Transcript Concept presentation meiosis revised rosa khagal

TEACHING THE CONCEPTS OF
MEIOSIS
D2.2, D3.1, D3.4
Khagen Dhakal
Rosa Rossi
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!
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
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Lesson 1: Meiosis and Sexual Reproduction
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Lesson 2: New Gene Combinations
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Trisomy, Down Syndrome, Non-Disjunction
Lesson 4: Damage to Chromosome Structure
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Crossing Over
Lesson 3: Atypical Chromosome Numbers
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Sex Chromosomes and Phases of Meiosis
Mutation, Translocation, Deletion, duplication,
Inversion
Lesson 5: Genetic Testing
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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
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INQUIRY BASED LEARNING
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http://www.youtube.com/watch?v=MqaJqLL49a0
INQUIRY BASED LEARNING: TEACHING CONCEPT,
PROCESS AND SKILLS THROUGH
VIRTUAL LABORATORY, MNEMONICS AND STORY
TELLING
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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
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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
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Students may have difficulty differentiating between the
different phases of meiosis as well as stages I and II.
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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
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Concept can be taught by Mnemonics, story telling (linking primary
discourse) for process and reading skills (see slide 6)
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
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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
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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
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Students will explore through journals on how
meiosis relates to topics such as genetic testing and
damage to chromosome
structure
Prenatal screening; newborn
screening
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Atypical chromosome Numbers
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Trisomy 21-Down syndrome;
Trisomy 18-Edwards syndrome
XXY-Klinefelter syndrome
DIFFERENTIATED ASSESSMENT
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Assessment will be on ongoing
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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.
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Accessing prior knowledge before, during, and after instruction
using pre-assessment tests and activities
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)