3. Unit 1: What is Biology? Unit 2: Ecology Unit 3: The Life of a CellThe 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

4. 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 CellThe Life of a Cell Chapter 6: The Chemistry of Life Chapter 7: A View of the CellA View of the Cell Chapter 8: Cellular Transport and the Cell Cycle Chapter 9: Energy in a Cell

5. Table of Contents – pages iv-v 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

6. 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

7. 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

8. 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

9. 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

10. Chapter Contents – page viii Chapter 7 A View of a CellA View of a Cell 7.1: The Discovery of CellsThe Discovery of Cells 7.1: Section CheckSection Check 7.2: The Plasma MembraneThe Plasma Membrane 7.2: Section CheckSection Check 7.3: Eukaryotic Cell StructureEukaryotic Cell Structure 7.3: Section CheckSection Check Chapter 7 SummarySummary Chapter 7 AssessmentAssessment

11. 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.

12. Chapter Intro-page 170 Cells are the foundation for the development of all life forms. Birth, growth, death, and all life functions begin as cellular functions. What You’ll Learn

13. Plasma Membrane Lysosomes Nucleus Mitochondrion Endoplasmic Reticulum Chapter Intro-page 174

14. 7.1 Section Objectives – page 171 Relate advances in microscope technology to discoveries about cells and cell structure. Section Objectives: Compare the operation of a microscope with that of an electron microscope. Identify the main ideas of the cell theory.

15. 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. Microscopes enabled scientists to view and study cells, the basic units of living organisms. As scientists began using microscopes, they quickly realized they were entering a new world–one of microorganisms.

16. Section 7.1 Summary – pages 171-174 The first person to record looking at water under a microscope was Anton van Leeuwenhoek. The microscope van Leeuwenhoek used is considered a simple light microscope because it contained one lens and used natural light to view objects. Development of Light Microscopes

17. 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 Development of Light Microscopes

18. Section 7.1 Summary – pages 171-174 Microscope Lab Techniques Click image to view movie.

19. Section 7.1 Summary – pages 171-174 Robert Hooke was an English scientist who lived at the same time as van Leeuwenhock. The Cell Theory 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.

20. Section 7.1 Summary – pages 171-174 The cell theory is made up of three main ideas: All cells come from preexisting cells. The cell is the basic unit of organization of organisms. All organisms are composed of one or more cells.

21. Section 7.1 Summary – pages 171-174 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. Development of Electron Microscopes

22. Section 7.1 Summary – pages 171-174 There are two basic types of electron microscopes. The transmission electron microscope allows scientists to study the structures contained within a cell. The scanning electron microscope scans the surface of cells to learn their three dimensional shape. Development of Electron Microscopes

23. Section 7.1 Summary – pages 171-174 Cells that do not contain internal membrane-bound structures are called prokaryotic cells. The cells of most unicellular organisms such as bacteria do not have membrane bound structures and are therefore called prokaryotes. Two Basic Cell Types Click here

24. Section 7.1 Summary – pages 171-174 Most of the multi-cellular plants and animals we know are made up of cells containing membrane-bound structures and are therefore called eukaryotes. Cells containing membrane-bound structures are called eukaryotic cells. 7.1 Two Basic Cell Types Click here

25. Section 7.1 Summary – pages 171-174 The membrane-bound structures within eukaryotic cells are called organelles. Each organelle has a specific function that contributes to cell survival. Two Basic Cell Types

26. Section 7.1 Summary – pages 171-174 The nucleus is the central membrane- bound organelle that manages cellular functions. Separation of organelles into distinct compartments benefits the eukaryotic cells. Two Basic Cell Types

27. Section 1 Check Question 1 How did the invention of the microscope impact society's understanding of disease? B. Microscopes were invented after the development of the cell theory. A. Scientists were able to view microorganisms that were previously unknown. CA: Biology/Life Sciences 10a-10f

28. Section 1 Check D. Scientists could view membrane-bound organelles of prokaryotes. C. It was once believed that viruses, not bacteria, caused diseases. How did the invention of the microscope impact society's understanding of disease? Question 1 CA: Biology/Life Sciences 10a-10f

29. 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. CA: Biology/Life Sciences 10a-10f

30. Section 1 Check Which of the following uses a beam of light and a series of lenses to magnify objects in steps? Question 2 D. simple light microscope C. transmission electron microscope B. scanning electron microscope A. compound light microscope CA: Inv. & Exp. 1a

31. 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. CA: Inv. & Exp. 1a

32. Section 1 Check Plasma membrane Nucleus Nucleolus Chromosomes Organelles Question 3 What makes this cell eukaryotic? A. Because it has a cell wall. B. Because it contains DNA. CA: Biology/Life Sciences 1c, 1j

33. Section 1 Check Plasma membrane Nucleus Nucleolus Chromosomes Organelles Question 3 What makes this cell eukaryotic? C. Because it has membrane- bound organelles. D. Because it does not have DNA. CA: Biology/Life Sciences 1c, 1j

34. Section 1 Check Plasma membrane Nucleus Nucleolus Chromosomes Organelles Question 3 The Answer is C. Eukaryotic cells contain membrane-bound organelles that have specific functions in the cell; prokaryotic cells do not. CA: Biology/Life Sciences 1c, 1j

35. Section 2 Objectives – page 175 Section Objectives Relate the function of the plasma membrane to the fluid mosaic model. Explain how a cell’s plasma membrane functions.

36. 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.

37. Summary Section 2 – pages 175-178 Why cells must control materials The plasma membrane is the boundary between the cell and its environment.

38. Summary Section 2 – pages 175-178 It is the plasma membrane’s job to: allow waste and other products to leave the cell. remove excess amounts of these nutrients when levels get so high that they are harmful. allow a steady supply of glucose, amino acids, and lipids to come into the cell no matter what the external conditions are.

39. Summary Section 2 – pages 175-178 This process of maintaining the cell’s environment is called homeostasis. Selective permeability is a process used to maintain homeostasis in which the plasma membrane allows some molecules into the cell while keeping others out.

40. Summary Section 2 – pages 175-178 Water Plasma Membrane

41. 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.

42. Summary Section 2 – pages 175-178 The lipids in a plasma membrane have a glycerol backbone, two fatty acid chains, and a phosphate group. Glycerol Backbone Two Fatty Acid Chains Phosphate Group

43. 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

44. Summary Section 2 – pages 175-178 Makeup of the phospholipid bilayer The fluid mosaic model describes the plasma membrane as a flexible boundary of a cell. The phospholipids move within the membrane.

45. 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

46. 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.

47. Section 2 Check Which of the following best describes the plasma membrane's mechanism in maintaining homeostasis? Question 1 A. protein synthesis B. selective permeability C. fluid composition D. structural protein attachment CA: Biology/Life Sciences 1a

48. 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. CA: Biology/Life Sciences 1a

49. Section 2 Check Describe the structure of the plasma membrane. Question 2 CA: Biology/Life Sciences 1a

50. 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. CA: Biology/Life Sciences 1a

51. Section 2 Check Why is the phosphate group of a phospholipid important to the plasma membrane? Question 3 Polar head (includes phosphate group) Nonpolar tails (fatty acids) Phospholipid molecule CA: Biology/Life Sciences 1a

52. Section 2 Check When phospholipid molecules form a bilayer, the phosphate groups lie to the outside. Because phosphate groups are polar, they allow the cell membrane to interact with its watery (polar) environments inside and outside the cell. Polar head (includes phosphate group) Nonpolar tails (fatty acids) Phospholipid molecule CA: Biology/Life Sciences 1a

53. Section 2 Check Explain why the model of the plasma membrane is called the fluid mosaic model. Question 4 CA: Biology/Life Sciences 1a

54. Section 2 Check It is fluid because the phospholipid molecules move within the membrane. Proteins in the membrane that move among the phospholipids create the mosaic pattern. CA: Biology/Life Sciences 1a

55. Section 3 Objectives page 179 Section Objectives Compare and contrast the structures of plant and animal cells. Explain the advantages of highly folded membranes. Understand the structure and function of the parts of a typical eukaryotic cell.

56. Section 3 Summary – page 179-187 The plasma membrane acts as a selectively permeable membrane. Cellular Boundaries

57. Section 3 Summary – page 179-187 The cell wall The cell wall is a fairly rigid structure located outside the plasma membrane that provides additional support and protection.

58. Section 3 Summary – page 179-187 Nucleus and cell control Chromatin Nucleolus Nuclear Envelope

59. Section 3 Summary – page 179-187 Assembly, Transport, and Storage The endoplasmic reticulum (ER) is an organelle that is suspended in the cytoplasm and is the site of cellular chemical reactions.

60. Section 3 Summary – page 179-187 Assembly, Transport, and Storage Endoplasmic Reticulum (ER) Ribosomes

61. Section 3 Summary – page 179-187 Assembly, Transport, and Storage Golgi Apparatus

62. Section 3 Summary – page 179-187 Vacuoles and storage Vacuoles are membrane-bound spaces used for temporary storage of materials. Notice the difference between vacuoles in plant and animal cells. Vacuole Animal Cell Plant Cell

63. Section 3 Summary – page 179-187 Lysosomes and recycling Lysosomes are organelles that contain digestive enzymes. They digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.

64. Section 3 Summary – page 179-187 Energy Transformers: Chloroplasts are cell organelles that capture light energy and produce food to store for a later time. Chloroplasts and energy

65. Section 3 Summary – page 179-187 The chloroplasts belongs to a group of plant organelles called plastids, which are used for storage. Chloroplasts contain green pigment called chlorophyll. Chlorophyll traps light energy and gives leaves and stems their green color. Chloroplasts and energy

66. Section 3 Summary – page 179-187 Mitochondria are membrane-bound organelles in plant and animal cells that transform energy for the cell. Mitochondria and energy

67. Section 3 Summary – page 179-187 A mitochondria, like the endoplasmic reticulum, has a highly folded inner membrane. Energy storing molecules are produced on inner folds. Mitochondria and energy

68. Section 3 Summary – page 179-187 Cells have a support structure called the cytoskeleton within the cytoplasm. The cytoskeleton is composed of microtubules and microfilaments. Microtubules are thin, hollow cylinders made of protein and microfilaments are thin solid protein fibers. Structures for Support and Locomotion

69. Section 3 Summary – page 179-187 Some cell surfaces have cilia and flagella, which are structures that aid in locomotion or feeding. Cilia and flagella can be distinguished by their structure and by the nature of their action. Cilia and flagella

70. Section 3 Summary – page 179-187 Cilia are short, numerous, hair-like projections that move in a wavelike motion. Cilia and flagella Cilia

71. Section 3 Summary – page 179-187 Flagella are long projections that move in a whip-like motion. Flagella and cilia are the major means of locomotion in unicellular organisms. Cilia and flagella Flagella

72. Section 3 Check What is the primary function of the cell wall? Question 1 D. acquire nutrients from environment C. control activity of organelles B. provide support A. act as selectively permeable membrane CA: Cell Bio 1c, 1j

73. The answer is B. The cell wall is an inflexible, porous barrier that provides support but does not select which molecules can enter the cell. Section 3 Check CA: Cell Bio 1c, 1j

74. Question 2 DNA Plasma membrane Cell wall Describe the control center of a prokaryotic cell. Ribosomes Section 3 Check CA: Cell Bio 1c

75. DNA Plasma membrane Cell wall Prokaryotic cells do not have true nuclei; their DNA is not separated from the rest of the cell by a membrane. Ribosomes Section 3 Check CA: Cell Bio 1c

76. Which of the following structures is the site of protein synthesis? Question 3 D. Lysosome C. Vacuole B. Ribosome A. Golgi apparatus Section 3 Check CA: Cell Bio 1d

77. The answer is B. Ribosomes are the sites where the cell produces proteins according to the directions of DNA. They can be attached to the surface of the endoplasmic reticulum or float freely in the cytoplasm. Section 3 Check CA: Cell Bio 1d

78. What is the advantage of having numerous folds in the ER? Question 4 B. It can create more vesicles in a smaller space. A. It enables the ER to lie snugly against the nucleolus. Section 3 Check CA: Cell Bio 1e

79. D. A large amount of work can be done in a small space. What is the advantage of having numerous folds in the ER? Question 4 C. It can capture more light energy with more folds. Section 3 Check CA: Cell Bio 1e

80. The answer is D. The ER is arranged in a series of folded membranes, which, if spread out, would take up tremendous space. Section 3 Check CA: Cell Bio 1e

81. B. It contains a greater number of plastids. What could you predict about a plant cell that contains fewer chloroplasts than other plant cells? Question 5 A. It contains less chlorophyll. D. It will appear darker green in color. C. It will have an increased rate of light energy capture. Section 3 Check CA: Cell Bio 1f

82. The answer is A. Chloroplasts are among the plant organelles known as plastids and contain the green pigment chlorophyll. Chlorophyll traps light energy from the Sun and gives leaves and stems their green color. Section 3 Check CA: Cell Bio 1f

83. A mutation results in the inner membranes of a liver cell's mitochondria being smooth, rather than folded. Which of the following would you expect? Question 6 B. It can create more vesicles in a smaller space A. more efficient storage of cellular energy Section 3 Check CA: Cell Bio 1g

84. A mutation results in the inner membranes of a liver cell's mitochondria being smooth, rather than folded. Which of the following would you expect? Question 6 D. fewer ribosomes available for protein synthesis C. decreased energy available to the cell Section 3 Check CA: Cell Bio 1g

85. The answer is C. Mitochondria transform energy for the cell. A highly folded inner membrane provides a greater surface area for producing energy- storing molecules. Section 3 Check CA: Cell Bio 1g

86. Chapter Summary – Section 1 The cell theory states that the cell is the basic unit of organization, all organisms are made up of one or more cells, and all cells come from preexisting cells. Main Ideas Microscopes enabled biologists to see cells and develop the cell theory.

87. Cells are classified as prokaryotic and eukaryotic based on whether or not they have membrane-bound organelles. Main Ideas Continued Using electron microscopes, scientists can study cell structure in detail. Chapter Summary – Section 1

88. Chapter Summary – Section 2 The fluid mosaic model describes the plasma membrane as a phospholipid bilayer with embedded proteins. Main Ideas Through selective permeability, the plasma membrane controls what enters and leaves a cell.

89. Main Ideas Eukaryotic cells have a nucleus and organelles, are enclosed by a plasma membrane, and some have a cell wall that provides support and protection. Cells make proteins on ribosomes that are often attached to the highly folded endoplasmic reticulum. Cells store materials in the Golgi apparatus and vacuoles. Chapter Summary – Section 2

90. The cytoskeleton helps maintain cell shape, is involved in the movement of organelles and cells, and resists stress placed on cells. Main Ideas Continued Mitochondria break down food molecules to release energy. Chloroplasts convert light energy into chemical energy. Chapter Summary – Section 3

91. Chapter Assessment Question 1 Which of the following is a main idea of the cell theory? D. All cells come from preexisting cells. C. All cells come from two parent cells. B. The organelle is the basic unit structure and organization of organisms. A. All organisms are composed of one cell. CA: Biology/Life Sciences 1a-1j

92. Chapter Assessment The answer is D. The cell theory states that a cell divides to form two identical cells. CA: Biology/Life Sciences 1a-1j

93. Chapter Assessment Question 2 In what type of cell would you find chlorophyll? D. fungus C. plant B. animal A. prokaryote CA: Biology/Life Sciences 1f

94. Chapter Assessment The answer is C. Chlorophyll is the green pigment found in the chloroplasts of plant cells. CA: Biology/Life Sciences 1f

95. Chapter Assessment Question 3 Which of these structures packs proteins into membrane-bound structures? A. B. C. D. CA: Biology/Life Sciences 1e

96. Chapter Assessment Answer C depicts the Golgi apparatus, which sorts proteins and packs them into vesicles. CA: Biology/Life Sciences 1e

97. Chapter Assessment Question 4 What is the difference between the cell wall and the plasma membrane? Cell wall Plasma membrane Inside cell Outside cell CA: Biology/Life Sciences 1a, 1j

98. Chapter Assessment The plasma membrane is a flexible boundary between the cell and its environment that controls the supply of nutrients, waste, and other products entering and leaving the cell. The cell wall is a rigid structure found in plant cells, fungi, bacteria and some protists that provides support and protection but does not select which molecules can enter or leave the cell. Cell wall Plasma membrane Inside cell Outside cell CA: Biology/Life Sciences 1a, 1j

99. Chapter Assessment Question 5 Which of the following organelles is not bound by a membrane? D. lysosome C. vacuole B. Golgi apparatus A. ribosome CA: Biology/Life Sciences 1d

100. Chapter Assessment The answer is A. Ribosomes are simple structures made of RNA and protein and are not bound by membranes. Ribosomes CA: Biology/Life Sciences 1d

101. Chapter Assessment Question 6 Explain the importance of cholesterol to the plasma membrane. Cholesterol molecule Phospholipid molecules CA: Biology/Life Sciences 1a, 1h

102. Chapter Assessment Cholesterol helps to stabilize the phospholipids in the plasma membrane by preventing their fatty acid tails from sticking together. Cholesterol molecule Phospholipid molecules CA: Biology/Life Sciences 1a, 1h

103. Chapter Assessment Question 7 In which of the following pairs are the terms related? D. plastid – storage C. microfilaments – locomotion B. prokaryote – mitochondria A. cell wall – selective permeability CA: Biology/Life Sciences 1h

104. Chapter Assessment The answer is D. Plastids are plant organelles that are used for storage. CA: Biology/Life Sciences 1h

105. Chapter Assessment Question 8 Which of the following structures is found in both plant and animal cells? D. thylakoid membrane C. mitochondrion B. cell wall A. chloroplast CA: Biology/Life Sciences 1g

106. Chapter Assessment The answer is C. Mitochondria are the organelles in both plant and animal cells that transform energy for the cell. CA: Biology/Life Sciences 1g

107. Chapter Assessment Question 9 __________ span the entire plasma membrane and regulate which molecules enter and leave the cell. D. Microtubules C. Ribosomes B. Cholesterol molecules A. Transport proteins CA: Biology/Life Sciences 1a

108. Chapter Assessment The answer is A. Transport proteins form the selectively permeable membrane and move needed substances or waste materials through the plasma membrane. CA: Biology/Life Sciences 1a

109. Chapter Assessment Question 10 Compare the cytoskeleton of a cell to the skeleton of the human body. CA: Biology/Life Sciences 1j

110. Chapter Assessment The cytoskeleton and skeleton are similar in that both form a framework. However, the cytoskeleton is a constantly changing structure with the ability to be disassembled in one place and reassembled in another. CA: Biology/Life Sciences 1j

111. A prokaryotic cell does not have internal organelles surrounded by a membrane. Most of a prokaryote’s metabolism takes place in the cytoplasm. 1. Ribosomes 2. DNA 3. Plasma membrane 4. Cell wall Click here to return to chapter summary Chapter Assessment CA: Biology/Life Sciences 1j

112. This eukaryotic cell from an animal has distinct membrane-bound organelles that allow different parts of the cell to perform different functions. 4. Plasma membrane 1. Nucleus 2. Nucleolus 3. Chromosomes 5. Organelles Click here to return to chapter summary Chapter Assessment CA: Biology/Life Sciences 1j

113. Photo Credits Digital Stock PhotoDisc Alton Biggs

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115. End of Chapter 7 Show