Chapter 7 7-1 Life Is Cellular
The Discovery of the Cell Anton van Leeuwenhoek used a single-lens microscope to observe tiny little organisms in pond water.
The Discovery of the Cell In 1665, Robert Hooke used an early microscope to look at a thin slice of cork. Cork looked like thousands of tiny chambers. He called it cells
The Cell Theory 1838, Matthias Schleiden, all plants were made of cells. 1839, Theodor Schwann, all animals were made of cells. 1855, Rudolph Virchow, new cells were created from existing cells. These discoveries led to the cell theory.
The Cell Theory Section 4-1 The cell theory states: All living things are composed of cells. Cells are the basic units of structure and function in living things. New cells are produced from existing cells.
Exploring the Cell Section 4-1 Electron Microscopes Electron microscopes reveal details 1000 times smaller than those visible in light microscopes. It can be used to visualize only nonliving, preserved cells and tissues.
Exploring the Cell Transmission electron microscopes (TEMs) Used to study cell structures and large protein molecules Specimens must be cut into ultra-thin slices
Exploring the Cell Scanning electron microscopes (SEMs) Produce three-dimensional images of cells Specimens do not have to be cut into thin slices
Prokaryotes and Eukaryotes Cells come in a variety of shapes and sizes. All cells: are surrounded by a barrier called a cell membrane. at some point in life contain DNA.
Prokaryotes and Eukaryotes Cells classified in two categories, with or without a nucleus. Nucleus contains the cell's genetic material in the form of DNA. The nucleus controls many of the cell's activities.
Prokaryotes and Eukaryotes Section 4-1 Eukaryotes are cells that contain nuclei. Prokaryotes do not contain nuclei.
Prokaryotes and Eukaryotes Section 4-1 Prokaryotic cells have genetic material that is not contained in a nucleus, and no membrane-bound organelles.
Prokaryotes and Eukaryotes Section 4-1 Prokaryotic They are generally smaller and simpler than eukaryotic cells. Bacteria are prokaryotes.
Prokaryotes and Eukaryotes Eukaryotic cells contain a nucleus in which their genetic material is separated from the rest of the cell.
Prokaryotes and Eukaryotes Eukaryotic cells contain a nucleus in which their genetic material is separated from the rest of the cell.
Prokaryotes and Eukaryotes Eukaryotic cells are generally larger and more complex, contain dozens of structures and internal membranes.
Prokaryotes and Eukaryotes Eukaryotic cells are highly specialized. Plants, animals, fungi, and protists are eukaryotes.
Quiz 7.1 Section 4-1 1. The cell theory states that new cells are produced from A. nonliving material. B. existing cells. C. cytoplasm. D. Prokaryotes
Quiz 7.1 Section 4-1 2- Who was the first person to identify and see cells? a. Anton van Leeuwenhoek b. Robert Hooke c. Matthias Schleiden d. Rudolf Virchow
Quiz 7.1 Section 4-1 3. Which organism listed is a prokaryote? A. protist B. bacterium C. fungus D. plant
Quiz 7.1 Section 4-1 4. Which cell structure contains the cell s genetic material and controls the cell s activities? a. organelle b. nucleus c. cell envelope d. cytoplasm
Quiz 7.1 Section 4-1 5. Eukaryotes usually contain a. a nucleus. b. specialized organelles. c. genetic material. d. all of the above
Quiz 7.1 Section 4-1 6. Prokaryotes lack a. cytoplasm. b. a cell membrane. c. a nucleus. d. genetic material.
Quiz 7.1 Section 4-1 7. Looking at a cell under a microscope, you note that it is a prokaryote. How do you know? a. The cell lacks a cell membrane. b. The cell lacks a nucleus. c. The cell lacks cytoplasm. d. The cell lacks genetic material.
Quiz 7.1 Section 4-1 8. Electron microscopes can reveal details a. 100 times smaller than those visible in light microscopes. b. the same size as those visible in light microscopes. c. 1000 times smaller than those visible in light microscopes. d. 100 times larger than those visible in light microscopes.
Quiz 7.1 Section 4-1 9. The work of Schleiden and Schwann can be summarized by saying that a. plants and animals have specialized cells. b. all plants and animals are made of cells. c. all animals are made of cells. d. all plants are made of cells.
Quiz 7.1 Section 4-1 10. The cells of multicellular organisms are a. simpler than those of unicellular organisms. b. not dependent on one another. c. specialized to perform different tasks. d. smaller than those of unicellular organisms.
Quiz 7.1 Section 4-1 11. Which type(s) of microscopes can produce three-dimensional images of cells? a. transmission electron microscopes b. scanning electron microscopes c. both A and B d. neither A nor B
Quiz 7.1 Section 4-1 12. Which of the following organisms are prokaryotes? a. animals b. bacteria c. plants d. all of the above
Quiz 7.1 Section 4-1 13. The cell theory applies to a. plants and animals. b. bacteria. c. multicellular organisms. d. all of the above
Quiz 7.1 Section 4-1 14. Which of the following is NOT a principle of the cell theory? a. All living things are made of cells. b. All cells are produced by existing cells. c. Cells are the basic units of life. d. Very few cells reproduce.
7.2 Eukaryotic Cell Structure
7.2 Eukaryotic Cell Structure Name Class Date Name Class Date Section 7 2 Eukaryotic Cell Structure (pages 174 181) Plant Cell Use the words below to label the plant cell. Some structures have already been labeled for you. This section describes the functions of the major cell structures. Comparing a Cell to a Factory (page 174) 1. What is an organelle? It is a structure in eukaryotic cells that acts as if it is a specialized organ. 2. Label the structures on the illustration of the plant cell. cell wall mitochondrion ribosome chloroplast nucleus vacuole Plant Cell smooth endoplasmic reticulum Vacuole Mitochondrion Chloroplast Ribosome Nucleus Golgi apparatus cell membrane rough endoplasmic reticulum 3. Circle the letter of each structure that animal cells contain. a. chloroplasts b. lysosomes c. mitochondria d. ER 4. Circle the letter of each structure that plant cells contain. a. cell wall b. ER c. lysosomes d. chloroplast Nucleus (page 176) 5. What is the function of the nucleus? It is the control center of the cell. 6. What important molecules does the nucleus contain? It contains DNA. Pearson Education, Inc. All rights reserved. Use the diagram to answer the questions. 1. Which structure is found in a plant cell but not in an animal cell? Circle the correct answer. chloroplast cell membrane ribosome 2. What is the main function of vacuoles? 7. The granular material visible within the nucleus is called chromatin.
Eukaryotic Cell Structure Section 4-1 Structures in eukaryotic cell that perform important cellular functions are known as organelles.
Eukaryotic Cell Structure Eukaryotic cell are divided into two major parts: The nucleus and the cytoplasm. The Cytoplasm is the portion of the cell outside the nucleus.
Plant Cell Eukaryotic Cell Structure Nucleolus Nucleus Nuclear envelope Smooth endoplasmic reticulum Rough endoplasmic reticulum Cell wall Cell membrane Chloroplast Vacuole Ribosome (free) Ribosome (attached) Golgi apparatus Mitochondrion
Eukaryotic Cell Structure Animal Cell Nucleus Nuclear envelope Rough endoplasmic reticulum Nucleolus Smooth endoplasmic reticulum Ribosome (free) Cell membrane Centrioles Ribosome (attached) Golgi apparatus Mitochondrion
Nucleus Section 4-1 Nucleus is the cell s control center. It contains the cell's DNA and the coded instructions for making proteins and other important molecules. Chromatin Nucleolus Nuclear envelope Nuclear pores
Ribosome One of the most important jobs in the cell is making proteins. Proteins are assembled on ribosomes.
Ribosome Section 4-1 Ribosomes are small particle in the cell on which proteins are assembled; made of RNA and protein
Endoplasmic Reticulum There are two types of ER rough and smooth. Ribosome (attached)
Endoplasmic Reticulum ER involved in the synthesis of proteins is called rough endoplasmic reticulum, or rough ER Ribosomes
Endoplasmic Reticulum ER involved in the synthesis of proteins is called rough endoplasmic reticulum, or rough ER Ribosomes
Endoplasmic Reticulum Smooth ER contains enzymes that perform specialized tasks, including synthesis of membrane lipids and the detoxification of drugs Ribosomes
Golgi Apparatus Section 4-1 The function of the Golgi apparatus is to modify, sort, and package proteins from the endoplasmic reticulum for storage or secretion outside the cell.
Lysosome Lysosome is a specialized vesicle that holds a variety of enzymes. http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation lysosomes.html
Vacuoles Section 4-1 In many plant cells there is a single, large central vacuole filled with liquid. Vacuole
Vacuoles Vacuoles are also found in some unicellular organisms. Paramecium contains a contractile vacuole that pumps excess water out of the cell. Contractile vacuole
Mitochondria Nearly all eukaryotic cells contain mitochondria. Mitochondria convert the chemical energy stored in food into usable energy in the cell. Mitochondrion
Mitochondria Mitochondria are enclosed by two membranes an outer and an inner membrane. The inner membrane is folded up inside the organelle. Mitochondrion
Chloroplasts
Chloroplasts Plants and some other organisms contain chloroplasts, to capture energy from sunlight and convert it into chemical energy in a process called photosynthesis. Chloroplast
Chloroplasts Stroma Granum Do not post photos on Internet Outer membrane Inner membrane Thylakoid lumen Thylakoid membrane 1 µm
Cytoskeleton A network of protein filaments that help the cell to maintain its shape. It is also involved in movement. The cytoskeleton is made up of: microfilaments microtubules
Cytoskeleton Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Mitochondrion
Centrioles Centrioles are located near the nucleus and help to organize cell division. Centrioles
Quiz 7.2 1- In the nucleus of a cell, the DNA is usually visible as A- a dense region called the nucleolus. B- the nuclear envelope. C- granular material called chromatin. D- condensed bodies called chloroplasts.
Quiz 7.2 2- Two functions of vacuoles are storing materials and helping to A- break down organelles. B- assemble proteins. C- maintain homeostasis. D- make new organelles.
Quiz 2 Section 4-1 3- Chloroplasts are found in the cells of A- plants only. B- plants and some other organisms. C- all eukaryotes. D- most prokaryotes.
Quiz 2 Section 4-1 4- Which of the following is NOT a function of the Golgi apparatus? A- synthesize proteins. B- modify proteins. C- sort proteins. D- package proteins.
Quiz 2 Section 4-1 5- Which of the following is a function of the cytoskeleton? A- manufactures new cell organelles B- assists in movement of some cells from one place to another C- releases energy in cells D- modifies, sorts, and packages proteins
Quiz 2 Section 4-1 6- The cell organelle involved in breaking down other organelles that have outlived their usefulness is the A- lysosome. B- mitochondrion. C- chloroplast. D- Rough ER
Quiz 2 Section 4-1 7. Which structures carry out cell movement? a. cytoplasm and ribosomes b. nucleolus and nucleus c. microtubules and microfilaments d. chromosomes
Quiz 2 Section 4-1 8. Which organelle makes proteins using coded instructions that come from the nucleus? a. Golgi apparatus b. mitochondrion c. vacuole d. ribosome
Quiz 2 Section 4-1 9. Which organelle converts the chemical energy stored in food into compounds that are more convenient for the cell. a. chloroplast b. endoplasmic reticulum c. mitochondrion d. Golgi apparatus
Quiz 2 Section 4-1 10. Which of the following is NOT found in the nucleus? a. chromatin b. nucleolus c. cytoplasm d. DNA
7-3 Cell Boundaries
Cell Boundaries All cells are surrounded by a thin, flexible barrier known as the cell membrane. Many cells produce a strong layer around the membrane known as a cell wall.
Cell Membrane Section 4-1 The cell membrane regulates what enters and leaves the cell and also provides protection and support.
Cell Walls Cell walls are found in plants, algae, fungi, and many prokaryotes.
Diffusion Through Cell Boundaries Section 4-1 Measuring Concentration A solution is a mixture of two or more substances. The substances dissolved in the solution are called solutes. The concentration of a solution is mass of solute in a volume of solution, or mass/volume. 12 grams of salt in 3 liters of water, the concentration of the solution would be 12 g/3 L or 4 g/l (grams per liter)
Diffusion Through Cell Boundaries Section 4-1 diffusion. Particles in a solution move from an area where they are more concentrated to an area where they are less concentrated.
Diffusion Through Cell Boundaries When the concentration of the solute is the same throughout a system, the system has reached equilibrium.
Diffusion Through Cell Boundaries
Osmosis Section 4-1 What is osmosis? Osmosis is the diffusion of water through a selectively permeable membrane. Higher Concentration of Water Water molecules Cell membrane Lower Concentration of Water Sugar molecules
Osmosis
Osmosis How Osmosis Works Concentrated sugar solution (Water less concentrated) Dilute sugar solution (Water more concentrated) Sugar molecules Selectively permeable membrane Movement of water
Osmosis Water tends to diffuse from a highly concentrated region to a less concentrated region. If you compare two solutions, three terms can be used to describe the concentrations: hypertonic ( above strength ). hypotonic ( below strength ). isotonic ( same strength )
Osmotic Pressure Osmosis exerts a pressure known as osmotic pressure on the hypertonic side of a selectively permeable membrane.
Osmotic Pressure
Facilitated Diffusion Only glucose can pass through this channel in either direction. This cell membrane protein is said to facilitate, or help, the diffusion of glucose across the membrane. Glucose High Concentration Cell Membrane Low Concentration Protein
Active Transport Sometimes cells move materials in the opposite direction from which the materials would normally move. This process is known as active transport. Active transport requires energy.
Active transport Small molecules and ions are carried across membranes by proteins in the membrane. Energy is used to enable cells to concentrate substances in a particular location.
Active Transport Endocytosis and Exocytosis Endocytosis is the process of taking material into the cell, by infoldings, or pockets of cell membrane.
Active Transport Two examples of endocytosis are: Phagocytosis cell engulfs a particle. Pinocytosis cell takes in small amounts of liquid and form a vacuole inside cell.
Quiz7.3 1- Unlike a cell wall, a cell membrane A- is composed of a lipid bilayer. B- provides rigid and tough support for the surrounding cell. C- allows all molecules to pass through easily. D- is found only in plants, fungi, algae, and many prokaryotes.
Quiz3 Section 4-1 2- The concentration of a solution is defined as the A- volume of solute in a given mass of solution. B- mass of solute in a given volume of solution. C- mass of solution in a given volume of solute. D- volume of solution in a given mass of solute.
Quiz3 Section 4-1 3- If a substance is more highly concentrated outside the cell than inside the cell and the substance can move through the cell membrane, the substance will A- move by diffusion from inside the cell to outside. B- remain in high concentration outside the cell. C- move by diffusion from outside to inside the cell. D- cause water to enter the cell by osmosis.
Quiz3 Section 4-1 4- The movement of materials in a cell against a concentration difference is called A- facilitated diffusion. B- active transport. C- osmosis. D- diffusion.
Quiz3 Section 4-1 5- The process by which molecules diffuse across a membrane through protein channels is called A- active transport. B- endocytosis. C- facilitated diffusion. D- osmosis.
Quiz3 Section 4-1 6- Equilibrium is reached in a system when the concentration of a solute is A- increasing throughout the system. B- decreasing throughout the system. C- the same throughout the system. D- more than enough on one side
Quiz3 Section 4-1 7- Which plant and bacterial cell structure protects the cells from damage from osmotic pressure? A- cell wall B- cell membrane C- nucleolus D- Golgi
Quiz3 Section 4-1 8- Facilitated diffusion does not require the cell to use energy because A- the molecules themselves supply the needed energy. B- molecules move from low concentration to high concentration. C- molecules move from high concentration to low concentration. D- molecules don t have to move
Quiz3 Section 4-1 9- The main function of the cell wall is to a. direct the activities of the cell. b. support and protect the cell. c. help the cell move. d. store DNA.
Quiz3 Section 4-1 10. Diffusion is the movement of molecules from a. an area of equilibrium to an area of high concentration. b. an area of high concentration to an area of low concentration. c. an area of low concentration to an area of high concentration. d. all of the above
Quiz3 Section 4-1 11. When the concentration of molecules on both sides of a membrane is the same, the molecules will a. move across the membrane to the inside of the cell. b. move across the membrane to the outside of the cell. c. stop moving across the membrane. d. move across the membrane in one directions.
Quiz3 Section 4-1 12. The cell membrane contains channels and pumps that help move materials from one side to the other. What are these channels and pumps made of? a. lipids b. bilipids c. carbohydrates d. proteins
7-4 The Diversity of Cellular Life
The Diversity of Cellular Life The differences among living things are the ways in which cells are specialized to perform certain tasks. Also the ways in which cells associate with one another to form multicellular organisms.
Unicellular Organisms Section 4-1 Made up of only one cell. Unicellular organisms dominate life on Earth.
Multicellular Organisms Organisms that are made up of many cells are called multicellular. There is a great variety among multicellular organisms.
Cell Specialization Cells throughout an organism can develop in different ways to perform different tasks. This process is called cell specialization.
Specialized Animal Cells Animal cells are specialized in many ways. Red blood cells transport oxygen.
Multicellular Organisms Cells in the pancreas produce proteins.
Multicellular Organisms Section 4-1 Muscle cells allow movement.
Multicellular Organisms Specialized Plant Cells Plants exchange carbon dioxide, oxygen, water vapor, and other gases through tiny openings called stomata on the undersides of leaves.
Multicellular Organisms Specialized Plant Cells Highly specialized cells, known as guard cells, regulate this exchange.
Multicellular Organisms Stomata enclosed by guard cells.
Levels of Organization What are the four levels of organization in multicellular organisms? individual cells tissues organs organ systems
Levels of Organization Section 4-1 Levels of Organization Muscle cell Smooth muscle tissue Stomach Digestive system
Levels of Organization In multicellular organisms, cells are the first level of organization.
Levels of Organization Section 4-1 Tissues Similar cells are grouped into units called tissues. A tissue is a group of similar cells that perform a particular function.
Levels of Organization Most animals have four main types of tissue: muscle epithelial nervous connective
Levels of Organization Section 4-1 Organs Organs are groups of tissues that work together to perform a specific function.
Levels of Organization Section 4-1 Organ Systems In most cases, an organ completes a series of specialized tasks.
Levels of Organization Section 4-1 Organ Systems A group of organs that work together to perform a specific function is called an organ system.
Quiz 7.4 1. An organ system is a group of organs that a. work together to perform a specific function. b. are made up of similar tissues. c. work together to perform all the functions in a multicellular organism. d. are made up of similar cells.
Quiz 7.4 2- All of the following are types of tissues EXCEPT a. connective. b. muscle. c. digestive. d. nerve.
Quiz 7.4 3- All of the following are examples of cell specialization EXCEPT a. muscle cells that control all the movement of materials in the body b. a prokaryotic cell that carries out photosynthesis. c. a pancreatic cell that produces proteindigesting enzymes. d. a red blood cell that carries oxygen.
Quiz 7.4 4- The cells of multicellular organisms are a. simpler than those of unicellular organisms. b. not dependent on one another. c. specialized to perform different tasks. d. smaller than those of unicellular organisms.
Quiz 7.4 5- Which of the following is an organ of the digestive system? a. stomach b. nerve tissue c. epithelial tissue d. muscle cell
Quiz 7.4 6- Which term refers to cells having different jobs in an organism? a. multicellular b. levels of organization c. unicellular d. cell specialization
Quiz 7.4 7- Which list represents the levels of organization in a multicellular organism from the simplest level to the most complex level? a. tissue, organ, organ system b. cell, tissue, organ system c. cell, tissue, organ, organ system d. organ system, organ, tissue, cell
Quiz 7.4 8- A group of similar cells that perform a particular function is called a(an) a. organ system. b. organ. c. division of labor. d. tissue.
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