Ideally this activity should occur after instruction on mitosis but before instruction on meiosis. I used it as a warm-up to the lesson on Meiosis. Students should use their critical thinking skills to determine the difference in the products of these two processes.
- asexual reproduction
- sexual reproduction
APH Life Science Tactile Graphics
- The only preparation necessary is to have a set of the Life Science Tactile Graphics for each student.
- Tape together the Meiosis I and Meiosis II pages for easier access. See instructions for this in the procedure.
- As students walk in the room, set out for each student the mitosis page and the meiosis pages from the Life Science Tactile Graphics kit. Mitosis on the left side of the desk and meiosis I and meiosis II (connected) on the right. It may be useful to temporarily tape the 2 meiosis pages (meiosis I and meiosis II together so that students can decipher the stages in order. Tape the meiosis I page on top of the open meiosis II page in the middle.
- Tell students that they will compete to answer a question using these graphics. Explain that students (either alone or in groups) will compare the results of the 2 processes by looking at the chromosomes in the beginning of each process and at the end.
- Have students find the prophase stage of mitosis and the prophase stage of meiosis I. Ask students to consider this stage and the final stage of each process as they compare the result of mitosis with the result of meiosis. Make sure that they are considering telophase II (from meiosis II) as they look to the final stage of the entire meiosis process (and not telophase I from meiosis I )
- Students will compare the processes. The goal is that students will understand that the process of mitosis produces cells identical to the original with the same number of chromosomes but that meiosis halves the number of chromosomes. Only give guidance as necessary. I always tell my students that I like for them to struggle a bit. Hopefully students will experience an “Aha!” moment as they figure this out themselves.
- Have the student(s) who has figured it out raise their hand to be acknowledged but give all students enough time to consider the question before the discussion.
- We will learn today that Meiosis is the process by which sex cells are produced. Why would this process produce cells with only half of the DNA?
- Before both the process of mitosis and the process of meiosis the DNA is replicated. How does the process of meiosis end up producing cells with only half the DNA while the process of mitosis produces cells identical to the original cell?
Students can work alone or in groups.
High School – Inheritance and Variation of Traits
LS1.A: Structure and Function
- All cells contain genetic information in the form of DNA molecules. Genes are regions in the DNA that contain the instructions that code for the formation of proteins. (secondary to HS-LS3-1) (Note: This Disciplinary Core Idea is also addressed by HS-LS1-1.)
LS1.B: Growth and Development of Organisms
- In multicellular organisms individual cells grow and then divide via a process called mitosis, thereby allowing the organism to grow. The organism begins as a single cell (fertilized egg) that divides successively to produce many cells, with each parent cell passing identical genetic material (two variants of each chromosome pair) to both daughter cells. Cellular division and differentiation produce and maintain a complex organism, composed of systems of tissues and organs that work together to meet the needs of the whole organism. (HS-LS1-4)
LS3.A: Inheritance of Traits
- Each chromosome consists of a single very long DNA molecule, and each gene on the chromosome is a particular segment of that DNA. The instructions for forming species’ characteristics are carried in DNA. All cells in an organism have the same genetic content, but the genes used (expressed) by the cell may be regulated in different ways. Not all DNA codes for a protein; some segments of DNA are involved in regulatory or structural functions, and some have no as-yet known function. (HS-LS3-1)
By Laura Hospitál
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