Teaching the Concepts of Meiosis D2.2, D3.1, D3.4

1. Teaching the Concepts of MeiosisD2.2, D3.1, D3.4 KhagenDhakal Rosa Rossi

2. Introduction to Meiosis If someone told you that your body developed from the fertilization of a unique sperm and unique egg you might think they are joking! Truth is, they aren’t! But there is more to the story than an egg and a sperm. To put it in simple terms (for now) the fertilized egg , which we call a zygote, undergoes successive cell division. What is successive cell division? To better understand this we will explore the process of Meiosis.

3. Lesson Sequence • Lesson 1: Meiosis and Sexual Reproduction • Sex Chromosomes and Phases of Meiosis • Lesson 2: New Gene Combinations • Crossing Over • Lesson 3: Atypical Chromosome Numbers • Trisomy, Down Syndrome, Non-Disjunction • Lesson 4: Damage to Chromosome Structure • Mutation, Translocation, Deletion, duplication, Inversion • Lesson 5: Genetic Testing • Prenatal Testing, Newborn Screening

4. Curriculum Expectations • D2.2 investigate the process of meiosis, using a microscope or similar instrument, or a computer simulation, and draw biological diagrams to help explain the main phases in the process • D3.1 explain the phases in the process of meiosis in terms of cell division, the movement of chromosomes, and crossing over of genetic material • D3.4 describe some genetic disorders caused by chromosomal abnormalities (e.g., non-disjunction of chromosomes during meiosis) or other genetic mutations in terms of chromosomes affected, physical effects, and treatments

5. Inquiry Based learning • http://www.youtube.com/watch?v=MqaJqLL49a0

6. Inquiry Based Learning: Teaching concept, process and skills through Virtual Laboratory, mnemonics and story telling • Students will explore meiosis through a virtual laboratory • Students will use an inquiry based approach to manipulate chromatids in the cell. • Students will interactively learn about the key processes associated with meiosis including: crossing over, and random assortment of chromosomes

7. Inquiry Based Learning: Ascospores Laboratory • Student will have the opportunity to perform an in class laboratory to observe meiosis through their given slides. • Through Pearson Education Lab Bench students will be able to explore the phases of meiosis in ascospores. • Students can manipulate various features within the laboratory, which will assist them in their investigation and follow up questions • Teachers can use the follow up questions as an assessment tool for student understanding 1. In the photo, how many asci marked with an X show no evidence of crossing over?

8. Potential Student Difficulties • Students may have difficulty differentiating between the different phases of meiosis as well as stages I and II. • Concept can be taught by Mnemonics, story telling (linking primary discourse) for process and reading skills (see slide 6) • Unlike prophase I, prophase II is not preceded by a round of DNA replication-abstract concept that may by difficult for students to picture • Abstract concept- Separation of sister chromatids in anaphase II • Once separated, sister chromatids are considered individual chromosomes • Telophase II and cytokinesis produces 4 HAPLOID DAUGHTER CELLS • Similarity- Confusion may arise between mitosis and meiosis processes • Recognizing and differentiating between mutations: translocation, deletion, duplication, and inversion

9. Solutions to student difficulties • Virtual laboratory can help make the phases more concrete • Clarifying prior knowledge and confusion and linking with the topic eases the learning process. • Analogy and story telling to teach sequence, process (for example wrestling game) by linking with primary discourse and prior knowledge can enhance the skills to learn • Teachers can create Venn diagrams and/or T-charts as a class to differentiate between the two cell divisions: mitosis and meiosis • In class diagrams can assist the students during activities and help them remember the concepts over time • During the Ascospores laboratory emphasize the key differences between each phase • In prophase I, homologous chromosomes exchange genetic information • Creating a mnemonic for the different chromosome mutations • Research different articles on atypical chromosome numbers • Famous PEOPLE Players-example of developmental disabilities

10. Safety considerations • Considering the nature of adolescents, they should be well monitored while they are in the virtual lab activity in order to make sure that they are doing the job as intended • Unsafe websites should be blocked either by appropriate settings on browser or through school’s server • Volunteers who are selected for the role play (for example in the wrestling game) should be encouraged to sign a safety contract • Students demonstrate that they have the knowledge, skills, and habits of mind required for safe participation in science activities and laboratories when they (Ontario Science Curriculum, 2008): • maintain a well-organized and uncluttered work space; • follow established safety procedures; • identify possible safety concerns; • suggest and implement appropriate safety procedures; • carefully follow the instructions and example of the teacher; • consistently show care and concern for their own safety and that of others

11. Practical applications • Students will explore through journals on how meiosis relates to topics such as genetic testing and damage to chromosome structure • Prenatal screening; newborn screening • Atypical chromosome Numbers • Trisomy 21-Down syndrome; Trisomy 18-Edwards syndrome XXY-Klinefelter syndrome

12. Differentiated assessment • Assessment will be on ongoing • Accessing prior knowledge before, during, and after instruction using pre-assessment tests and activities • Students are differentiated in their knowledge (concept of terminologies, meiosis) and skills (reading books and interpreting figures to identify differences/linking ideas between mitosis and meiosis, and meiosis I and II. • Student use of their own ideas to express a concept, process and skills (it can be different than wrestling game) • The speeds at which they process new learning and connect it to prior knowledge will be assessed • Students also differ in the ways they most effectively demonstrate their progress. • Self and formative assessment and peer observation • Eagerness to participate and contribute in role-play • Assessment of learning from youtube video (for the kinesthetic learners)