Class began with an example of why mitosis is important: a video showing how salamanders can regenerate lost limbs:

After the video, we worked through a PowerPoint providing students with important vocabulary related to mitosis, with images related to the vocabulary to help reinforce student learning.  Students were encouraged to memorize “PMAT” – an acronym for Prophase, Metaphase, Anaphase, and Telophase which may prove useful on the Biology EOC.  We also discussed the difference between the Washington State Science Standards and the Next Generation Science Standards governing mitosis.  Although Washington State has adopted the NGSS, students are still tested on the WSSS and therefore must navigate between both worlds.  The WSSS (9-11 LS1H) expects students to describe and model the process of mitosis, in which one cell divides, producing two cells, each with copies of both chromosomes from each pair in the original cell.  The NGSS mitosis standard (HS-LS1-4) requires that students use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.  To help students achieve mastery of the content standards, students were introduced to the Mitosis Project.  The final slide of the project includes a list of 12 different projects for students (working alone or in pairs) to chose from.  Students learned a bit about each project and then had time to decide which project they would like to pursue.  We will formally launch the project tomorrow.

After wrapping up our work for now on the Chromosome Project, we transitioned to studying how cells divide.  Mitosis, or somatic cell division, involves the division of one cell into two after all of the components of the original cell (including the DNA!) divide into two sets.  We began by watching a Crash Course video about mitosis:

After the video, students were assigned to read pages 46-51 of chapter 4 (Cellular Reproduction: Multiplication By Division) of Inside the Cell.   Students then answered the following questions in their lab notebooks:

1. Explain the purpose of mitosis.
2. Which cells undergo mitosis?
3. Describe the phases of mitosis in detail (words and/or drawings).
4. Explain what happens when cells divide uncontrollably.  List the known causes of uncontrolled cell division.

This unit is focused specifically on NGSS Standard HS-LS1-4: Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms. Students have previously been assessed on their understanding of how cellular expression of specific gene products (proteins) can result in unique cell types, and groups of unique cell types can form tissues.  Students learned about body structure and organization during Unit 3, including the organization of cells into tissues and organs.  In this mini-unit, students will be able to clearly connect the process of mitosis (cell division) with tissue organization and organism development.