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Today

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Today s Agenda Journal Question : What is a chromosome? *1. Lecture: Introduction to Chromosomes, Mitosis & Meiosis ( 47) 2. Packet for Unit (Bring to class ... – PowerPoint PPT presentation

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Title: Today


1
  • Todays Agenda
  • Journal Question What is a chromosome?
  • 1. Lecture Introduction to Chromosomes,
    Mitosis Meiosis (slide 47)
  • 2. Packet for Unit (Bring to class every
    period)
  • (Buy Color Pencils Glue Stick)
  • 3. Todays Focus DNA Characteristics
    Chromosome Structure
  • 4. Color first picture in packet DNA The
    Double Helix.
  • 5. Video Genetics

2
Cellular Division/Reproduction
  • Dr. Rick Woodward

3
DNA Characteristics
A. Long thin molecule (double helix) that stores
genetic information (Unit of Heredity) Blueprint
for Life B. Location Nucleus of the Cell
4
DNA Characteristics
  • C. Function Controls Directs Activities of
    the Cell
  • D. In humans there are 6 billion pairs of
    nucleotides
  • - If a cell were the size of a basketball, the
    DNA would stretch for 40 miles!

5
Chromosome Structure
  • A. DNA is coiled into very compact structures
    called chromosomes.
  • B. Chromosomes are rod-shaped structures of DNA
    Protein.

6
Chromosome Structure
  • C. A histone is a protein molecule that DNA wraps
    around during chromosome formation.

7
Anatomy of a Chromosome
8
Chromosome Number
  • A. Each species has a specific number of
    chromosomes in each cell.
  • B. For each chromosome there are two copies or
    one pair (total)
  • (1) one from the mother
  • (2) one from father

9
Chromosome Number
  • C. Humans have 46 chromosomes (23 pairs)
  • D. Gorillas have 48 chromosomes (24 pairs)
  • E. Your neighbors cat has 32 chromosomes (16
    pairs)

10
Genetically Engineered Cats
  • 1. Some day these cats may rule the planet with
    the assistance of militant cows.
  • 2. What you are about see is classified top
    secret by the federal government.

11
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12
Not Genetically Modified
13
Genetically Modified Cats
  • Martial Arts Super Cats

14
Extreme Kung Fu Cat
15
Bi-Pedal Snow Cat Dodging a Bullet
16
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17
Karaoke Cats Transmitting Code
18
Gaming Nintendo Wii Cat
  • Genetically superior gaming skills

19
Laser Cats
20
Diabolical Joker Cat
21
Cat-Mountain Goat
22
More Laser Cats
23
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24
What is a Chromatid?
  • A. It is one of two identical parts of a
    chromosome

25
What is a Centromere?
  • A. Each chromosome has a central constricted
    region called a centromere that serves as an
    attachment point.

26
What is a telomere?
  • A. The telomeres protect the tips of the
    chromosomes from damage.

27
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28
Sex Chromosomes
  • A. Determines the sex of an organism.
  • B. In humans
  • XX female
  • XY male

29
Autosomes
  • A. An autosome is a chromosome that is not a sex
    chromosome.

30
Karyotype A Picture of an Individuals
Chromosomes
31
Homologous Chromosomes
  • A. Every cell of an organism produced by sexual
    reproduction has two copies of each autosome.

32
Homologous Chromosomes
  • B. We get one copy of each autosome from each
    parent.
  • C. Two copies of each chromosome are called
    homologous pairs of chromosomes.

33
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34
Haploid (1n) vs. Diploid (2n) Cells
  • A. Haploid Cells (1n)
  • (1) One set of chromosomes
  • (2) Sperm cells
  • (3) Egg cells
  • B. Diploid Cells (2n)
  • (1) Two sets of chromosomes
  • (2) All non-reproductive cells.
  • (3) Zygote/Fertilized Egg
  • C. Red blood cells do not have any chromosomes
    because they are missing a nucleus

35
Prokaryote vs. Eukaryote
  • A. Prokaryotes lack membrane-bound organelles.
  • 1. Bacteria
  • B. Eukaryotes have membrane-bound organelles
    (mitochondria, nucleus, etc.)
  • 1. Plants Animals

36
Cell Division in Prokaryotes
  • BINARY FISSION is the division of a prokaryotic
    cell (bacteria) into two identical cells!
  • 1. DNA copied
  • 2. Cell begins to divide
  • 3. Two identical haploid cells.

37
CELL DIVISION IN EUKARYOTES
  • Both the cytoplasm and the nucleus divide.
  • Two types
  • 1. MITOSIS (clones)
  • A. Reproduction of unicellular organisms
  • B. Addition of cells to a tissue or organ.
  • 2. MEIOSIS (gametes/sex cells)
  • A. 1/2 the chromosome number
  • B. Cells recombine in sexual reproduction.

38
DNA Replication
The DNA must be copied and then divided exactly
so that each cell gets an identical copy.
39
Cellular Reproduction (Mitosis)
  • A. Growth is the result of a cells ability to
    reproduce itself.

40
Cellular Reproduction (Mitosis)
  • (1) New body cells are produced from other,
    already existing cells when one cell becomes
    two.
  • (Recall The Cell Theory)

41
Cellular Reproduction (Mitosis)
  • (2) Examples Skin cells, intestinal tracts
    cells are continuously being replaced.

42
Cellular Reproduction (Mitosis)
  • B. New cells are produced that contain the same
    genetic information as the cells from which they
    came.

43
Cellular Reproduction
  • C. Mitosis The process that produces and
    replaces body cells exact copies.
  • (i.e. skin cells)
  • 1. Continuance of an individuals growth
    throughout life.

44
Cellular Reproduction
  • D. Meiosis The process that produces
    reproductive cells needed for the formation of
    new individuals.
  • 1. Continuance of the species.

45
Cellular Reproduction
  • I. Life from Life Cells from Cells
  • A. Disproving Spontaneous Generation
  • (1668, Francesco Redis controlled experiment
    showed that maggots do not spontaneously generate
    from decaying meat.)

46
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47
Cellular Reproduction
  • B. Louis Pasteur disproved the theory that
    microorganisms are not spontaneously generated
    from air.
  • 1. Used a flask with a long S-shaped neck,
    boiled broth.
  • 2. Pasteurization is the partial sterilization
    of a substance by increasing the temperature of
    that substance to destroy objectionable organisms
    (i.e. bacteria).

48
Cellular Reproduction
  • C. Reproduction of Body Cells (Mitosis)
  • 1. Cell reproduction occurs when parent cells
    divide.
  • A. Two new daughter cells arise from each
    parent cell.

49
Cellular Reproduction
  • B. After reaching full development, an organism
    needs new cells to
  • (1) repair damaged tissue, replace cells that
    are lost from outer surfaces (skin cells) and
    resist disease.

50
Cellular Reproduction
  • C. It is estimated that 25 million cell
    divisions occur every second in the adult human
    body.

51
Cellular Reproduction
  • D. Rapid cell division or cell growth that is out
    of control is called cancer.
  • 1. Suffix -oma

52
Looking at Cancer Cells
53
  • Todays Agenda
  • Journal Questions
  • a. What is the difference between mitosis and
    meiosis?
  • 1. Lecture Cellular Reproduction The Stages
    of Mitosis (Slide ..)
  • 2. Film on Cell Division
  • 3. Homework Work on packet and study
  • 4. Lab next class Karyotype Activity
    Microscope lab Identifying the stages of cell
    division.
  • 5. Study Guide given out next week. (Exam will
    also cover the organelles of the cell)

54
The Cell Cycle
55
Cellular Reproduction
  • 2. The Cell Cycle
  • (Interphase Mitosis The Cell Cycle)
  • Interphase
  • (1) Interphase (non-reproducing stage that
    follows when cell reproduction/replication is
    complete)

56
Cellular Reproduction
  • (2) DNA Synthesis Duplication occur during
    Interphase.

57
Cellular Reproduction
  • 2. The Cell Cycle continued
  • A. The cell spends most of its life in
    interphase.
  • B. Chromatin is present in the nucleus during
    interphase.
  • C. Midway through interphase each chromosome and
    the DNA it contains replicates.

58
Mitosis
  • Mitosis Division of nuclear material
  • a. There are four stages
  • b. Mitosis occurs in most of the cells in
    Eukaryotes.
  • P.M.A.T.
  • Please make another taco.
  • Prophase, Metaphase, Anaphase, Telophase

59
Vocabulary
  • -Centromere region where two chromatids join
  • -Chromatid Either of two strands that together
    form a chromosome.
  • -Gamete Sex Cell (Sperm or Egg)

60
Anatomy of a Chromosome
61
Anatomy of a Chromosome
  • Review A. The telomeres protect the tips of
    the chromosomes from damage.

62
Anatomy of a Chromosome
  • Review A histone is a protein molecule that DNA
    wraps around during chromosome formation.

63
Vocabulary
  • -Cell plate forms the plasma membrane between
    two new plant cells.
  • -Spindle (shown in green) Structure located
    between the centrioles of a cell.

64
The Four Stages of Mitosis
  • (1) Prophase (first stage of mitosis)
  • A. Chromosomes condense and organize nuclear
    membranes and nucleoli disappear spindle
    apparatus assemble and attach to centromeres of
    duplicated chromosomes.
  • -Each strand is a replica of the other and is
    called a chromatid.

65
The Four Stages of Mitosis
  • (2) Metaphase (second stage of mitosis)
  • A. Spindles line up duplicated chromosomes
    along the equator (middle) of the cell, one
    spindle to each half or chromatid of the
    duplicated chromosome.

66
The Four Stages of Mitosis
  • (3) Anaphase (third stage of mitosis)
  • A. The centromere of each duplicated chromosome
    is separated and paired chromatids are pulled
    apart.

67
The Four Stages of Mitosis
  • (4) Telophase (Forth stage of mitosis)
  • A. Chromosomes uncoil nucleoli reappear,
    cytokinesis
  • (Cyto cell, Kine movement) occurs and
    genetically identical daughter cells are
    produced.
  • -(In animal cells, the plasma
  • membrane pinches in.)
  • -(In most plants, a cell plate begins to appear.)

68
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69
Cytokinesis
70
Mitosis Animation
71
Summary of Mitosis
  • Prophase
  • Chromosomes condense
  • Nuclear envelope disappears
  • centrosomes move to opposite sides of the cell
  • Spindle forms and attaches to centromeres on the
    chromosomes
  • Metaphase
  • Chromosomes lined up on equator of spindle
  • centrosomes at opposite ends of cell
  • Anaphase
  • Centromeres divide each 2-chromatid chromosome
    becomes two 1-chromatid chromosomes
  • Chromosomes pulled to opposite poles by the
    spindle
  • Telophase
  • Chromosomes de-condense
  • Nuclear envelope reappears
  • Cytokinesis the cytoplasm is divided into 2 cells

72
Mitosis Review
73
Control of the Cell Cycle
  • A. Rate of Cell Division
  • 1. Different types of cells divide at different
    rates.
  • 2. Bone marrow cells reproduce rapidly to form
    new red blood cells.
  • -Red Blood Cells are replaced every 120 days.

74
Control of the Cell Cycle
  • 3. Nerve and muscle cells never reproduce once
    they mature.

75
Control of the Cell Cycle
  • 4. If one kind of cell begins to reproduce too
    rapidly, cancer develops.
  • (a) Malignant Cancers are deadly.
  • (b) Benign Cancers are not usually deadly.

76
Regulation of the Cell Cycle
  • A. Most normal cells will divide repeatedly
    until they come in contact with another cell.

77
Regulation of the Cell Cycle
  • B. When cells stop dividing, they always stop at
    the same point in the cell cycle just before DNA
    replication begins in interphase.

78
Regulation of the Cell Cycle
  • C. Control proteins have been discovered that can
    activate mitosis.

79
Meiosis (Sexual Reproduction)
  • A. Meiosis Reduces the chromosome number by
    half and results in new genetic combinations in
    the gametes.

80
Meiosis (Sexual Reproduction)
  • B. This process of cell division is involved in
    sexual reproduction.
  • (1) Recall Mitosis is for cellular
    reproduction

81
Meiosis (Sexual Reproduction)
  • C. In animals meiosis often results in two
    gametes haploid egg (1n) cells and haploid sperm
    cells (1n).
  • (1) Sperm (n) Egg (n)
  • Zygote/Fertilized Egg (diploid/2n)
  • (2) Zygote develops into a new organism.
  • (3) Meiosis and fertilization are important
    processes because they result in genetic
    variation.

82
Meiosis (Sexual Reproduction)
  • D. In meiosis two nuclear divisions take place
    (Meiosis I, Meiosis II) instead of one as in
    mitosis.

83
Meiosis (Sexual Reproduction)
  • E. Meiosis I, like mitosis, follows a period of
    interphase.

84
Meiosis (Sexual Reproduction)
  • F. Meiosis II occurs in each cell formed during
    Meiosis I.

85
Production of Reproductive Cells
  • Chromosome Numbers Characters
  • A. Diploid Cells
  • 1. Animal Cells Chromosomes come in pairs.
  • 2. Simple Plant Cells Do not have paired
    chromosomes (i.e. moss, fungi)

86
Production of Reproductive Cells (Meiosis)
  • Chromosome Numbers Characters
  • 3. Complex Plants have paired chromosomes.
  • (i.e. carrots, cabbages, oak trees)

87
Production of Reproductive Cells (Meiosis)
  • Chromosome Numbers Characters
  • 4. Human Cells have 23 pairs of chromosomes a
    fruit fly cells contain four pairs of
    chromosomes.

88
Cell Reproduction in Prokaryotes
  • A. Cell reproduction in prokaryotes (bacteria)
    is through binary fission.
  • B. Each new cell receives a copy of the single
    chromosome.
  • C. Prokaryotes have a single chromosome (no
    protein spools)

89
Steps of Binary Fission in Bacteria
  • See Packet (p.39)
  • 1. The single chromosome is attached to the
    inside of the cell membrane.
  • 2. A duplicate chromosome is formed.
  • 3. The new chromosome attaches to the cell
    membrane.
  • 4. Growth of new cell membrane and cell wall
    material separates the two copies of the
    chromosome and elongates the cell.

90
Steps of Binary Fission in Bacteria
  • 5. More new membrane and cell wall form and push
    inward at the midpoint of the length of the cell.
  • 6. The two chromosomes become separated.
  • 7. Two separate daughter cells are produced.

91
Cellular Reproduction
  • Answers to first page of packet p.37
  • Many early scientists performed faulty
    experiments that convinced them that (1)
    nonliving things could give rise to living
    things. This idea is called (2) spontaneous
    generation.

92
Cellular Reproduction
  • In 1668, (3) Francisco Redi disproved this
    theory. However, in 1675, the world of (4)
    microorganisms was discovered, reopening the
    split between scientists over spontaneous
    generation.

93
Cellular Reproduction
  • An experiment performed by (5) Louis Pasteur in
    1864 ended the debate. At the time, (6) air was
    believed to be necessary for spontaneous
    generation. Pasteur proved that microorganisms
    are not spontaneously generated.

94
Cellular Reproduction
  • This work led to the theory of (7) biogenesis,
    which stated that all organisms are produced from
    other (8) organisms. This tied in with the (9)
    cell theory, formulated about the same time. By
    the late 19th century, scientists worked with
    these two theories that indicated that all life
    must come from (10) life.

95
Cellular Reproduction
  • 11. Early in the organisms development, the
    cells contribute to overall growth. Later, new
    cells are needed to repair damaged tissues,
    replace lost cells, and resist disease.

96
Cellular Reproduction
  • 12. What would happen to a cell if it continued
    to grow unchecked?
  • The surface area of the plasma membrane would
    not be large enough to meet the cells needs.
    The cell would stare or become poisoned.

97
Cellular Reproduction
  • 13. Replication is the process of making an exact
    copy. It provides the cell with a second set of
    chromosomes for reproduction.
  • 14. Interphase and mitosis make up the cell
    cycle.

98
Work on the Karyotype in your packet
  • 1. Cut out chromosomes.
  • 2. Arrange into homologous pairs.
  • 3. Tall to Small, Number 1-23 pairs
  • (Recall 1-22 Autosomes)
  • (23 Sex Chromosomes)
  • 4. Glue into your composition book.

99
Todays Agenda
  • Journal Question What is a karyotype?
  • 1. Study guide for Exam Answer questions
    1-42.
  • 2. Finish your karyotype.
  • 3. Finish your packet.
  • 4. Micro-slide viewer lab
  • 5. Homework Study, Complete all of your work.
  • 6. Everything is due on Exam day.

100
Pay Attention!
  • 1. Micro-slide viewer activity first!
  • a. Plant Mitosis Slide
  • b. Meiosis Slide

101
Todays Lab Questions Write down questions 1-8
in your composition book
  • 1. What is the difference between mitosis,
    meiosis, and binary fission?
  • 2. What do homologous pairs of chromosomes refer
    to?
  • 3. Label the parts of a chromosome Chromatid,
    Centromere, Gene
  • 4. How many pairs of chromosomes do humans
    have?
  • 5. What does XX ________ and XY __________
  • 6. What is a karyotype?
  • 7. What is the function of a spindle fiber?
    What is a tetrad?
  • 8. Diagram a picture of the Cell Cycle.
    Include G1, S, G2, M

102
Today s Cell Cycle Lab
  • 1. Carefully read all instructions on todays
    laboratory handout (which is in your unit
    packet).
  • 2. Diagram/Draw all phases on the cell cycle in
    your composition book.
  • 3. List two facts for each phase.
  • 4. Answer questions 1-8 from the laboratory
    handout in your composition book.
  • 5. Start studying tonight for your exam.

103
Different Stages of the Cell Cycle (Onion Root
Tip) Todays Lab
104
Todays Agenda
  • 1.Brief Lecture Reviewing Mitosis Meiosis
  • 2. Answer Study Guide Questions 1-42.
  • 3. Complete Unit Packet

105
Exchanging Genetic Information Crossing Over
106
Crossing Over
  • Exchanging genetic information and producing
    genetic variation.

107
Crossing Over
108
Gametes are genetically different from the
parent cell because.
  • 1. Independent assortment/Crossing Over
  • 2. Meiosis is important to make gametes.
  • 3. Meisosis and fertilization are important
    because the end result is genetic variation.

109
Tetrads
110
Tetrad
  • When the two homologous pairs are aligned (side
    by side) we call the pair a tetrad.

111
Mitosis
  • Somatic Cells Body Cells
  • ie. Skin Cells
  • Cells that make up your toe.mitosis.

112
Meiosis
  • Gametes Reproduction
  • A. ____ Determines the gender of the child.

113
Meiosis
  • Gametes (Sex Cells)

114
Haploid (1n) Diploid (2)
115
Work on your Study Guide!
116
Get Started.
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