TEACHING THE CONCEPTS OF MEIOSIS

D2.2, D3.1, D3.4 Khagen Dhakal

Rosa Rossi

INTRODUCTION TO MEIOSISIf 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.

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

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

INQUIRY BASED LEARNING http://

www.youtube.com/watch?v=MqaJqLL49a0

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

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?

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

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

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

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

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)