Cell Specialization and Organization - DOC

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					        Cell Specialization and
                Organization


Multicellular organisms are made up of many cells.

These cells have different appearances and

perform different functions (or jobs)  they are

specialized for certain tasks.



For example:

    Muscles cells, which affect movement by

    shortening, are typically elongated and tapered

    at either end.

    Epithelial cells (those that form the lining of

    the lung) are thin and flat, because they easily

    allow substances to pass through them easily.

    Nerve cells have a cell body with an elongated

    axon or fibre that is surrounded by insulating
cells. Its form is related to its function of

carrying electrical signals long distances within

the body to communicate information.

Bone cells secrete a matrix mineral in which

they live to provide the body with a bony

support.

Red blood cells are thin and disk-like, and

extrude their nucleus which helps to maximize

their capacity for carrying oxygen.
Structure is related to function!


   Read page 138-139. Can you identify the cells on page
                         139????



BLM 2-16
  Advantages of being Multicellular   (Read page 139)


  Cells become specialized at performing one or

    two jobs. As a result the cell becomes very

    efficient at doing those jobs.

  Examples:

      o Red blood cells become efficient at

        picking up oxygen and carrying it to other

        cells

 The specialized cells all contribute to the

overall functioning of the organism

 the organism can live in a variety of

environments (land, water)

 the organism can grow to a large size

 the organism can obtain energy from a variety

of food sources
                   Cell Organization

Recall the levels of organization in living things.

(C T  O  S)

Read page 140



            Tissues (2 level of organization)
                     nd




BLM 2-18

BLM 2-19



A tissue is a group of cells having a similar set of

limited functions.

Examples:

   Muscle tissue – moves body parts

   Nerve tissue – carries signal between the brain

    and other parts of the body to co-ordinate

    activities
   Connective tissue (bone) – provides physical

    protection and support for the body.

   Epithelial tissue – is a very thin tissue that

    lines the intestine and the lungs.



Plant tissue consists of xylem tissue, phloem tissue

and epidermal tissue.



Activity on page 142 – Looking at animal tissues

Hand in #1 & 2 under “What did you find out”
    Organs (3 level of organization)
               rd




- are structures that consist of at least two

  tissues.

- Each organ performs a specific function for

  the body that no other organ can perform

- Examples:

    o Heart – pumps blood throughout the body

    o Kidneys – filters the blood

    o Lungs – oxygen and breathing



  - Plant organs include the root, stem, and

  leaves.
Draw figure 2.24 into notes!

You may use different colours!



  In your lab groups work on the investigation on

                    page 143.
Plants have 2 main systems:

  1) the root system

      a. below the ground

      b. function is to obtain water and minerals

        from the soil and to anchor the plant to

        the ground

  2)the shoot system

      a. above the ground

      b. function is to make food for the plant
BLM 2-17



Page 144 #1-5

Pager 145 #1-5, 7, 8, 11, 13, 14

				
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