Presentation on theme: "Teaching the Concepts of Meiosis D2.2, D3.1, D3.4"— Presentation transcript:
1Teaching the Concepts of Meiosis D2.2, D3.1, D3.4 Khagen DhakalRosa Rossi
2Introduction 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! In reality, they are not! 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.
3Lesson Sequence Lesson 1: Meiosis and Sexual Reproduction Sex Chromosomes and Phases of MeiosisLesson 2: New Gene CombinationsCrossing OverLesson 3: Atypical Chromosome NumbersTrisomy, Down Syndrome, Non-DisjunctionLesson 4: Damage to Chromosome StructureMutation, Translocation, Deletion, duplication, InversionLesson 5: Genetic TestingPrenatal Testing, Newborn Screening
4Curriculum 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 processD3.1 explain the phases in the process of meiosis in terms of cell division, the movement of chromosomes, and crossing over of genetic materialD3.4 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
6Inquiry Based Learning: Teaching concept, process and skills through Virtual Laboratory, mnemonics and story tellingStudents will explore meiosis through a virtual laboratoryStudents will use an inquiry based approach to manipulate chromatids in the cell.Students will interactively learn about the key processesassociated withmeiosis including:crossing over, andrandom assortmentof chromosomes
7Inquiry 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 questionsTeachers can use the follow up questions as an assessment tool for student understanding1. In the photo, how many asci marked with an X show no evidence of crossing over?
8Potential 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 pictureAbstract concept- Separation of sister chromatids in anaphase IIOnce separated, sister chromatids are considered individual chromosomesTelophase II and cytokinesis produces 4 HAPLOID DAUGHTER CELLSSimilarity- Confusion may arise between mitosis and meiosis processesRecognizing and differentiating between mutations: translocation, deletion, duplication, and inversion
9Solutions to student difficulties Virtual laboratory can help make the phases more concreteClarifying 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 learnTeachers can create Venn diagrams and/or T-charts as a class to differentiate between the two cell divisions: mitosis and meiosisIn class diagrams can assist the students during activities and help them remember the concepts over timeDuring the Ascospores laboratory emphasize the key differences between each phaseIn prophase I, homologous chromosomes exchange genetic informationCreating a mnemonic for the different chromosome mutationsResearch different articles on atypical chromosome numbersFamous PEOPLE Players-example of developmental disabilities
10Safety 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 intendedUnsafe websites should be blocked either by appropriate settings on browser or through school’s serverVolunteers who are selected for the role play (for example in the wrestling game) should be encouraged to sign a safety contractStudents 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
11Practical applications Students will explore through journals on how meiosis relates to topics such as genetic testing and damage to chromosomestructurePrenatal screening; newbornscreeningAtypical chromosome NumbersTrisomy 21-Down syndrome;Trisomy 18-Edwards syndromeXXY-Klinefelter syndrome
12Differentiated assessment Assessment will be on ongoingAccessing prior knowledge before, during, and after instruction using pre-assessment tests and activitiesStudents 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 assessedStudents also differ in the ways they most effectively demonstrate their progress.Self and formative assessment and peer observationEagerness to participate and contribute in role-playAssessment of learning from youtube video (for the kinesthetic learners)