Learning Objectives:
After completing this practice, the student should be able to:

• List different phases of interphase.
• Describe importance of each phase of interphase.
• Discuss major biochemical events in each phase of interphase.

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The eukaryotic cell cycle allows the cell to grow and divide. In mitosis one parent cell produces two daughter cells with the same kind and amount of information (chromosomes)  as the parent cells. The mitotic cell cycle is composed of the interphase and the M phase. A cell undertakes interphase prior to the M phase. The interphase is further subdivided into gap1 (G1), synthesis (S), and gap2 (G2) phases. In interphase (G1, S, G2), DNA (chromosomes) replication and most of the cell's growth and chemical activity take place. The M phase  is composed of the mitotic phases (prophase, metaphase, anaphase, and telophase) which divides the nucleus of the cell and cytokinesis which divides the cytoplasm. As a result of one mitotic division, one parent cell produces two daughter cells genetically identical.

• Use the Textbook to characterize each step of the Interphase.
• Write down the purpose of the Interphase.
• Simulate all phases of the interphase:
• draw the contour of a cell on a piece of paper showing the plasma membrane,  cytoplasm, and nucleus. Build two pairs of homologous chromosomes (each chromosome with one chromatid) by using colored pipe cleaners or thick strings and place it at the center of the nucleus. Although chromosomes are not visible during the Interphase (they appear as chromatin), but try to visualize the chromosomes.
• Simulate  G1 of the interferes on the paper:
• proteins are synthesized, organelles are divided in two , and the cell grows (look at the appropriate figures in the text and play video clips on Educator's appropriate packet).
• Duplicate the two pairs of chromosomes (each chromosome is double stranded (sister chromatid), and simulate S phase of the interphase.
• Simulate the G2 phase.
• Visit the following sites to learn more about the Interphase. Pay attention to the relationships between the structure and function of the cellular components- such as the chromatin, cell membrane, nuclear membrane, and the size of the cell.
• Cell Division
• Cell Cycle
• Cell Cycle and Mitosis
  
• Onion Root Tip

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1. Prepare a simulation report composing of the following:

• Draw a diagram of a cell cycle and show (by labeling) G1,S, and G2 events of the interphase.
• Outline  the major events of G1, S, and G2  during the interphase.
• Answer the following questions:
• Your nerve and muscle cells do not divide anymore, which phase of the cell cycle is terminal for these cells? Why?
• Explain why simulation and depicting are important for studying biological systems.

2. Do an online search:

• Use your Internet browser and then open to a search engine (google or yahoo, etc.)
•  Type "plant genome"  or " plant genetics" in the query box and submit the query (click on the search box).
•   Many files appear.
•   Read summary of a few files and then choose and click on a genome file.
•   Read the file.
•   Make a brief description of the file (one page) and include the  URL, author and  institution.
•   Write your own reflection to the article (one paragraph).

The following assessment device (PTA) will provide a scale to measure student's performance. It will be used to grade your assignment.