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Life Science

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Title: Life Science


1
Life Science
  • What is the GED Science Test like overall?
  • The GED Science Test requires you to know some of
    the basic science concepts that will be covered
    in this book. You will NOT HAVE TO RECALL
    specific facts or formulas, but you will have to
    draw upon your prior science knowledge.  
  • (pages 457 and 458)

2
Life Science
  • What is the GED Science Test like overall?
  • You will need the skill of distinguishing a
    science fact, name, or term from a principle,
    concept, or law.
  • (pages 457 and 458)

3
Life Science
  • What is the GED Science Test like overall?
  • The context of the Science Test is that of daily
    living or workplace settings and shows you as an
    individual acquirer, organizer, and user of
    information in a lifelong process.
  • (pages 457 and 458)

4
Life Science
  • What is the GED Science Test like overall?
  • It depicts your common roles as an adult,
    including that of a citizen, family member,
    worker, or consumer. The test includes studies of
    relationships between science and technology,
    research, communications, and society.
  • (pages 457 and 458)

5
Life Science
  • What is the GED Science Test like overall?
  • The test acknowledges local and global problems,
    issues, and events, and frequently, the test
    requires problem-solving skills.
  • (pages 457 and 458)

6
Life Science
  • What is the GED Science Test like overall?
  • You will need to be able to show that you can
    comprehend (understand) what you read, apply
    information to a new situation, analyze
    relationships between ideas or concepts, and
    synthesize information from two or more sources.
  • (pages 457 and 458)

7
Life Science
  • What is the GED Science Test like overall?
  • In order to answer the questions successfully,
    you will need to demonstrate that you have the
    general reading competency of a high school
    graduate.
  • (pages 457 and 458)

8
Life Science
  • Whats on the test?
  • The GED Science Test is based on the National
    Science Education Standards (NSES) Scientific
    Understanding Strands and is divided into these
    content areas
  • Life Science (Biology) 45
  • Earth and Space Science 20 
  • Physical Science 35 (Chemistry and Physics)
  • (pages 457 and 458)

9
Life Science
  • How many and what type of questions are on the
    test?
  •  
  • There are 50 multiple-choice questions, and you
    will be given 80 minutes to complete the test.
  • (pages 457 and 458)

10
Life Science
  • How many and what type of questions are on the
    test?
  • Passage sets versus stand-alone questions
  • 1. Approximately 25 (12-13) of the questions are
    based on passage sets. This means that two or
    more questions are based on the same passage or
    the same graphic.
  • (pages 457 and 458)

11
Life Science
  • How many and what type of questions are on the
    test?
  •  Passage sets versus stand-alone questions
  • 2. Approximately 75 (37-38) of the questions
    will be single, stand alone questions. This type
    of question could, for example, state the
    scientific theory and then ask questions based on
    using the theory in a real-life situation.
  • (pages 457 and 458)

12
Life Science
  • How many and what type of questions are on the
    test?
  •  
  • Reading text versus graphics
  •  
  • 1. Approximately 50 (25) of the questions will
    be based on text material.
  • (pages 457 and 458)

13
Life Science
  • How many and what type of questions are on the
    test?
  • Reading text versus graphics
  •  
  • 2. Approximately 50 (25) of the questions will
    be based on visuals graphs, maps, charts, or
    tables, pictures, diagrams, advertisements, or
    political cartoons.
  • (pages 457 and 458)

14
Life Science
  • What themes are represented by the Science
    content?
  • Six themes are reflected in the content
  • 1) The theme Fundamental Understandings
    comprises the majority with 60 (or 30) of the
    test questions.
  • (pages 457 and 458)

15
Life Science
  • What themes are represented by the Science
    content?
  • Six themes are reflected in the content
  • 2) Science in Personal and Social Perspectives
    is the next largest category, with 17 (or 8) of
    the test questions. As you prepare for this
    theme, you should pay particular attention to
    issues relating to the environment and health.
  • (pages 457 and 458)

16
Life Science
  • What themes are represented by the Science
    content?
  • Six themes are reflected in the content
  • 3) The remaining 12 questions are made up of
    these four the themes Unifying Concepts and
    Processes, Science as Inquiry, Science and
    Technology, and History and Nature of Science.
  •  
  • (pages 457 and 458)

17
Life Science
  • What else do I need to know to prepare?
  • Essential science concepts are covered in
    Chapters 1-4 of this section. However, keep in
    mind that a given question may draw from a number
    of these subjects. In discussing science as it
    affects people, it is natural to touch on a
    number of topics.
  • (pages 457 and 458)

18
Life Science
  • What else do I need to know to prepare?
  • We say that the test acknowledges the
    interdisciplinary nature of science. For example,
    a question could involve a daily living situation
    of moving furniture, could use the physics
    principle of the lever (a simple machine) and
    could draw on the skill of multiplication from
    mathematics in order to arrive at pounds of force
    necessary.
  • (pages 457 and 458)

19
Life Science - Biology
  • BiologyThe Study of Living Things
  •  
  • Biology is the scientific study of all life
    forms. Biologists are interested in how living
    things grow, how they change over time, and how
    they interact with one another and with their
    environment. Of particular interest are the
    characteristics that all living things have in
    common.
  • (page 459)

20
Life Science - Biology
  • BiologyThe Study of Living Things
  •  
  • Biology is the scientific study of all life
    forms.
  • All living things react to stimuli, take in food
    and use it to grow, eliminate wastes, and
    reproduce. The starting point for any systematic
    study of biology is an examination of the basic
    unit of life, the cell.
  • (page 459)

21
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • The cell is the smallest unit of living material
    capable of carrying on the activities of life.
    Like the bricks of a building, cells are the
    "building blocks" of an organism. Cells were
    first observed in 1665 by Robert Hooke with the
    aid of a crudely made microscope.
  • (page 459)

22
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Cells vary widely in size and appearance. It is
    the number of cells in an organism, however, and
    not the size of cells, that determines the size
    of an organism. The cells of a human being and a
    whale are of equal size. The whale is larger
    because its genetic pattern dictates that a
    larger number of cells be produced.
  • (page 459)

23
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Types of Cells
  • Two kinds of cells are known to existplant cells
    and animal cells. Cells are responsible for the
    exchange of food and wastes within the organism.
    Inside of all cells are the structures that
    provide the specific jobs needed for these
    exchanges.  
  • (page 459)

24
Life Science - Biology
  • BiologyThe Study of Living Things
  • Types of Cells
  • One difference between the two is that a plant
    cell has a cell wall that protects it and an
    animal cell does not. Also, plant cells contain
    chloroplasts, structures active in the
    food-making process, while animal cells do not.
  •  
  • (page 459)

25
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life

26
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life

27
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life

28
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Types of Cells
  • Both plant and animal cells are surrounded by a
    delicate boundary, the cell membrane. The cell
    membrane
  • preserves the cell by acting as a barrier
    between it and the outside environment
  • helps the cell maintain its shape
  • regulates molecular traffic passing into and
    out of the cell (page 459)

29
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  •  
  • A highly specialized and complex structure, the
    cell has its own control center, transportation
    system, power plants, factories for making needed
    materials, and even a reproductive blueprint, or
    chemical recipe.
  • (page 460)

30
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Vocabulary
  • Proteins A macromolecule composed of one or
    several polypeptides
  • Polypeptides A molecule composed of amino acids
    linked together by peptide bonds
  • Peptide bonds A bond that joins two amino acids
  • (page 460)

31
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Vocabulary
  • Amino Acid A unit of protein
  • Carbohydrates Substance in foods such as rice,
    bread, and potatoes that provides the body with
    heat and energy.
  • Chromosome - genetic blueprint for the cell
  • (page 460)

32
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Vocabulary
  • DNA A nucleic acid, the genetic material that
    directs protein synthesis in the cell
  • Genes Part of the cell that controls its growth
  • RNA - A nucleic acid, important in the synthesis
    of protein
  • (page 460)

33
Life Science - Biology
  • DNA A nucleic acid, the genetic material that
    directs protein synthesis in the cell

34
Life Science - Biology
  • RNA - A nucleic acid, important in the synthesis
    of protein

35
Life Science - Biology
  • DNA - Fingerprint

36
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Parts of the Cell
  • Cytoplasm - protoplasm found between the nuclear
    membrane and the cell membrane (the body of the
    cell). (page 460)

37
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Parts of the Cell
  • Endoplasmic reticulum - a tubular transport
    system within the cell or to the outside
    (Synthesis proteins and other substances) 
  • (page 460)

38
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Parts of the Cell
  • Mitochondrion - power plant inside cell which
    produces energy for cellular function plural is
    mitochondria (cellular respiration) (page 460)

39
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Parts of the Cell
  • Golgi apparatus - the packaging plant, which
    gathers proteins and carbohydrates in membraneous
    sacs in gland cells it releases hormones to the
    rest of the body (page 460)

40
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Parts of the Cell
  • Nucleus - the control center for the cell,
    surrounded by a double nuclear membrane it
    contains the chromosome or genetic blueprint for
    the cell (page 460)

41
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Parts of the Cell
  • Chromosome - the genetic blueprint found in the
    nucleus it contains DNA that makes up the genes,
    which are the genetic code for the cells, organs,
    and structure of the body  (page 460)

42
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Parts of the Cell
  • Nucleolus - the holding tank for RNA, the
    essential acid for the chemical activity of the
    cell and the chromosome information that permits
    the manufacture of protein (page 460)

43
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • EXERCISE 1
  • Cell Structure
  • Directions Match each term on the right with the
    mechanical function it performs on the left.
    Write the letter of the correct term in the space
    provided.
  • (page 461)

44
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • EXERCISE 1
  • Cell Structure
  • 1. ______ regulator of traffic passing into and
  • out of the cell a. nucleus
  • 2. ______ control center for the cell b.
    endoplasmic reticulum
  • 3. ______ means of transportation for material
  • within the cell c. cell membrane
  • 4. ______ factory in which RNA ingredients are
  • assembled and stored d. nucleolus 
  • (page 461)

45
Life Science - Biology
  • BiologyThe Study of Living Things
  • EXERCISE 2
  • Cells
  • Directions Choose the best answer for each of
    the following questions.
  • 1. What is the main idea of the informational
    text?
  • (1) All living things are made of cells.
  • (2) The nucleus is the control center of the
    cell.
  • (3) There are differences between plant and
    animal cells.
  • (4) The cell is an organized structure with
    subsystems.
  • (5) The Golgi apparatus functions as a packaging
    plant in the cell. (page 462)

46
Life Science - Biology
  • BiologyThe Study of Living Things
  • EXERCISE 2
  • Cells
  • 2. In plant cells, chloroplasts are active in
    the chemical processes required to make food.
    Animal cells have no chloroplasts. On this basis,
    what can we conclude?
  • (1) Plant cells are more complex than animal
    cells.
  • (2) Plant cells and not animal cells generate
    chemical reactions.
  • (3) Animal cells prey upon plant cells as a food
    source.
  • (4) Animal cells are more complex than plant
    cells.
  • (5) Animals must obtain food from outside
    sources. (page 462)

47
Life Science - Biology
  • BiologyThe Study of Living Things
  • EXERCISE 2
  • Cells
  • 3. According to the text, mitochondria are the
    power plants that produce energy for important
    life processes in the animal cell and are
    responsible for cellular respiration. What part
    of a plant cell serves a similar function?
  • (1) the cell wall
  • (2) the nucleus
  • (3) the nucleolus
  • (4) the chromosome
  • (5) the chloroplast
  • (page 462)

48
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Cells and Active Transport
  • Every cell has a membrane that selectively
    permits the passage of certain molecules in and
    out of the cell. The movement of molecules
    through the cell membrane without any effort on
    the cell's part is achieved by diffusion.
  • (page 462)

49
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Cells and Active Transport
  • Diffusion is the movement of molecules from an
    area of high concentration to an area of low
    concentration. Vibrating molecules are propelled
    away from one another after they collide. It is
    through this process that odors can fill a large
    room in a short period of time.  
  • (page 462)

50
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Cells and Active Transport
  • Diffusion

51
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Cells and Active Transport
  • Diffusion

52
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Cells and Active Transport
  • Diffusion is important in higher organisms. In
    the human body, for example, oxygen moves from
    the air sacs in the lungs through cell membranes
    and into the blood through diffusion.
  • (page 462)

53
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Cells and Active Transport
  • A cell's cytoplasm contains many substances in
    varying degrees of concentration. These
    concentrations differ sharply from those in the
    fluid surrounding the cell. Such differences are
    so essential that the cell can die if the
    differences are not maintained. 
  • (page 462)

54
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Cells and Active Transport
  • Given the opportunity, diffusion would quickly
    eliminate these critical differences. Therefore,
    the cell must be able to negate, and sometimes
    even reverse, the process of diffusion. This is
    accomplished by active transport. During active
    transport, the cell moves materials from an area
    of low concentration to an area of high
    concentration. This work requires energy.(page
    462)

55
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Exercise 3
  • Cells and Active Transport
  • Directions In the blank spaces below, write the
    words that correctly complete each of the
    following statements.
  •  
  • (page 463)

56
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Exercise 3
  • Cells and Active Transport
  •  
  • 1. Diffusion is the movement of molecules from
    an area of _____________ concentration to an area
    of _______ concentration.
  • (page 463)

57
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Exercise 3
  • Cells and Active Transport
  • 2. In active transport, materials are moved
    from an area of
  • _______ concentration to an area of _______
    concentration.
  •  
  • (page 463)

58
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Exercise 4
  • Diffusion and Osmosis
  •  
  • Directions Choose the best answer for each of
    the following questions.
  •  
  • (page 463)
  •  
  •  

59
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Exercise 4
  • Diffusion and Osmosis
  • 1. How does the process of diffusion function
    in the human body?
  • (1) It allows for concentrations of materials,
    where needed, in the body, through stockpiling.
  • (2) It regulates blood flow between organs
    through veins and arteries.
  • (3) It allows an even distribution of substances
    throughout all cells of the body.
  • (4) It comes into play in times of extreme
    illness and stress.
  • (5) It plays an insignificant role in the body's
    functioning.
  • (page 463)

60
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Cell, the Basic Unit of Life
  • Exercise 4
  • Diffusion and Osmosis
  • 2. Osmosis may be described as a process
    through which water in a solution is able to move
    through the cell membrane from a higher
    concentration to a lower one in order to maintain
    balance on either side of the membrane. If the
    salt solution in blood plasma surrounding red
    blood cells is higher than the solution inside
    the cells, which is most likely to occur?
  • (1) Water will leave the cell and pass into the
    blood plasma.
  • (2) Water will leave the blood plasma and pass
    into the cell.
  • (3) The cell will expand because of a gain in
    water.
  • (4) The cell will carry on respiration at a
    slower rate.
  • (5) Cellular division starts to try to save the
    cell. 
  • (page 463)

61
Life Science - Biology
  • DNA AND CHROMOSOMES
  • (page 464)

62
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division
  • Active cell transport requires energy. Energy is
    also needed for the growth of an organism. As a
    cell grows, its cell membrane becomes less able
    to provide oxygen and nutrients for the interior
    of the cell, and wastes become unable to leave
    the cell. In addition, a nucleus can control only
    so much cytoplasm. Therefore, when a cell reaches
    its limit in size, it must divide or undergo a
    process called mitosis.
  • (page 464)

63
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division
  • Mitosis is the process through which cells
    reproduce themselves by division. In a
    multicellular organism mitosis leads to tissue
    growth and maintenance. In a single-celled
    organism mitosis results in two new genetically
    identical independent organisms. Mitosis can be
    divided into four stages or phases, as shown in
    the diagrams.
  •  
  • (page 464)

64
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division

65
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division
  •  Stage 1 Prophase - Just before prophase begins,
    genetic material in the nucleus is duplicated
    (doubled). Then the nuclear membrane and
    nucleolus disappear. The chromosomes (genetic
    material) shorten, visible centrioles appear at
    opposite ends of the cells, and small fibers
    start to form between them.
  • (page 465)

66
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division
  • Stage 2 Metaphase - During metaphase the spindle
    fibers attach themselves to the center of the
    chromosomes (centromeres). The chromosomes are
    now quite thick and visible. They begin to line
    up at the equator of the cell.
  •  
  • (page 465)

67
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division
  • Stage 3 Anaphase - During anaphase, the
    centromeres divide, and the duplicate pairs of
    chromosomes separate. The separate pairs then
    move toward the poles of the cell.
  •  
  • (page 465)

68
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division
  •  
  • Stage 4 Telophase - When the chromosomes arrive
    at the poles, telophase begins. The nuclei
    re-form, the chromosomes gradually become less
    visible, and the cell separates to form two new
    cells. The daughter cells are genetically and
    physically identical to the parent cell except
    for size.
  • (page 465)

69
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division
  • In single-cell organisms cell division results in
    the creation of two new individuals. In complex
    organisms (made of more than one cell) the new
    daughter cells form a subsystem of the parent
    cell. In many organisms cell reproduction is at
    its peak while the organism grows. As the
    organism ages, the process is limited to the
    replacement of old and damaged cells.
  • (page 465)

70
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division

71
Life Science - Biology
  • BiologyThe Study of Living Things
  • MitosisCell Division
  • EXERCISE 5
  • Mitosis
  • Directions Match each phase of mitosis on the
    left with its description on the right.
  • 1. _______ Prophase (a) The chromosomes become
    easily visible.
  • 2. _______ Metaphase (b) The chromosomal material
    lines up at the center of the cell.
  • 3. _______ Anaphase (c) The cell divides to form
    two new cells.
  • 4. _______ Telophase (d) The pairs of
    chromosomes move to opposite poles.
  • (page 465)

72
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • While mitosis involves general cell division, a
    special type of cell division for reproductive
    purposes is called meiosis. Meiosis is a process
    in which a parent cell undergoes two special
    types of cell division that result in the
    production of four gametes (reproductive cells).
  • (page 466)

73
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division 
  • Each gamete has half the number of chromosomes of
    the original parent cell. Each organism has a
    chromosome number that is characteristic of that
    organism. For example, all of the cells in the
    human body contain 46 chromosomes except for the
    gametes (the reproductive cells). (page 466)
  •  

74
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • The reproductive cells (sperm and egg) cannot
    carry the same number of chromosomes as those of
    other parts of the body. If they did, the
    offspring that would result from the union of the
    egg and sperm would have twice the normal amount
    of genetic material after cell division. (page
    466)

75
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • In animals this doubling would result in the
    termination of the embryo early in development.
    To prevent termination, the sex cells undergo
    meiosis, a special division process.
  • (page 466)
  •  

76
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • Meiosis I The chromosome pairs come together to
    exchange genes. This process is crossed crossing
    over. Crossing over ensures a recombination of
    genetic material. Later the pairs separate, and
    one chromosome of each pair moves to a new cell.
    During telophase 1, the cytoplasm divides, and
    the two daughter cells are formed. Each daughter
    cell is called a haploid cell, a cell that
    contains half the number of chromosomes of the
    original parent cell.(page 466)

77
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • Meiosis I (page 466)

78
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • Meiosis I (page 466)

79
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • Meiosis II - (Note Only one daughter cell from
    Meiosis I is shown here.) (page 467)

80
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • Meiosis II
  • In Meiosis II the chromosomal material combines,
    separates, and moves to new cells, resulting in
    four reproductive cells. In human beings, when
    two haploid cells (a sperm and an egg, each
    containing 23 chromosomes) unite in
    fertilization, they form a diploid cell, a cell
    containing 46 chromosomes. The fertilized cell
    contains 46 chromosomes, or 23 pairshalf from
    the mother and half from the father. (page 467)

81
Life Science - Biology
  • BiologyThe Study of Living Things
  • MeiosisReproductive Cell Division
  • Exercise 6  
  • Meiosis
  • Directions Number the steps in meiosis in the
    order in which they occur.
  •  
  • ____ Two new cells divide, resulting in four
    reproductive cells.
  •  
  • ____ Chromosomes come together in pairs.
  •  
  • ____ Chromosome pairs separate, and each
    chromosome moves to a new cell.
  •  
  • ____ Chromosomes exchange genes.
  •  
  • (page 467)

82
Life Science - Biology
  • BiologyThe Study of Living Things
  • Cell Division
  • Exercise 7
  • Directions Choose the best answer for each of
    the following questions. 
  • 1. Which method of reproduction provides for
    the most variety in offspring?
  • (1) asexual (nonsexual) reproduction genetic
    information from a single parent to offspring
  • (2) mutative reproduction occasional mutation of
    a cell changing the organism's appearance
  • (3) sexual reproduction exchange of genetic
    information from two parents
  • (4) cloning duplication of genetic information
    of a single organism
  • (5) cellular reproduction cell division into two
    cells
  • (page 468)

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  • BiologyThe Study of Living Things
  • Cell Division
  • Exercise 7 
  • 2. Cancer is a condition in which cells that
    serve no function in the body invade healthy
    ones. On this basis, what can we conclude about
    malignant cancer cells?
  • (1) They do not reproduce by mitosis.
  • (2) They divide by meiosis.
  • (3) They divide more unpredictably than normal
    cells.
  • (4) They divide less frequently than benign
    cells.
  • (5) They are parasites and do not reproduce by
    division at all. 
  • (page 468)

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  • BiologyThe Study of Living Things 
  • Genetics and Heredity
  • Heredity is the term used to describe the passing
    of traits from parents to children. Every species
    has its own set of traits that it transmits to
    its offspring. Genetics is the study of how
    traits are passed on. Geneticists, the scientists
    who study heredity, have found that hereditary
    information of an organism is carried by the
    chromosomes of the cell nucleus.
  • (page 469)

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  • BiologyThe Study of Living Things
  • Genetics and Heredity
  • Genes determine all of our inherited traits.
    Every human being receives two genes for each
    traitone from the mother and one from the
    father. Genes may be dominant or recessive. The
    dominant gene, if present, will always appear in
    an offspring. For example, because brown eye
    color is a dominant trait, 90 percent of human
    beings have brown eyes. If two dominant genes are
    inherited, the resulting trait will be a
    combination of the two inherited characteristics.
    (page 469)

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  • BiologyThe Study of Living Things
  • Genetics and Heredity
  • Sexual reproduction ensures that the offspring
    has genetic material from both parents. This
    genetic material is thoroughly remixed with every
    fertilization so that, with the exception of
    identical twins, no two offspring of the same
    parents are exactly alike genetically.
  •  
  • (page 469)

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  • BiologyThe Study of Living Things
  • Sex and Mutations
  • Whether a mother gives birth to a boy or girl is
    determined by the X and Y chromosomes. A person
    receives two sex chromosomesone from the
    father's sperm cell and one from the mother's egg
    cell. Egg cells contain a single X chromosome.
    Male sperm cells may contain either an X or a Y
    chromosome. If two X chromosomes unite, a female
    will be created. If the sperm reaching the egg
    has a Y chromosome, a male will be produced. The
    sperm cells, then, carry the chromosome that
    determines the sex of offspring.
  •  (page 469)

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  • BiologyThe Study of Living Things
  • Sex and Mutations
  • Sometimes a mistake occurs in the genetic makeup
    of a chromosome during cell duplication. This
    change in the genes, called a mutation, may be
    passed on to offspring. Two mutations in humans
    are Down's Syndrome, which results in brain
    damage, and muscular dystrophy, a disease that
    causes muscles to waste away.
  •  
  • (page 469)

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Life Science - Biology
  • BiologyThe Study of Living Things
  • Exercise 8
  • Genetics and Heredity
  • Directions Study the diagram and choose the
    best answer for the questions that follow.
  •  

90
Life Science - Biology
  • BiologyThe Study of Living Things
  • Exercise 8
  • Genetics and Heredity
  • 1. According to the diagram, what percentage of
    this couple's children might have blue eyes?
  • (1) 75 percent
  • (2) 50 percent
  • (3) 0 percent
  • (4) 25 percent
  • (5) 100 percent
  • (page 470)

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  • BiologyThe Study of Living Things
  • Exercise 8
  • Genetics and Heredity
  • The following question is not based on the
    preceding diagram.
  • 2. The Jones family has had four children, all
    girls. Their fifth child is a boy. Why did this
    change occur?
  • (1) the conception classes taken by the parents
  • (2) the timing of the fertility cycles
  • (3) the father's contribution of a Y chromosome
  • (4) the mother's contribution of a Y chromosome
  • (5) the "law of averages" finally catching up
  • (page 470)

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  • BiologyThe Study of Living Things
  • Cloning

93
Life Science - Biology
  • BiologyThe Study of Living Things
  • Cloning
  • Until the mid-1990s, reproduction involved the
    contribution of genetic material from two parent
    organisms. In 1996 in Scotland, a sheep named
    Dolly was created by a process that is called
    cloning. The egg cell (whose nucleus had been
    removed) from an adult sheep was "fertilized"
    with the nucleus of a mature female mammary cell.
  • (page 471)

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  • BiologyThe Study of Living Things
  • Cloning
  • The developing embryo had the full genetic
    information from a single adult and was
    considered a clone of the adult from which the
    mammary nucleus had come. Cloning human
    individuals has many moral and ethical issues
    regarding whether it is right or wrong to
    "interfere" with the natural reproductive
    process. These issues have prevented researchers
    from pursuing experiments dealing with people.
  • (page 471)

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  • BiologyThe Study of Living Things
  • Cloning

96
Life Science - Biology
  • BiologyThe Study of Living Things
  • EXERCISE 9
  • Cloning
  • Directions Mark the following statements about
    cloning as being true (T) or false (F).
  • 1. ______ Scientists are working on ways to clone
    a deceased child.
  • 2. ______ A clone has two parents but looks like
    only one of them.
  • 3. ______ The first sheep to be cloned was
    created in the United States.
  • 4. ______ A cloned organism still must go through
    the development of an embryo.
  • 5. ______ The egg cell that is used for a clone
    must have the original nucleus removed.
  • (page 472)

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Life Science - Biology
  • BiologyThe Study of Living Things
  • Organ Systems 
  • Once an organism has successfully completed the
    reproductive process, the newly developing
    offspring's cells begin specializing into what
    will become the variety of internal organs. The
    human body is made up of several organ systems
    that specialize in functions that are necessary
    for an organism to thrive. The nervous system is
    made up of the brain, the spinal cord, and nerve
    cells. The circulatory system is in charge of
    circulating the blood from the heart through a
    series of arteries, veins, and capillaries (small
    connecting vessels).
  •  (page 473)

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  • BiologyThe Study of Living Things
  • Organ Systems
  • The circulatory system works very closely with
    the respiratory system, using blood cells to
    exchange oxygen and carbon dioxide through the
    lungs. Nutrients are distributed and wastes are
    removed from the human body by the digestive and
    excretory systems. All of these systems are able
    to maintain their form and position in the human
    body because of the skeletal and muscular
    systems.
  • (page 473)

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Life Science - Biology
  • BiologyThe Study of Living Things
  • Organ Systems 
  • EXERCISE 10
  • Organ Systems
  • Directions Match each health concern on the left
    with the correct system on the right.
  • 1. ______ ulcer a. nervous system
  • 2. ______ cough b. circulatory system
  • 3. ______ broken arm c. muscular system
  • 4. ______ heart attack d. digestive system
  • 5. ______ migraine headache e.
    respiratory system
  • 6. ______ muscle cramp f. skeletal system
  • (page 473) 

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  • BiologyThe Study of Living Things
  • The Nervous System
  • The nervous system is the means of communication
    of the body and contains the brain, the spinal
    cord, and specialized neurons. The brain is
    divided into two hemispheres, each of which is
    responsible for different but overlapping
    functions. If a portion of the brain is injured
    in an accident, another region can often be
    trained to compensate for the nonfunctioning
    area.
  •  
  •  (page 474)

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  • BiologyThe Study of Living Things
  • The Nervous System
  •  (page 474)

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Life Science - Biology
  • BiologyThe Study of Living Things
  • The Nervous System
  • Speech, Sight, and Visual Memory
  • People who have had strokes or severe concussions
    may lose the ability to use the speech center in
    the brain located in the area called the temporal
    lobe, found near the temples. Another lobe is
    called the occipital. This lobe is located in the
    back of the brain and is in charge of sight. If
    you hit the back of your head the stimulus to
    this section of the brain is responsible for your
    "seeing stars." The optic nerve in the eye
    connects to the occipital lobe of the brain,
    where images projected on the retina (the back
    wall of the eye ball) are recorded and evaluated.
    This part of the brain also is in charge of
    visual memory. (page 474)

103
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  • BiologyThe Study of Living Things
  • The Nervous System
  • Speech, Sight, and Visual Memory
  • If you were to be asked how many windows are on
    the front of your home or the total number of
    windows you had in your home, you would count the
    windows by visualizing them in your mind. This
    ability to visualize is also called photographic
    memory.
  •  
  • (page 474)

104
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  • BiologyThe Study of Living Things
  • The Nervous System
  • Voluntary and Involuntary Functions
  • (page 474)

105
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  • BiologyThe Study of Living Things
  • The Nervous System
  • Voluntary and Involuntary Functions
  • The brain has both voluntary and involuntary
    levels of function. The portion of the brain that
    controls voluntary functions is referred to as
    the cerebrum. It controls all motor coordination
    and interpretation of sensory information from
    inside and outside the body. If the temperature
    outside the body is cold, the brain receives the
    information from the sensory neurons in the skin.
    The message is relayed to the brain, which acts
    on the information. You might react to this
    message by adding more clothing or moving to a
    warmer area. (page 474)

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  • BiologyThe Study of Living Things
  • The Nervous System
  • Voluntary and Involuntary Functions
  • The message to move comes from the cerebrum, but
    the cerebellum is the large part of the brain
    that coordinates the actual movements of the
    muscles. The cerebellum is in charge of
    involuntary muscle action, so a new skill or
    newly learned sport involves teaching the
    cerebellum how to coordinate the acquired
    movements. This is also the region that is
    responsible for personality and for
    decision-making. If the cerebellum is injured,
    the personality of the victim may be dramatically
    altered.
  • (page 475)

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  • BiologyThe Study of Living Things
  • The Nervous System
  • Voluntary and Involuntary Functions
  • Passive or shy people have been known to become
    very hostile and verbal, while people with
    outgoing personalities have become withdrawn and
    introverted. One such documented case involved a
    railway worker, Phineaus Gage. While supervising
    at a site he was struck with a metal spike that
    went through his cheek and up and out of his
    cerebellum. Surprisingly, the injuries were not
    fatal, but he became very aggressive and
    short-tempered and was no longer able to be in a
    position of authority. (page 475)

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  • BiologyThe Study of Living Things
  • The Nervous System
  • Voluntary and Involuntary Functions 
  • Another subconscious portion of the brain is the
    medulla oblongata, located in the back of the
    brain. It governs involuntary body functions like
    breathing and digestion. The neurons are located
    everywhere throughout the body and are
    responsible for taking messages to and from the
    brain to the organs and the muscles. The motion
    of your diaphragm, which draws in air, and the
    peristalsis or movement of food through the
    digestive tract are both examples of how the
    medulla regulates involuntary systems. (page 475)

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  • The Nervous System

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  • The Nervous System

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  • BiologyThe Study of Living Things
  • The Nervous System
  • Spinal Cord and Message Transport
  • The spinal cord is the long system of nerves that
    travels down the spine from the brain. At times
    the spinal cord acts as a body defense system
    that prevents injury by immediately acting on an
    emergency nerve-cell message. This immediate
    response, called a reflex, is used when the
    message going to the brain and out to the trauma
    area would take too long. An example is your hand
    coming into contact with a hot material. Your
    reflex response is to remove the hand before the
    brain has even had time to register and evaluate
    the situation. Blinking is another example of how
    a reflex helps protect sensitive areas, such as
    the eyes. (page 475)

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  • BiologyThe Study of Living Things
  • The Nervous System
  • Spinal Cord and Message Transport
  • In the case of spinal injury, the messages
    relayed from the brain might not be able to
    travel the spinal cord to the muscle site. This
    injury is referred to as paralysis. The muscles
    do not act if they cannot receive the message
    from the brain. As a person ages, the bones lose
    strength. In the case of the spinal column, the
    individual vertebrae may move and pinch the
    spinal cord. This action can be very painful and
    may cause temporary paralysis. Doctors may advise
    surgery for the patient to fuse vertebrae
    together to prevent slippage. (page 476)

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  • BiologyThe Study of Living Things
  • The Nervous System
  • Spinal Cord and Message Transport
  •  
  • It is recommended that we maintain calcium in our
    diets to keep bones strong. As we age, we are
    also advised to exercise to strengthen the back
    muscles in order to relieve stress on the spinal
    vertebrae. (We are also reminded to use our leg
    muscles to help us lift objects.)
  • (page 476)

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  • BiologyThe Study of Living Things
  • The Nervous System
  • Spinal Cord and Message Transport
  •  
  • (page 476)

115
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  • BiologyThe Study of Living Things
  • EXERCISE 11
  • The Nervous System
  •  Directions Answer the following questions based
    on what you have learned about the nervous
    system.
  •  1. Which region of the brain would be in
    control of the following activities in the human
    body?
  • a. _____________________ muscle coordination and
    skill in playing sports
  • b. _____________________ a reflex to put hands up
    to block an object from hitting the face
  • c. _____________________ automatic increased
    heart rate while doing exercises
  • d. _____________________ thinking of what tasks
    need to be done at work (page 477)

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  • BiologyThe Study of Living Things
  • EXERCISE 11
  • The Nervous System
  •  
  • 2. Identify the following statements as true or
    false.
  •  
  • _______ The cerebrum controls reflex response.
  • _______ Photographic memory relies on memory in
    the occipital lobe. 
  • _______ Voluntary functions such as walking are
    controlled by the cerebrum.
  • _______ There are four hemispheres in the brain.
  •  (page 477)

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Life Science - Biology
  • BiologyThe Study of Living Things
  • The Nervous System
  • Writing Activity 1
  • Sometimes the functioning of the brain is
    negatively affected by injury or drug use. Some
    conditions of brain dysfunction have a possible
    genetic component like Alzheimer's disorder.
    Write about someone you know who has had a
    condition where the brain was not fully
    functioning. What was the treatment given to that
    patient? If you do not know of anyone who has
    suffered with any of these conditions, can you
    imagine how your life might change if something
    like this happened to you or a family
    member?(page 477)

118
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  • BiologyThe Study of Living Things
  • The Circulatory System
  • The circulatory system has the job of
    transporting nutrients to the cells and removing
    the cell's waste. It does this by means of a
    system of vessels called arteries, veins, and
    capillaries. These vessels provide the pathway
    for the carriers of the nutrients and waste the
    blood cells. (page 478)

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  • BiologyThe Study of Living Things
  • The Circulatory System
  • When the blood cells are pumped out of the heart
    through arteries, they are rich with oxygen,
    having just returned from the lungs. These blood
    cells are squeezed tightly in single file through
    the capillaries where the actual exchange of
    gases into and out of the cells occurs. The route
    back to the heart takes the blood cells by way of
    the veins.
  • (page 478)

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  • BiologyThe Study of Living Things
  • The Circulatory System
  • When in the heart, the blood receives an extra
    push to get it to the lungs, where it releases
    the carbon dioxide from the cell and receives new
    oxygen. The heart is the main pump for this flow
    of cells. (page 478)
  •  

121
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  • BiologyThe Study of Living Things
  • The Circulatory System
  • There are four chambers in the heart. The two
    smaller chambers that receive blood are called
    the atria. The two lower chambers are called the
    ventricles. The pulse from these lower chambers
    is responsible for sending the blood to the next
    location. The heart has a complex series of
    valves at the opening of each chamber in the
    heart. These valves are oneway doors to prevent
    blood from flowing backwards into the previous
    chamber. The heart itself has many small
    capillaries that feed its own muscular walls.
  • (page 478)

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  • BiologyThe Study of Living Things
  • The Circulatory System
  • Depending on a person's diet and lifestyle, these
    small vessels may become clogged with a material
    called plaque. The plaque attaches to the walls
    of the capillary and to clumps of plaque that
    already exist. When the capillaries cannot make
    the exchange of gases or feed the heart muscle, a
    section of the heart starves, undergoing damage
    that could cause a heart attack. (page 478)
  •  

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  • BiologyThe Study of Living Things
  • The Circulatory System
  • Doctors recommend that people be aware of how
    easily their bodies might create plaque using
    cholesterol found in their diet. Treatments can
    include medication, change in exercise and diet,
    expansion of the clogged vessel with a balloon
    device (an angioplasty procedure), or bypass or
    replacement surgery.
  • (page 478)

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Life Science - Biology
  • BiologyThe Study of Living Things
  • Cholesterol
  • Cholesterol is found in the cell membranes and
    transported in the blood plasma of all animals.
    It is an essential component of mammalian cell
    membranes.
  • Although cholesterol is essential for life, high
    levels in circulation are associated with
    atherosclerosis. It is the main precursor of
    vitamin D and of the steroid hormones, which
    include cortisol and aldosterone (in the adrenal
    glands) and progesterone, estrogens, and
    testosterone (the sex hormones), and their
    derivatives.

125
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  • BiologyThe Study of Living Things
  • Cholesterol
  • LDL (low-density lipoprotein) is referred to as
    "bad cholesterol", on the other hand,
    high-density lipoprotein (HDL) is referred as
    good cholesterol. Having large numbers of large
    HDL particles correlates with better health
    outcomes.

126
Life Science - Biology
  • BiologyThe Study of Living Things
  • Cholesterol
  • Animal fats are complex mixtures of
    triglycerides, with lesser amounts of
    phospholipids and cholesterol. Consequently all
    foods containing animal fat contain cholesterol
    to varying extents. Cholesterol is not present in
    plant based food sources unless it has been added
    during the food's preparation. However plant
    products such as flax seeds and peanuts contain
    healthy cholesterol-like compounds called
    phytosterols, which are suggested to help lower
    serum cholesterol levels.

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  • The Circulatory System
  • (page 478)

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  • The Circulatory System
  • (page 478)

129
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  • Respiratory System
  •  
  • (page 479)

130
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  • BiologyThe Study of Living Things
  • Respiratory System
  •  
  • (page 479)

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  • BiologyThe Study of Living Things
  • Respiratory System
  • The respiratory system involves the exchange of
    the outgoing carbon dioxide from the cells with
    the incoming air. This exchange takes place in
    the lungs, which are able to exchange gases
    through small spongelike sacs called alveoli.
    Carbon dioxide and oxygen diffuse in and out of
    the cells to the alveoli and are transported
    inside and outside the body through the
    branchlike system of bronchiole. The bronchiole
    connect to the trachea or wind pipe and release
    breath through the mouth and nose. (page 479)
  •  

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  • BiologyThe Study of Living Things
  • Respiratory System
  •  
  • In those people who smoke, the particles of tar
    that are inhaled become trapped in these small
    sacs. This condition or irritation in the lung
    makes the lungs much less soft and flexible than
    those of nonsmokers. The lung tissue loses the
    flexibility necessary when breathing needs to be
    accelerated (such as during exercise or when
    fighting off infections such as pneumonia). (page
    479)

133
Life Science - Biology
  • BiologyThe Study of Living Things
  • EXERCISE 12
  • The Circulatory and Respiratory Systems
  •  Directions For each of the following questions,
    choose the best answer based on the information
    above.
  • 1. Which part of the respiratory system is
    responsible for the actual exchange of oxygen and
    carbon dioxide?
  • (1) the trachea
  • (2) the alveoli
  • (3) the windpipe
  • (4) the lungs
  • (5) the bronchiole 
  • (page 480)

134
Life Science - Biology
  • BiologyThe Study of Living Things
  • EXERCISE 12
  • The Circulatory and Respiratory Systems
  • 2. Which of the following are parts of the heart
    (H) and which are vessels (V)?
  •  
  • ________ atria
  • ________ capillaries
  • ________ veins
  • ________ ventricles
  • ________ arteries
  • (page 480) 

135
Life Science - Biology
  • BiologyThe Study of Living Things
  • EXERCISE 12
  • The Circulatory and Respiratory Systems
  • 3. Which of the following behaviors would be
    beneficial for the circulatory and respiratory
    systems?
  • (1) smoking cigarettes
  • (2) eating fried foods
  • (3) exercising strenuously
  • (4) painting in unventilated areas
  • (5) exercising moderately daily
  • (page 480)

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Life Science - Biology
  • BiologyThe Study of Living Things
  • The Digestive and Excretory Systems
  • Digestion is the breakdown of food into simple
    molecules so it can be absorbed into the cells.
    Digestion begins when food enters the mouth. The
    action of chewing the food while it is being
    mixed with saliva starts the breakdown. The
    stomach continues the chemical breakdown using
    gastric acids. The food then travels to the small
    intestine, which is in charge of absorbing the
    digested nutrients. (page 481)

137
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  • BiologyThe Study of Living Things
  • The Digestive and Excretory Systems
  • The pancreas, the gall bladder and the liver each
    focus its digestive enzyme on specific food
    chemicals. The small intestine connects the
    stomach to the large intestine (also called the
    colon). The large intestine is next in line with
    the job of absorbing water that is remaining in
    the digested food. It also stores the waste
    material until it is expelled from the body.
  • (page 481)

138
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  • The Digestive and Excretory Systems
  • (page 481)

139
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  • BiologyThe Study of Living Things
  • The Digestive and Excretory Systems
  • (page 481)

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  • BiologyThe Study of Living Things
  • The Digestive and Excretory Systems
  • The digestive system uses enzymes which are
    chemically very acidic. These acids are produced
    when a stimulus (such as food) is present or can
    be produced in response to stress. When they are
    produced in the stomach and there is no food for
    them to digest, acids may have a digestive effect
    on the stomach's protective mucous lining. The
    area that has been damaged by the acids is called
    an ulcer. (page 481)

141
Life Science - Biology
  • BiologyThe Study of Living Things
  • The Digestive and Excretory Systems
  • Several common regions in the digestive tract may
    be susceptible to this condition. Acids can also
    churn at the connection from the stomach to the
    esophagus (the tube from the mouth to the
    stomach). This is a sensitive area that is not
    used to having contact with digestive acids. A
    person with this condition is said to be
    suffering from acid reflux. The sharp pain in the
    chest area may be confused with the symptoms of a
    heart attack. (page 481)

142
Life Science - Biology
  • BiologyThe Study of Living Things
  • EXERCISE 13
  • The Digestive and Excretory Systems
  • Directions Match the definitions on the left
    with the correct terms on the right from the
    reading.
  • 1. ________ acidic chemicals used to digest a.
    large intestine
  •  
  • 2. ________ tube from mouth to stomach b.
    enzymes
  •  
  • 3. ________ portion of digestive path that
    absorbs nutrients c. ulcer
  •  
  • 4. ________ also known as the colon d.
    esophagus
  •  
  • 5. ________ damaged section of stomach lining e.
    small intestine
  • (page 482)
  •  

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  • BiologyThe Study of Living Things
  • The Skeletal and Muscular Systems
  • The human body depends on the skeletal and
    muscular systems for motion and protection. The
    human skeleton contains 206 bones, made mostly of
    the minerals calcium and phosphorus. The inner
    section of a bone has soft tissue called marrow,
    where blood cells are created. Bones are
    connected at places called joints. Some joints,
    such as the plates of the skull, are fixed. Some,
    such as the vertebrae, are slightly movable, and
    some are quite movable such as the elbow or the
    shoulder. Ligaments are attached to bones and
    help hold them together. (page 482)

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  • The Skeletal and Muscular Systems
  • (page 482)

145
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  • BiologyThe Study of Living Things
  • The Skeletal and Muscular Systems
  • (page 482)
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