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)

83
Life Science - Biology

• 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)

84
Life Science - Biology

• 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)

85
Life Science - Biology

• 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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• 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
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• 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
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• 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
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• 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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• 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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• 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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• 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)

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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)

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

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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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• 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)

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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)
•  

123
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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)

124
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• 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
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• 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.

127
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• BiologyThe Study of Living Things
• The Circulatory System
• (page 478)

128
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• BiologyThe Study of Living Things
• The Circulatory System
• (page 478)

129
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• BiologyThe Study of Living Things
• Respiratory System
•  
• (page 479)

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

131
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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)
•  

132
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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
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• 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
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• 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
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• 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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• 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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• BiologyThe Study of Living Things
• The Digestive and Excretory Systems
• (page 481)

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

140
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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)

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• 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
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• 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)
•  

143
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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)

144
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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)