells that have two defining properties: the ability to differentiate into any other type of cell, and the ability to self-regenerate (they can divide and produce more stem cells). Stem cell research is research done on embryonic stem cells. It focuses on medical prospects such as healing diseases that are currently incurable. There are ethical questions that come to light when one talks about stem cell research. 1. The research destroys human embryos. Every living person started life as an embryo. The debate is whether the destruction of embryos is murder or not. 2. Stem cell research could lead to unethical behaviour, for example embryo farms, cloned babies and the use of foetuses for organ donation. The counter-arguments are: 1. Embryos cannot be compared to living, complete organisms. Therefore the use of embryo stem cells cannot be considered murder. 2. If it is unethical to use embryos for research, then it is just as unethical to use embryos for in-vitro fertilisation. Most fertility clinics prepare more embryos than they need. The excess embryos are frozen or destroyed. If it is therefore immoral to use embryos to cure devastating diseases, it is also immoral to use embryos to overcome infertility. Questions: 1. What is a stem cell? 2. What is an embryo? _ Doc Scientia NATURAL SCIENCES textbook and workbook - Grade 9 19
life and living 3. What is stem cell research? 4. Why was stem cell research hailed as a miracle cure by the medical fraternity? 5. Which two ethical questions caused controversy in the debate about stem cell research? State your answer in just one sentence. 6. Give your own opinion of stem cell research. Do you agree with it or not? Do further research about stem cell research to support your answer for Question 6. Discuss your findings in class. Take into consideration that stem cells can also be obtained from blood from the umbilical cord after birth. How does this statement influence your opinion? 20 NATURAL SCIENCES textbook and workbook - Grade 9 Doc Scientia
Practical task 1 Exercise 1 1. Name three specialised cells as well as the function of each. life and living Date: 2. Explain the following briefly: Tissue Organs Systems Organism 3. Name the four parts found in all cells. 4. What is the function of the cell nucleus? 5. Draw a simple sketch to represent an animal cell. Remember to give your sketch a heading and labels. Date: Prepare plant cells and animal cells (e.g. cells from an onion and mucous) and study it under a microscope. Draw and name the cells that are studied. Doc Scientia NATURAL SCIENCES textbook and workbook - Grade 9 21
life and living 6 Study the sketches in the following table. Identify them as cells, tissue, organs, systems or organisms. 6.1 6.2 6.3 6.4 6.5 6.6 6.7 22 NATURAL SCIENCES textbook and workbook - Grade 9 Doc Scientia
7. Draw a simple sketch to represent a plant cell. Remember to give your sketch a heading and labels. 8 What is the function of: 8.1 the cell wall? life and living 8.2 the chloroplasts? 8.3 the vacuole? Notes Doc Scientia NATURAL SCIENCES textbook and workbook - Grade 9 23
life and living Summary 1. Membrane 2. Cytoplasm 3. Nucleus 4. Organelles Plant cell 1. Cell wall Present It consists of non-living cellulose which is rigid. The cell wall gives the shape of the cell and provides protection. 2. Shape of cell Inflexible and firm 3. Vacuole Large vacuoles The vacuole contributes to the shape of the cell. The vacuole is also used as storage for nutrients, water and even waste products. 4. Chloroplast Chloroplasts are only found in green plants. Chloroplasts contain chlorophyll which allows the plant to photosynthesise. Photosynthesis is the process whereby green plants produce food (glucose and starch) in the presence of sunlight. Cell Stem cells Muscle cells Nerve cells Red blood cells Cell Cells Function Not present Animal cell No fixed form Small vacuoles Vacuoles in animal cells are temporary or not present. Animal cells do not contain chloroplasts. These cells have the ability to divide and develop into different types of cells. These cells contract and relax to enable movement. Nerve cells transfer electrical impulses in the nerves and the spinal cord. The red blood cells transport oxygen throughout the body. A group of cells that function together for the same purpose forms tissue. A group of systems that function together forms an organism. A group of tissues that function together forms an organ. A group of organs that function together forms a system. 24 NATURAL SCIENCES textbook and workbook - Grade 9 Doc Scientia
All cells contain Plant cell A group of cells A group of systems 1. Shape Rigid Flexible 2. Cell wall 3. Vacuole containing cell sap 4. Chloroplast CELLS AMPLE Animal cell A group of tissue A group of organs