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Cell structure and function ClickBiology

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Cell structure and function ClickBiology Powered By Docstoc
					ClickBiology
Cambridge IGCSE Biology
    Extended Level

         Cells



                          ClickBiology
             You should be able to:
• Identify and describe the structure of plant cells and animal cells,
  and describe the functions of their parts.

• Describe the difference between animal cells and plant cells.

• Explain the structure and function of specialised cells: red blood cell,
  muscle cells, ciliated cells, xylem vessels and root hair cells.

• Define the terms tissue, organ and organ systems, with examples.




                                                                   ClickBiology
A section through a liver cell (animal
                cell):

cell membrane                 nucleus
controls what                 contains the
enters and                    DNA and so
leaves the cell               controls the cell


   cytoplasm                  DNA
   metabolic                  contains the
   (chemical)                 coded
   reactions                  instructions to
   occur here                 make proteins




                                         ClickBiology
Section through a palisade cell of a leaf
              (plant cell)


                              chloroplast
cell membrane



                              large sap vacuole
      nucleus



                              cellulose cell wall
     cytoplasm




                                            ClickBiology
             You should be able to:
• Identify and describe the structure of plant cells and animal cells,
  and describe the functions of their parts.

• Describe the difference between animal cells and plant cells.

• Explain the structure and function of specialised cells: red blood cell,
  muscle cells, ciliated cells, xylem vessels and root hair cells.

• Define the terms tissue, organ and organ systems, with examples.




                                                                   ClickBiology
Comparing animal and plant cells

Found in both animal   Found only in plant
   and plant cells           cells

  cell membrane        cellulose cell wall

     nucleus           large sap vacuole

    cytoplasm             chloroplast



                                             ClickBiology
             You should be able to:
• Identify and describe the structure of plant cells and animal cells,
  and describe the functions of their parts.

• Describe the difference between animal cells and plant cells.

• Explain the structure and function of specialised cells: red blood cell,
  muscle cells, ciliated cells, xylem vessels and root hair cells.

• Define the terms tissue, organ and organ systems, with examples.




                                                                   ClickBiology
       Red blood cells transport oxygen

       cell surface membrane        cytoplasm contains
                                    no nucleus
                                           allows more room for
                                           haemoglobin

cytoplasm contains
haemoglobin
haemoglobin is a
protein which carries          bi-concave disc shape
the oxygen molecules           increases surface area
                               over which absorption of
                               oxygen can occur



                                                                  ClickBiology
     Muscle cells contract and enable
         movement of the body

                              muscle


                                              Muscle cells have
                                              many nuclei


                                  cell surface membrane
                                                          nucleus
The strands of protein
slide over each other
making the muscle cell
(fibre) shorter and causing
the muscle to contract
                                   protein strands


                                                          ClickBiology
Ciliated cells move bacteria and dust
         away from the lungs
        cilia


                     Cilia are small extensions of
                     the cell. They beat rhythmically
                     to sweep mucus, which has
                     trapped bacteria and dust,
                     away from the lungs


                           nucleus



                             magnification X3000


                                                 ClickBiology
    Xylem vessels transport water and
          minerals up the plant
                                       xylem vessels are continuous tubes

  xylem vessel




no cytoplasm
hollow: allows for
continuous flow of
water and dissolved
mineral ions

    lignin
    water-proof and strong;
    helps support the plant
                              cross-section           longitudinal section

                                                                    ClickBiology
   Root hair cells absorb minerals and
           water from the soil
  Cross-section of a root hair cell


                                      cell membrane semi-permeable, so will
                                                    allow water and mineral
cytoplasm                                           ions into the cell
contains no
chloroplasts as no
photosynthesis is
needed
                                                 root hair
                                       increases surface area for absorption
                                       of water and mineral ions




                                                                       ClickBiology
             You should be able to:
• Identify and describe the structure of plant cells and animal cells,
  and describe the functions of their parts.

• Describe the difference between animal cells and plant cells.

• Explain the structure and function of specialised cells: red blood cell,
  muscle cells, ciliated cells, xylem vessels and root hair cells.

• Define the terms tissue, organ and organ systems, with examples.




                                                                   ClickBiology
  A tissue is a group of cells of similar
structure that perform a shared function
           Tissues found in the leaf                Animal tissues:
                                                    muscle tissue
                                upper epidermal
                                tissue
                               palisade mesophyll
                               tissue


                                spongy mesophyll    nervous tissue
                                tissue
                                lower epidermal
                                tissue


 Cross-section of a leaf

                                                             ClickBiology
 An organ is a structure made of a
group of tissues working together to
     perform specific functions
        heart       lungs      liver




        stomach     brain     kidneys


Plant organs include the stem and the leaves
                                        ClickBiology
 An organ system is a group of organs that
  coordinate to perform related functions
lymphatic       digestive          reproductive         skeletal        endocrine
  system         system               system            system           system




        respiratory         excretory             muscular         nervous      circulatory
          system             system                system          system         system


In plants the shoot is an organ system consisting of leaves and the stem
                                                                              ClickBiology
        Levels of organisation
 cell         tissue    organ     organ        organism
                                 systems




nerve cell    nervous    brain    nervous   Homo sapiens
               tissue             system

   smallest                                 largest

                                                      ClickBiology
       Now you should be able to:
• Identify and describe the structure of plant cells and
  animal cells, and describe the functions of their parts.

• Describe the difference between animal cells and plant
  cells.

• Explain the structure and function of specialised cells:
  red blood cell, muscle cells, ciliated cells, xylem vessels
  and root hair cells.

• Define the terms tissue, organ and organ systems, with
  examples.



                                                        ClickBiology
     Now write down everything you
    remember from the presentation
• Don’t refer to your text book straight away,
  see what information you have retained.
• Check the notes you have made by
  checking your book.




                                          ClickBiology
Edexcel AS Level Biology



ClickBiology
                    Next video:
         Transport into and out of the cell
    (diffusion, osmosis and active transport)



                                                ClickBiology

				
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