pearls bio perak state

PEDAGOGY ENHANCEMENT AND REINFORCEMENT OF LEARNING STRATEGIES (PEARLS)

BIOLOGYCell Division

CASE - Cell division

BACKGROUND Cell division is one of the popular topics frequently

asked in examinations. But students usually encounter difficulties in tackling the question correctly.

When teaching mitosis and meiosis , students always get confused between chromatin , chromatids and chromosomes. They tend to use incorrect terms for describing different forms of chromosome.

Students are also facing problem to count the chromosomal number in the cell especially in meiosis.

DISCUSSION

How to solve the problems?

Suggestion 4 solutions

Solution 1

Show the diagrams and explain the structure of chromatin, chromatid and chromosome so that the students are able to differentiate their structure.

1. Using different stages of mitosis and meiosis to show the location of chromatin, chromatid and chromosome.

2. Students are also explained that chromatid are also known as chromosome at the end of mitosis and meiosis.

Solution 2

Mitosis

Telophase

Prophase Metaphase

Anaphase

Meiosis

Anaphase 1Metaphase 1Prophase 1 Telophase 1

Meiosis

Anaphase 2Metaphase 2Prophase 2 Telophase 2

Students are given several diagrams of different stages mitosis and meiosis and they

are asked to determine diploid and haploid number of chromosomes.

Solution 3

2n = ______

n = ______

2n = ______

n = ______

2n = ______

n = ______

2n = ______

n = ______

Solution 4

Solution 4 Using models in explaining the structure of

chromosome Suggested materials: Marble,two colours of plasticine,manila card Procedure:

1. Students are asked to work in pairs.2. Student are asked to use two different colours of plasticine to form cylinder-shaped structure.3. Both cylinders are then crossed together and the marble is put at the crossing point.4. Place the model on the manila card to be displayed to other students.

Conclusion

All the four solutions given are subjective. It depends on students’ capabilities and can

be altered. Teachers can use different solution to different sets of student and situation.

Teachers may develop and elaborate the ideas of the solution according to teacher’s creativity.