Table of Contents – pages iv-v Unit 1:What is Biology? Unit 2:Ecology Unit 3:The Life of a Cell Unit 4:Genetics Unit 5:Change Through Time Unit 6:Viruses, Bacteria, Protists, and Fungi Unit 7:Plants Unit 8:Invertebrates Unit 9:Vertebrates Unit 10:The Human Body
Table of Contents – pages iv-v Unit 1: What is Biology? Chapter 1:Biology: The Study of Life Unit 2: Ecology Chapter 2:Principles of Ecology Chapter 3:Communities and Biomes Chapter 4:Population Biology Chapter 5:Biological Diversity and Conservation Unit 3:The Life of a Cell Chapter 6:The Chemistry of Life Chapter 7:A View of the Cell Chapter 8:Cellular Transport and the Cell Cycle Chapter 9:Energy in a Cell
Unit 4: Genetics Chapter 10:Mendel and Meiosis Chapter 11:DNA and Genes Chapter 12:Patterns of Heredity and Human Genetics Chapter 13:Genetic Technology Unit 5: Change Through Time Chapter 14:The History of Life Chapter 15:The Theory of Evolution Chapter 16:Primate Evolution Chapter 17:Organizing Life’s Diversity Table of Contents – pages iv-v
Unit 6: Viruses, Bacteria, Protists, and Fungi Chapter 18:Viruses and Bacteria Chapter 19:Protists Chapter 20:Fungi Unit 7: Plants Chapter 21:What Is a Plant? Chapter 22:The Diversity of Plants Chapter 23:Plant Structure and Function Chapter 24:Reproduction in Plants Table of Contents – pages iv-v
Table of Contents – pages iv-v Unit 8: Invertebrates Chapter 25:What Is an Animal? Chapter 26:Sponges, Cnidarians, Flatworms, and Roundworms Chapter 27:Mollusks and Segmented Worms Chapter 28:Arthropods Chapter 29:Echinoderms and Invertebrate Chordates
Table of Contents – pages iv-v Unit 9: Vertebrates Chapter 30:Fishes and Amphibians Chapter 31:Reptiles and Birds Chapter 32:Mammals Chapter 33:Animal Behavior Unit 10: The Human Body Chapter 34:Protection, Support, and Locomotion Chapter 35:The Digestive and Endocrine Systems Chapter 36:The Nervous System Chapter 37:Respiration, Circulation, and Excretion Chapter 38:Reproduction and Development Chapter 39:Immunity from Disease
Unit Overview – pages 138-139 The Life of a Cell The Chemistry of Life A View of the Cell Cellular Transport and the Cell Cycle Energy in a Cell
Chapter Contents – page viii Chapter 7A View of a Cell 7.1:The Discovery of Cells 7.1:Section Check 7.2:The Plasma Membrane 7.2:Section Check 7.3:Eukaryotic Cell Structure 7.3:Section Check Chapter 7Summary Chapter 7Assessment
Chapter Intro-page 170 What You’ll Learn You will identify the parts of prokaryotic and eukaryotic cells. You will identify the structure and function of the plasma membrane. You will relate the structure of cell parts to their functions.
Chapter Intro-page 170 What You’ll Learn Cells are the foundation for the development of all life forms. Birth, growth, death, and all life functions begin as cellular functions.
Lysosomes Nucleus Plasma Membrane Endoplasmic Reticulum Mitochondrion Chapter Intro-page 174
7.1 Section Objectives – page 171 Section Objectives: • Relate advances in microscope technology to discoveries about cells and cell structure. • Compare the operation of a microscope with that of an electron microscope. • Identify the main ideas of the cell theory.
Section 7.1 Summary – pages 171-174 The History of the Cell Theory • Before microscopes were invented, people believed that diseases were caused by curses and supernatural spirits. • As scientists began using microscopes, they quickly realized they were entering a new world–one of microorganisms. • Microscopes enabled scientists to view and study cells, the basic units of living organisms.
Section 7.1 Summary – pages 171-174 Development of Light Microscopes • The first person to record looking at water under a microscope was Anton vanLeeuwenhoek. • The microscope van Leeuwenhoek used is considered a simple light microscope because it contained one lens and used natural light to view objects.
Section 7.1 Summary – pages 171-174 Development of Light Microscopes Compound light microscopes use a series of lenses to magnify objects in steps. These microscopes can magnify objects up to 1 500 times.
Section 7.1 Summary – pages 171-174 Microscope Lab Techniques Click image to view movie.
Section 7.1 Summary – pages 171-174 The Cell Theory • Robert Hooke was an English scientist who lived at the same time as van Leeuwenhock. • Hooke used a compound light microscope to study cork, the dead cells of oak bark. Cells are the basic building blocks of all living things.
Section 7.1 Summary – pages 171-174 The cell theoryis made up of three main ideas: All organisms are composed of one or more cells. The cell is the basic unit of organization of organisms. All cells come from preexisting cells.
Section 7.1 Summary – pages 171-174 Development of Electron Microscopes • The electron microscope was invented in the 1940s. • This microscope uses a beam of electrons to magnify structures up to 500 000 times their actual size.
Section 7.1 Summary – pages 171-174 Development of Electron Microscopes There are two basic types of electron microscopes. The scanning electron microscope scans the surface of cells to learn their three dimensional shape. The transmission electron microscope allows scientists to study the structures contained within a cell.
Section 7.1 Summary – pages 171-174 Two Basic Cell Types Cells that do not contain internal membrane-bound structures are called prokaryotic cells. Click here • The cells of most unicellular organisms such as bacteria do not have membrane bound structures and are therefore called prokaryotes.
7.1 Section 7.1 Summary – pages 171-174 Two Basic Cell Types Cells containing membrane-bound structures are called eukaryotic cells. Click here • Most of the multi-cellular plants and animals we know are made up of cells containing membrane-bound structures and are therefore called eukaryotes.
Section 7.1 Summary – pages 171-174 Two Basic Cell Types The membrane-bound structures within eukaryotic cells are called organelles. • Each organelle has a specific function that contributes to cell survival.
Section 7.1 Summary – pages 171-174 Two Basic Cell Types • Separation of organelles into distinct compartments benefits the eukaryotic cells. The nucleus is the central membrane-bound organelle that manages cellular functions.
Section 1 Check Question 1 How did the invention of the microscope impact society's understanding of disease? A. Scientists were able to view microorganisms that were previously unknown. B. Microscopes were invented after the development of the cell theory.
Section 1 Check Question 1 How did the invention of the microscope impact society's understanding of disease? C. It was once believed that viruses, not bacteria, caused diseases. D. Scientists could view membrane-bound organelles of prokaryotes.
Section 1 Check The answer is A. Before microscopes were invented, people believed that curses and supernatural spirits caused diseases. Microscopes enabled scientists to view cells, which led to the discovery that microorganisms cause some diseases.
Section 1 Check Question 2 Which of the following uses a beam of light and a series of lenses to magnify objects in steps? A. compound light microscope B. scanning electron microscope C. transmission electron microscope D. simple light microscope
Section 1 Check The answer is A. Most microscopes use at least two convex lenses. Compound light microscopes use a light beam and a series of lenses and can magnify objects up to about 1500 times. Electron microscopes use a beam of electrons and can magnify structures up to 500 000 times.
Section 1 Check Question 3 What makes this cell eukaryotic? Nucleus A. Because it has a cell wall. Nucleolus Chromosomes B. Because it contains DNA. Organelles Plasma membrane
Section 1 Check Question 3 What makes this cell eukaryotic? C. Because it has membrane-bound organelles. Nucleus Nucleolus Chromosomes D. Because it does not have DNA. Organelles Plasma membrane
Section 1 Check Question 3 The Answer is C. Eukaryotic cells contain membrane-bound organelles that have specific functions in the cell; prokaryotic cells do not. Nucleus Nucleolus Chromosomes Organelles Plasma membrane
Section 2 Objectives – page 175 Section Objectives • Explain how a cell’s plasma membrane functions. • Relate the function of the plasma membrane to the fluid mosaic model.
Summary Section 2 – pages 175-178 All living cells must maintain a balance regardless of internal and external conditions. Survival depends on the cell’s ability to maintain the proper conditions within itself.
Summary Section 2 – pages 175-178 Why cells must control materials The plasma membrane is the boundary between the cell and its environment.
Summary Section 2 – pages 175-178 It is the plasma membrane’s job to: • allow a steady supply of glucose, amino acids, and lipids to come into the cell no matter what the external conditions are. • remove excess amounts of these nutrients when levels get so high that they are harmful. • allow waste and other products to leave the cell.
Summary Section 2 – pages 175-178 This process of maintaining the cell’s environment is called homeostasis. Selective permeabilityis a process used to maintain homeostasis in which the plasma membrane allows some molecules into the cell while keeping others out.
Summary Section 2 – pages 175-178 Plasma Membrane Water
Summary Section 2 – pages 175-178 Structure of the Plasma Membrane The plasma membrane is composed of two layers of phospholipids back-to-back. Phospholipids are lipids with a phosphate attached to them.
Summary Section 2 – pages 175-178 Phosphate Group The lipids in a plasma membrane have a glycerol backbone, two fatty acid chains, and a phosphate group. Glycerol Backbone Two Fatty Acid Chains
Summary Section 2 – pages 175-178 Makeup of the phospholipid bilayer The phosphate group is critical for the formation and function of the plasma membrane. Phosphate Group
Summary Section 2 – pages 175-178 Makeup of the phospholipid bilayer The fluid mosaic modeldescribes the plasma membrane as a flexible boundary of a cell. The phospholipids move within the membrane.
Summary Section 2 – pages 175-178 Other components of the plasma membrane: Cholesterol plays the important role of preventing the fatty acid chains of the phospholipids from sticking together. Cholesterol Molecule
Summary Section 2 – pages 175-178 Other components of the plasma membrane: Transport proteins allow needed substances or waste materials to move through the plasma membrane. Click image to view movie.
Section 2 Check Question 1 Which of the following best describes the plasma membrane's mechanism in maintaining homeostasis? A. protein synthesis B. selective permeability C. fluid composition D. structural protein attachment
Section 2 Check The answer is B. Selective permeability is the process in which the membrane allows some molecules to pass through, while keeping others out.
Section 2 Check Question 2 Describe the structure of the plasma membrane.
Section 2 Check The plasma membrane is composed of a phospholipid bilayer, which has two layers of phospholipids back-to-back. The polar heads of phospholipid molecules contain phosphate groups and face outward.
Section 2 Check Question 3 Phospholipid molecule Why is the phosphate group of a phospholipid important to the plasma membrane? Polar head (includes phosphate group) Nonpolar tails (fatty acids)