Unit 1 The Power of Reproduction

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Unit 1 The Power of Reproduction Powered By Docstoc
					   Unit 1
The Power of
Chapter 1 – The Cell Cycle and
   Asexual Reproduction
       Amazing Cells
Animal Cell

              Plant Cell
          1.1 The Cell (Pages 4 – 16)
1.    Scientists have long been fascinated with
      life. After thousands of years of studying
      it we still haven’t figured out how it
      works. Some history:
2.    Assignment:
     a)   The Cell Question Sheet
     b)   Label Cell Diagrams (1-6 & 1-7)
     c)   Cell Structures Chart
             Chapter 1.1 – The Cell Question

1.    Record the date and contribution to cell
      theory for the following scientists: (22)
     a)   Aristotle (384-322 BC) – animal and plant
          kingdom (animals higher, spontaneous
     b)   Zacharias Janssen (1590) – first
          compound microscope
     c)   Robert Hooke (1665) – microscope –
          referred to cells as “rooms”
     Chapter 1.1 – The Cell Question
1.    Record the date and contribution to cell
      theory for the following scientists: (22)
     a)   John Ray (1667) – “species” organism
          that reproduce with their own kind
     b)   Francesco Redi (1668) – disproved
          spontaneous generation (flies and
The Redi experiment
Replica of a Leeuwenhoek microscope
The following photomicrographs were taken
through a Leeuwenhoek microscope.
a)   Anton van Leeuwenhoek (1632 – 1723) -

b)   Robert Brown - nucleus is part of the cell

c)   Schleiden/Schwann (1838/1839) – all
     organisms are made of cells

d)   Alexander Carl Heinrich Braun (1845) –
     the cell is the basic unit of life
e)   Charles Darwin and Alfred Wallace –
     species form variations
f)   Rudolph Virchow (1821 – 1902) – cells
     come from cells

g)   Louis Pasteur (1860) – disproved
     spontaneous generation at the
     microscopic level (life comes from life)
swan neck
1.    Like all sciences, biology has its own
           set of tools, techniques, and
        investigative methods. What tools
         helped scientists develop the cell
                    theory? (3)

     2.   What methods helped scientists
           develop the cell theory? (2)
2.   What methods helped scientists
      develop the cell theory? (2)

1. State a question
2. Form a hypothesis (educated guess –
   what you think will happen)
3. Design an experiment
4. Make observations
5. Draw conclusions – answer hypothesis
4.   The internet was originally designed to
       allow scientists all over the world to
      communicate quickly and easily with
        each other. What invention had a
            similar effect on scientific
      communication in earlier centuries?
5.    What can you conclude about the
       relationships between scientific
     discovery, tool inventions, and new
                methods? (1)
     6.   Cell theory states that: (4)
•   all living organisms are made up of one
    or more cells
•   Cells are the basic unit of life
•   Cells come from cells
•   Activity of entire organism depends on
    total activity of its independent cells
Animal Cell
Plant Cell
   BLM 1-5, 1-8, 1-9, 1-10, Investigation 1-
           Cell Structures Chart
  Cell Size and Scale
1. Nucleus
       contains the cell’s genetic material
       holds instructions for making/building the
2. Nuclear Membrane
       encloses the cells’ genetic material
       contains the DNA
         Cell Structures Chart
3. DNA
   Deoxyribonucleic Acid
4. Chromatin
   Long strands of DNA
5. Nucleolus
   dark area within the nucleus
   manufactures ribosome parts
       Cell Structures Chart
6. Ribosomes
  contribute to the manufacture of proteins
7. Cell Membrane
  separates the contents of the cell from its
  selectively permeable membrane that allows
   only certain material in and out of the cell
        Cell Structures Chart
8. Cytoplasm
  jelly-like material
  supports the nucleus and other organelles
9. Endoplasmic Reticulum
  a folded membrane that forms a series of
  transports materials to different parts of the
   cell (like our circulatory system)
         Cell Structures Chart
10. Mitochondria
   transform energy for the cell (sugar to ATP)
   cellular respiration takes place here (this is
    not in your text, please copy it)
11. Golgi Bodies
   package useful materials
   then it secretes them to the outside of the cell
    (like our digestive system)
        Cell Structures Chart
12. Vacuoles
   fluid filled store houses for water, waste and
    nutrients (like our digestive system)
13. Lysosomes
   break down food and digest wastes and
    worn out cell parts (like our digestive
        Cell Structures Chart
             Plants Only
14. Cell Wall
   Provides structure and support for the cell
    (acts like the cells’ skeleton)
15. Chloroplasts
   this is where photosynthesis takes place
   photo means “involving light” and “synthesis
    means “to make”
                            BLM 1-5
Life Function             Body System           Cell Part(s)

Taking in nutrients and   Digestive System      Mitochondria
using energy

Eliminate wastes          Excretory System      Vacuole and lysosome

Control center            Nervous System        Nucleus

Building and repairing    Circulation and       ER, ribosomes and
body parts,               Digestion systems     golgi bodies
transporting nutrients

Contains genetic          Reproductive system   Nucleus
1.2 Understanding the Cell Cycle
   Cells grow and then divide to make new
   New cells are used to replace dead ones
    OR for growth of the organism.
     YOU started out as 1 cell!
     Before a cell can divide into 2 cells it must

      produce almost twice as many organelles
     A cell’s stages of life are called phases.
               1. Interphase
   Most of cell’s life
   DNA in thin strands called Chromatin
   Chromatin coils up to form double
    stranded Chromosomes.
   A Centromere connects the original
    chromatin with its identical replicate.
   The cell has a complete extra copy of
A Chromosome
2. Prophase
 Duplicate DNA is easily seen under
 Nucleolus and Nuclear Membrane
 Centrioles move to opposite sides of
    the cell. (Fishing boats)
 Spindle fibres (like a scaffold) grow out
    of each centriole and attach to
    centromere. (Fishing line)
3. Metaphase
 Spindle fibres pull on centromeres
 Chromosomes move to line up in the

4. Anaphase
 Spindle fibres shorten and pull
    centromere apart.
 One copy of DNA goes to each side.
5. Telophase

   A complete set of chromosomes
    arrives at each centriole.
   Spindle fibres disappear.
   Nuclear membrane and nucleolus
   Chromosomes uncoil into thin
5. Telophase (cont’d)

   Cell membrane pinches together in the
    middle (cytokinesis)
   Two cells form (animal cells).
   A cell plate grows across the middle of
    the cell forming a new cell wall
    between the two cells. (plants)
Parent Cell   Daughter Cells
Phase 1:
 Phase 2:
Phase 3:
 Phase 4:
           Mitosis Animation Clips
 organelles and mitosis
 In depth mitosis
 BLM’s 1-14, 1-15, 1-16 & 1-17
 Mitosis Crossword & Mitosis Chart
 Mitosis Quiz
1.3 The Cell Cycle in YOUR Body
 Some common chromosome counts:

 Dogs                 78
 Tomatoes             24
 Humans               46
 Black Molly (fish)   46
Cell need to divide for the following
 1.        Normal Cell Replacement
      a)    Cells die of old age and need to be
            replaced. See pg 25 for cell life spans.
              •   About 3 billion cells die in your body every
      b)    Cells die due to damage or when they
            don’t get enough food or oxygen.
      c)    Regeneration - Healing of damaged
            tissue or the replacement of body parts is
            called regeneration. (NOTE: see note
            under Figure 1.17 – pg 26)
2.     Growth
     a) As organisms grow larger, their cells
        stay the same size
     b) They just get more of them.
1.   Aging is connected to the slowing of the
     cell cycle.
2.   The cells do not divide as often or as
1. Caused when the DNA of a cell becomes
damaged by:
a) Tobacco
b) Asbestos
c) Certain chemicals
d) some viruses
e) Radioactivity
f) UV radiation
2.       The damage injures but does not kill the cell.
3.       The cell no longer functions properly and the
         DNA no longer has correct information about
         when and how quickly to divide.
4.       The result: Useless cells divide often and
         quickly forming a lump.
5.       If the cancer cells can easily be transported the
         cancer can spread all over.
6.       The lump crowds out good cells and use up a
         lot of food and oxygen.
     •    Worksheet & Cancer Research
1.    Explain a process in the human body
      in which there is evidence of the cell
      cycle at work. (1)
    Growth and development
2.       Give two reasons why cells die. (2)

        Damaged
        Programmed to live a certain amount of
         time – no longer needed
        Lack of food or oxygen
        Failed mitosis
3.     How do scientists currently explain
       the aging process? (2)
    The cell cycle is slowing down
4.     Describe what happens when cells
       divide uncontrollably. (2)
    Cancer – these cells are like weeds in a
     garden, choking out the healthy
    5.   Using your knowledge about
         cancer and cell division, explain
         how you think sunscreen can help
         reduce the risk of skin cancer. (2)

   It blocks the UV rays and prevents them
    from damaging the genetic material
6. Some cells live for years, while
   others live for only a few days.
    Why do you think some cells
    might be replaced faster than
             others? (2)
   Some cells are damaged more quickly
    by their environments (stomach acid).
7.       The muscle cells of the heart were once
         thought to stop dividing when a person
         reached the age of nine. Thus, heart attacks,
         which kill heart cells, were believed to cause
         permanent damage to the heart muscle. New
         research has discovered that mitosis does
         occur in the heart later in life. What do you
         think this new discovery means for people
         who have heart attacks? (2)

        Your body is capable of regenerating
         heart cells – this gives heart attack
         survivors hope for recovery
 1.     What are four primary habits that
        everyone should adopt to lower their
        overall cancer risk?

 Eat Healthy
 Be Active
 Get Screened
 Don’t smoke
               Eat Healthy
 1/3 of cancer deaths are linked to diet
 Reduce dietary fat, especially animal fat
 Start small – add a few servings of fruits or
 Limit alcohol consumption (men-2,
 Eat less red meat & cut out processed
                 Be Active
 Make  physical activity part of daily routine
 Make it part of your social life
 Schedule activity for your “energy’ times
 Stay motivated – checklist or friend
 Learn new skills – club, group etc.
1. What happens to our cells to
   bring about cancer? (2)
   Cancer is a disease that starts in our cells.
    Our bodies are made up of millions of
    cells, grouped together to form organs or
    tissues such as the lungs, the liver,
    muscles and bones.
   Genes inside each cell order it to grow,
    work, reproduce and die.
2. What is a tumor/lump made
   up of? (2)
   Normally these orders are clear, our cells
    obey and we remain healthy. Sometimes a
    cell’s instructions get mixed up and
    it behaves abnormally. After a while
    groups of abnormal cells form lumps or
      3. What is the difference
         between a benign and
         malignant tumour? (2)
   Tumours can be either benign (non-
    cancerous) or malignant (cancerous).
   Benign tumour cells stay in one place in
    the body and are not usually life-
Malignant tumour cells are able to
 invade the tissues around them and
 spread to other parts of the body.

 Cancerous cells that spread to other
 parts of the body are called metastases.
The first sign that a malignant tumour
 has spread is often swelling of nearby
 lymph nodes, but cancer can
 metastasize to almost any part of the

Malignant tumours can be dangerous.

It is important to find them and treat
 them quickly, before they spread.
    4. How are cancers named? (2)
   Cancers are named after the part of the
    body where they start.
       For example, cancer that starts in the colon
        but spreads to the liver is called colon cancer
        with liver metastases.
   1.4 Asexual Reproduction
 - Bacteria, Protists, Fungi, and
    Some Animals (text p 29-35)

 Asexual Reproduction – the formation of
 a new individual that has identical genetic
 information to its parent.

                  Asexual                                             Sexual

 Binary Fission               Budding                 Conjugation              Separate Sexes

Spore Formation             Fragmentation            Hermaphroditic

      Bacteria – see p 29-30
1. Have no nuclear
2. Have only one

3. Reproduction
   asexually by the
   process of binary

              Binary Fission
4. Steps (see p 30)
a) cell wall ruptures
b) single chromosome
   gets copied
c) cell grows longer
   and a chromosome
   moves to each end.
d) cell membrane
   pinches off.
e) cell wall grows to
   surround both cells.
1. Ex) paramecium,
   amoeba, euglena,
2. unicellular organisms
   with a true nucleus

3. mitosis takes place
   creating two identical
1. Ex) Moulds, yeast,
   and mushrooms                       

2. filaments called hyphae                                                                 

   grow over the surface of

  3. Have 3 methods of asexual
  a) Fragmentation
                           Athletes Foot Fungi
– a small piece of
hyphae breaks away
and grows into a new
individual. It is
identical to its parent.
(fungi – p 32)

    b) Budding
- a copy of the
nucleus is made.
- The nuclei press
against the cell
membrane, forming                 

a bud which grows
and breaks off.
(hydra & yeast)

c) Spores
– special cells called spores are stored in
a case called a sporangium. The spores
are released when ready and go through
mitotic cell division if they land in suitable
conditions. (bread mold – p 33)


1.   Invertebrates (without backbone) make
     up 97% of animal species
2.   Ex) Planaria (Flatworms) – divide in two
     and replace the parts that are missing.
3.   Ex) Sponges and hydras – reproduce by
     budding. see pg 35.
•    READ p 29-34 and do questions 1 – 6 on
     p 19 in notes pack.
     1.5 Asexual Reproduction in

1.   Plants have an amazing ability to repair
     themselves using mitosis.
2.   They are often even able to regrow from
     a stump.
3.   Recall: asexual means DNA is exactly
     the same as its parent.
1. Animals stop growing at an adult size
2. Plants grow until they die.
3. Meristem – unspecialized cells in the
   stem and root tips which undergo
   mitosis very often.
4. Meristem cells divide and promote
   growth at the stem and root tips.
         Meristem (cont’d)
5. At some point some meristem cells
   specialize to do only a small range of
   functions. These cells no longer

6. Meristem are active at stems and root
   tips, but can become active in other
   parts of the plant IF repairs to the plant
   are needed.
          Methods of
  Plant Asexual Reproduction
     The process of making identical offspring
      to the parent using a single cell or a small
      amount of tissue from the parent.
     Humans use “cuttings” or pieces of a
      plant stem to place into soil and produce
      many offspring identical to the parent.
    1. New Plants from Roots
   These plants can grow from just root
    cuttings – pg 38
   Growers can sell just the roots.
   Eg. Dandelions, asparagus
         2. New Plants from Stems
       These plants grow from just the tips of
        the runners – p 39 & BLM 1-29
         E.g. strawberries (runners)
       Layering – A branch of the parent plant is
        bent and covered with soil – BLM 1-30
                3. Grafting
   One part of a plant is cut and connected
    to a similar plant.
   The result is a plant that is part one type
    and part another.
   This method is used for apples, grapes
    and roses.
         4. Tissue Cultures
   take a few unspecialized cells from a
   place the cells in a special growing
    solution perfect for growth.
   the laboratory produces many identical
    plants (1 from each sample)
    Text p 40
    4. Tissue Cultures (cont’d)
   useful for Chrysanthemums, orchids
    and pine trees.
   (Note – specialized cells have been
    altered to be able to carry out a few
    specialties very well but cannot carry
    out other functions.)
See BLM 1-26, 28, 29,30, 31
 and Do BLM 1-32 & 1-33

YouTube - Grafting Apple Trees

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