Lesson Plan

Life Stages: Mitosis

Objectives

In this lesson, students will learn about the phases of mitosis by predicting the order of the phases and by drawing diagrams of the chromosomes during the various phases. Students will:

  • make connections between cell division and the growth of organisms.
  • predict the order of the phases of mitosis given diagrams in a scrambled order.
  • diagram the various stages of mitosis showing the movement of chromosomes in the cell.
  • create mnemonic devices to help students remember the order of the phases.

Essential Questions

Vocabulary

  • Mitosis: The process by which a cell separates the two copies of its DNA into two daughter cells.
  • Interphase: The phase of the cell cycle in which chromosomes are not visible (unwound as chromatin, not condensed as chromosomes).
  • Prophase: The phase of the cell cycle in which chromosomes are visible.
  • Metaphase: The phase of the cell cycle in which chromosomes are lined up in the cell.
  • Anaphase: The phase of the cell cycle in which the chromosomes are separated/ separating.
  • Telophase: The phase of the cell cycle in which the nucleus reforms after anaphase.
  • Cytokinesis: The phase of the cell cycle in which the cell membrane is fully separated between daughter cells.
  • Chromosome: A condensed structure in the cells of all organisms that is made up of DNA.
  • Haploid: A cell that contains one set of chromosomes (and only a single set of genes).
  • Diploid: A cell that contains both sets of homologous chromosomes.
  • Somatic: A body cell.
  • Sex cell: An egg or sperm; sex cells are haploid.
  • Zygote: A fertilized egg.

Duration

120–135 minutes/2–3 class periods

Prerequisite Skills

Prerequisite Skills haven't been entered into the lesson plan.

Materials

Related Unit and Lesson Plans

Related Materials & Resources

The possible inclusion of commercial websites below is not an implied endorsement of their products, which are not free, and are not required for this lesson plan.

Formative Assessment

  • View
    • Assess students as they sort the pictures of mitosis. Many groups should be able to think critically about the pictures and get most, if not all, of them in the proper order. Identify groups that struggle excessively and monitor them further during the drawing of the stages.
    • If using the PowerPoint during the drawing of the stages, there is ample time to move around the room to assess how students are doing as they draw each phase.
    • Collect only the final summary sheet, as students will need their drawing packet for the next day.

Suggested Instructional Supports

  • View
    Scaffolding, Active Engagement, Modeling, Explicit Instruction
    W: The introduction activity and the questioning during it set the stage for students to understand how mitosis fits into the lives of organisms.
    H: By comparing the largest animal ever to the small daphnia that they saw under the microscope during a previous lesson, students will be able to see the huge differences between living things but also the deep and surprising similarities.
    E: The inquiry-based sorting of the stages of mitosis activity will help to prime students for drawing the stages later. It also allows them to think critically about what types of steps must occur during the process of mitosis.
    R: The discussion following the sorting activity should help students to revise and evaluate their original presuppositions about the sequence of the phases. Additionally, the summary at the end of the lesson will help students distill down some of the key large ideas from the lesson.
    E: Students’ summary at the end of the lesson will allow them to express their understanding of the material. The drawing packet will also allow them to express their understanding but will not be collected until after the following lesson.
    T: This lesson is structured so that students are exposed to the stages of mitosis through hands-on manipulatives, written descriptions, and by physically drawing the phases. This variety will allow a greater number of students to proficiently access the information.
    O: The format of the drawing of the stages of mitosis is the same format that will be used in the upcoming lesson on meiosis. This similarity of formats will allow students to effectively make comparisons between the two processes.

Instructional Procedures

  • View

    Pose the following questions to students,

    • “What is the biggest animal ever to have lived?” (It is believed to be the blue whale; it is even larger than any dinosaur that has been found. They can reach over 100 feet long and weigh over 200 tons, which is 400,000 pounds.)
    • “If you had a huge balance and you put a blue whale on one side and daphnia on the other, how many daphnia would it take to balance the scale?” Have students pair or group and make a guess. The answer is: about 90,000,000,000 daphnia (2 milligrams) equal one blue whale (200 tons).
    • “Which animal has bigger cells, the daphnia or the blue whale?” (All living things—prokaryotes/bacteria excluded have cells of roughly the same size.)
    • “Which one started out as a single egg cell fertilized by a single sperm cell?” (both)
    • “Which one has gone through cell division more times?” (blue whale)

    Tell students that today they will learn about the way that cells grow and divide to make additional cells. The name of the process is mitosis. All living things (except bacteria) go through mitosis to grow bigger, then continue to carry out mitosis at a slower rate to replace some dead or damaged cells.

    Tell students that the goal of mitosis is to start with one cell that has all the DNA directions and end with two cells that each has a copy of all the DNA directions. Ask, “What is something in everyday life that you would need to sort through and organize if someone wanted a full set of what you have?” (Answers will vary; examples include papers, music, pictures, movies, and string for sewing.) Have one student give a detailed walkthrough of how s/he would give someone a set of such items. Prompt the student while s/he describes the process so that the following is clearly identified: copying of originals and sorting items into two piles. Tell students that cells need to do a similar type of sorting of their chromosomes (sets of DNA) when they divide during mitosis so that each cell gets a full set.

    Distribute copies (colored if possible) of Mitosis Phases Sorting to each group of students (S-7-4-2_Mitosis Phases Sorting.docx). The handout should be precut so that each group receives a pack of the five diagrams. Explain to students that the five diagrams are pictures of a cell sorting its chromosomes, but that they are not in order and that they should place them in what they think would be the proper sequence.

    After the groups have placed them into a reasonable order ask the class, “Which of the diagrams are you fairly confident you have in the correct spot and why?” (Answers will vary.) “Which of the diagrams did you have difficulty placing in the correct spot and why?” (Answers will vary.) The goal of this is to get students to critically look at the different phases and think about them before drawing them in the next activity. Write the following on the board: Prophase, Metaphase, Anaphase, Telophase, Cytokinesis. Have students make corrections to their sequence by putting them into this order, using the letters at the top of each diagram. Explain that this is the proper order and you will now walk them through each step as they draw.

    Hand out the Mitosis and Meiosis Drawing Packet (S-7-4-2_Mitosis and Meiosis Drawing Packet and KEY.docx). Ideally, give each student (or pair) a red, orange, dark blue, and light blue colored pencil or marker. Any colors work but it will be best for meiosis later if they use a pair of similar colors and another pair of similar colors (for example dark and light green and dark and light brown). Use the Drawing Mitosis PowerPoint presentation or draw each phase onto the board (S-7-4-2_Drawing Mitosis Presentation.pptx). Have students copy the pictures into their packet. At the onset, point out that two of the chromosomes should be large and two should be small, so that they can be distinguished from one another. If desired, additional concepts and vocabulary can be added to the notes section on the right side. Remind students that the different phases are all part of one continuous process and that in real life the cell doesn’t necessarily pause between each phase.

    When finished, ask students, “Why do cells go through mitosis?” (for growth and replacement of damaged cells) Tell students, “A typical adult human is made of approximately 100 trillion cells. How many cells does a person start with?” (one fertilized egg or zygote) “At least how many times does the process of mitosis have to happen to form an adult from a fertilized egg?” (100 trillion, plus much more to replace dead/damaged cells along the way)

    Have students write the following phases of mitosis on a piece of a paper:

    • Prophase
    • Metaphase
    • Anaphase
    • Telophase
    • Cytokinesis

    After each word, have students write a very brief (up to 4 words) summary of what happens in each phase of mitosis. Have students come up with a mnemonic device to remember PMATC in order. Have them write it on the bottom of their paper. Time permitting, have some students share their mnemonic devices. Collect their papers for assessment.

    Extension:

    • Students who may be going beyond the standards can add labeled figures to their mitosis drawing packet. Reasonable additional items include centrioles, spindle fibers, and centromeres. Students could find these additional items from their textbook, other textbooks, or an online search.
    • Give students who might need extra practice the printed diagrams that they sorted in the earlier activity. Students can copy the diagrams onto their sheet if they get behind the general pace of the class during the drawing of the stages.

Related Instructional Videos

Note: Video playback may not work on all devices.
Instructional videos haven't been assigned to the lesson plan.
DRAFT 05/12/2011
Loading
Please wait...