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My name is Poon Cheng Moh. I have been teaching biology in SMK(P) Raja Zarina, Port Klang for 26 years. I sincerely hope that this blog on SPM Biology will be useful to both teachers and students.

Friday, May 8, 2015

How a cell cycle works



MITOSIS & CYTOKINESIS



http://highered.mheducation.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120073/bio14.swf::Mitosis%20and%20Cytokinesis

Prophase
• The chromosomes in the nucleus condense and become more tightly coiled.
• Each chromosome now consists of a pair of sister chromatids joined together at the centromere.
• In the cytoplasm, the spindle fibres begin to form and extend between the centrioles.
• Each pair of centrioles then migrates to lie at the opposite poles of the cell. The chromatids are attached to the fibres of the spindle by their centromeres.
• At the end of prophase, the nucleolus disappears and the nuclear membrane disintegrates.

Metaphase
• Metaphase begins when the centromeres of all the chromosomes are lined up on the metaphase plate, an imaginary plane across the middle of the cell.
• The mitotic spindle is now fully formed.
• The two sister chromatids are still attached to one another at the centromere.
• Metaphase ends when the centromere divide.

Anaphase
• During anaphase, the two sister chromatids of each chromosome separate at the centromere.
• The sister chromatids are pulled apart to the opposite poles by the shortening of the spindle fibres.
• Once separated, the chromatids are referred to as daughter chromosomes.
• By the end of anaphase, the two poles of the cell have complete and equivalent sets of chromosomes.

Telophase
• Begins when the two sets of chromosomes reach the opposite poles of the cell.
• The chromosomes start to uncoil and revert to their extended state (chromatin).
• The chromosomes become less visible under the microscope.
• The spindle fibres disappear and a new nuclear membrane forms around each set of chromosomes.
• The nucleolus also reforms in each nucleus.
• The process of mitosis is now completed.

Tuesday, March 10, 2015

FORMAT AMALI BIOLOGI SPM (4551/3A)

***AMALI BIOLOGI SPM (4551/3A) DITANGGUHKAN KE TAHUN 2016

Bil.
Perkara
KERTAS 3 (4551/3A)
1
Jenis instrumen
Ujian Amali
2
Jenis item
Item subjektif : Item berstruktur
3
Bilangan soalan
2 soalan (Jawab semua)
4
Jumlah Markah
30    (Wajaran 16.7%)
5
Cara Memberi Respons
Ditulis pada ruang dalam kertas soalan
6
Tempoh Ujian
1 jam 45 minit (Termasuk 15 minit masa    merancang)
7
Konstruk
·        Kemahiran proses sains
·        Kemahiran manipulatif
8
Pemarkahan
Pemarkahan secara analitikal dan holistik berdasarkan rubrik penskoran
9
Cakupan Konteks
Bidang pembelajaran Tingkatan 4 dan    Tingkatan 5