Cell Cycle and Cell Divisions Study Guide

Unit 3: Cell Cycle Lesson 3.1 Cell Cycle and Cell Divisions Introduction You already know that your body is made up of cells. As a multicellular organism, these cells make up tissues, which will consequently make up organs and organ systems. Organisms, like plants and animals, rely on this complex organization for the proper functioning of their bodies. However, any sexually reproducing multicellular organism begins as a single-celled entity. This cell then relies on cellular events to produce more cells, the early stage of which is shown in the blastula above. Further growth and development proceed through the continuous reproduction and specialization of cells. The process repeats for as long as needed to ensure the maintenance and survival of an individual. Although not a perpetual process, organisms may still rely on the production of new cells on some occasions. Have you ever wondered how our bodies replenish cells? 3.1. Cell Cycle and Cell Divisions 1 Unit 3: Cell Cycle Learning Objectives In this lesson, you should be able to do the following: ● Identify and describe the phases of the cell cycle. ● Explain the significance of the cell cycle control points. Warm Up Pass the Ball 15 minutes The cell cycle has multiple steps. All of these steps are necessary to allow the resulting cells after division to function adequately because of the number of organelles and genetic that they will receive. Materials ● clay (one color) ● scissors ● yarn ● beads (three colors, 10 pieces each) Procedure 1. Form a group with four members. Assign each member to one of the following stages of the cell cycle. a. G1 phase b. S phase c. G2 phase d. M phase 2. To prepare for the activity, mold a piece of clay into a flattened circle of around 5 3.1. Cell Cycle and Cell Divisions 2 Unit 3: Cell Cycle inches in diameter. This represents the cell. Add the following to the clay circle. a. Obtain a piece of yarn around 3 inches long and add it to the circle. This represents DNA or the genetic material of the cell. b. Add three pieces of every bead color to the circle. This represents nutrients and other molecules present inside the cell. 3. Begin the activity by following the steps below. a. Give the cell model to the student assigned to the G1 phase. i. The assigned student must add clay to make the model larger. ii. Let that same student add beads to the cell model. b. Pass the model to the student assigned to the S phase. i. Let that student add an identical piece of yarn to the model. c. Pass the model to the student assigned to the G2 phase. i. The assigned student must add clay to make the model larger. ii. Let that same student add more beads to the cell model. d. Pass the model to the student assigned to the M phase. i. Let the assigned student split the model into two separate portions, with each receiving an equal quantity of yarn and beads. ii. Make sure that the two new models are roughly the same size as the one before the clay was added during the G1 phase. 4. For every step, observe and take note of what happens to the model. Complete Table 3.1.1. Also, write down what you think happens to the cell based on the changes in the model. 5. Answer the guide questions that follow. Data Table Table 3.1.1. Observations on the stages of the cell cycle Phase Observations in the Model What Happens to the Cell G1 S G2 M 3.1. Cell Cycle and Cell Divisions 3