GAMETE CELL CYCLE NOTES How is the cell cycle by steepslope9876


									                                     GAMETE CELL CYCLE NOTES

How is the cell cycle different for GAMETES?

         Gametes are ____________ _______________________
           o Male- sperm
           o Female – egg

         Gametes are produced for ________________________ reproduction.

         Gametes are ____________________________.
           o They contain half the number of chromosomes as found in body cells (somatic cells)

            o When two __________________ cells combine, a ______________ __________________
                 is formed.

            o The zygote gets _______________ of its chromosomes from each of the parents.

  I.        Phases of the cell cycle
               (All pictures are from website:

                   INTERPHASE                                       WHAT HAPPENS?
                                                   Gametes in interphase are the same as body cells in

                                                   When the cell is large enough to divide:

                                                           Genetic material still appears as


   II.       What is meiosis?

          ___________________________ part of the gamete cell cycle
          Cells go through phases similar to mitosis

   III.      What are the products of MEIOSIS?

          Produces________ ________________ cells (contain ___________ the number of normal
                PROPHASE I                             WHAT HAPPENS?
Tetrad of chromosome #1

                                        ________________________ move to opposite
                                        sides of cell.

                                        Homologous pairs of _________ _____________

                             #2         join to create a ________________.



                                         __________________ _________ can

               METAPHASE I                             WHAT HAPPENS?
           fibers                       _____________ line up in the middle of the cell.


                ANAPHASE I                             WHAT HAPPENS?

                                        Also called ______________________.

                                        __________________ are pulled

                                        apart as spindle fibers are pulled back.

                                        Centromeres do not tear apart, so sister
                                        chromatids stay attached.

                                        _______________________________ can occur.
       TELOPHASE I                WHAT HAPPENS?
Cell pinches
                     Cell splits in two (________________________)

                     Each cell contains pairs of _______________


       PROPHASE II                WHAT HAPPENS?

                     __________________ _____________, move to
                     opposite sides of the cell

                     Sister ___________________ _____________ to
                     spindle fibers.

      METAPHASE II                WHAT HAPPENS?

                     Sister __________________ line up in the

                                          of the cell.

       ANAPHASE II                WHAT HAPPENS?

                     Spindle fibers tear the _____________________.

                     Sister ___________________ are pulled

                                         to opposite sides of the cell.
            TELOPHASE II                                     WHAT HAPPENS?

                                                A total of _______ ______________

                                                ________________ cells are produced.

                                                     Haploid =



IV.   What are differences between mitosis and meiosis?

               MITOSIS                                           MEIOSIS
Answer these questions on the back of this paper or on a separate sheet.

   1. IN YOUR OWN WORDS, define these terms:
         a. centromere
         b. crossing-over
         c. cytokinesis
         d. homologous
         e. non-disjunction
         f. tetrad

   2. The pairs of words below are easily confused. IN YOUR OWN WORDS explain the difference
      between these terms:
         a. diploid & haploid
         b. centrioles & centromeres
         c. chromosome & sister chromatids
         d. gamete cells & somatic cells

   3. Why are the end products of meiosis so important to the process of fertilization? Explain more
      than just the fact that they make eggs and sperm.

   4. Compare and contrast mitosis and meiosis. Be sure to include the end products and the steps of
      each process. You may use a Venn diagram if that helps.

   5. IN YOUR OWN WORDS, review what happens in each step of meiosis. Create a chart to help you
      organize your information.

   6. Siblings are different, even though they have the same parents. How does such variety occur?
      List the step of meiosis where this variation is created. Explain what happens in this step and
      why it allows for such variety.

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