Science

Science
-Biology
-Chemistry
-Physics

Biology
Cells
There are many types of cells. For example : Squamous and cuticle in plants.
Q : Are cells smaller than atoms?
A : No! In fact, atoms are much smaller than cells and they itself contains them.
Definition of cell : the basic unit of life of all living things.
Parts of cell :
Plasma membrane
-made up of proteins and phospholipids ( Chemistry- Form 4 Chapter 3)
-semi-permeable to ions and organic molecules Example: OXYGEN, CARBON DIOXIDE 
-protects the cell from external environment.                

                                                                                                                       

-Regulate the movement of selective substances in and out of the cell.

Cell wall
-ONLY FOUND in plant cells.
-A rigid layer which surrounds the plasma membrane
-permeable
-Made up of CELLULOSE.
-Maintains shape
-Mechanical support
-plant cell will burst when excess water enters the cell without cell wall.

Mitochondria
-where oxidation of glucose takes place.
-Glucose transforms into ATP(Adenosine triphosphate) which is an energy.

Cytoskeleton
-a network of cisternae that holds together components of the cell.
-within the cytoplasm.

Cell reproduction
-Mitosis
-Meiosis

MITOSIS
-do not occur in gametes and spores(they take part in meiosis)
-occurs every 24 hours
-important to replace old cells in one's body.
-after division, both cells has 46 chromosomes (structures that are made up from DNA( deoxyribonucleic acid )
-only a part of the cell cycle( includes Mitotic phase and interphase)
-every mitotic phase takes about 80 minutes.

Stages of Mitosis
1)Prophase - the DNA condenses, organizes and the classic chromosomes' structure appear.
2)Prometaphase -microtubules attach themselves to the chromosomes.
3)Metaphase - the chromosomes align at the equator of the cell.
4)Anaphase - the chromatids are pulled away from its original form(chromosomes) by the microtubules   towards the poles( centrosomes ).
5)Telophase - the nuclear membrane forms around the newly formed chromosomes. Two nucleus forms
6)Cytokinesis - The cell separates into two daughter cells.



INTERPHASE (A part of the cell cycle)
-Separated into three parts:       G1------S------G2
o G1 (Gap 1) - Cell becomes active, parts of cell ( exp: Mitochondria ) doubles.
o S ( Synthesis phase ) - DNA( forms the chromosomes ) in the cell replicates.
o G2 ( Gap 2 ) - The cell finishes replicating. Two centrosomes appeared in the cytoplasm of the cell.

( Mitosis can start )

Kemunculan kafe siber di negara kita seumpama cendawan tumbuh selepas hujan. Keadaan ini memang mengharumkan nama baik negara kita sebagai negara yang maju dalam teknologi komputer. Pada zaman dahulu, nenek moyang kita hidup dalam dunia yang mundur daripada segi teknologi dan kafe siber belum wujud. Kini, kita hidup dalam dunia yang serba maju dan kemunculan kemunculan kafe siber bukan lagi isu katak ditimpa kemarau. Perbezaan antara dua zaman ini seumpama langit dangan bumi. Namun begitu, kemajuan ini yang begitu ketara juga mendatangkan keburukan yang tidak boleh dipandang rendah, termasuklah kemunculan kafe siber. Apakah keburukan yang didatangkan oleh kafe siber?

  Salah satu daripada keburukan yang didatangkan oleh kafe siber ialah kehilangan tumpuan pelajar dalam kelas. Hal ini kerana para pelajar berfikiran bahawa permainan komputer di kafe siber lebih menarik jika dibandingkan dengan pelajaran. Akibatnya, prestasi pelajar akan merosot kerana pelajar tidak menerima informasi yang disampaikan oleh gurunya dangan sepenuhnya. Para pelajar seharusnya menumpukan perhatian dalam kelas supaya mereka boleh menyerap ilmu pengetahuan dengan lebih efektif. Untuk merealisasikan keadaan ini, pihak kerajaan kita perlu mengurangkan bilangan kafe siber di negara kita supaya prestasi pelaja boleh diperbaikikan.

  Selain itu, kemunculan kafe siber menyebabkan kebanyakan pelajar ponteng sekolah. Kafe siber sudah menjadi tempat pelajar berpelesiran kerana ia seumpama penghibur terbaik pelajar. Keadaan ini seumpama dikenakan garam atas luka apabila para pelajar sanggup ponteng sekolah untuk mengunjungi kafe siber. Hal ini menunjukkan keseriusan impak kafe siber dalam kalangan pelajar. Mereka rela mengorbankan masa belajar mereka untuk mengunjungi kafe siber. Akibatnya, mereka gagal menyerap ilmu pengetahuan yang secukupnya. Bukan sekadar itu, terdapat segelintir pelajar yang dikenakan hukuman dibuang sekolah kerana memonteng sekolah. Namun begitu, mereka masih berkeras untuk mengunjugi kafe siber walaupun dihukum. Patutkah mereka mengorbankan masa depan mereka yang cerah sekadar untuk mendapat hiburan yang terhad?

   Di samping itu, kemunculan kafe siber akan memudaratkan kesihatan para pelajar. Hal ini sedemikian keran kebanyakan pengguna komputer, termasuklah para pelajar, tidak mengamalkan posisi  serta postur yang betul. Oleh itu, tulang belakang mereka mula membengkok kerana tekanan ke atasnya terlalu besar. Selain itu, monitor komputer juga memancarkan sinaran ultraungu yang boleh menjejaskan penglihatan pelajar. Itulah sebab kebanyakan pelajar pada hari ini mempunyai penglihatan yang lemah. Jika ditinjau dengan teliti, mata kita kurang berkelip apabila kita sedang  menggunakan komputer kerana kita tertarik oleh pancaran cahaya yang berwarna. Hal ini menyebabkan kita mengalami mata kering dan dijangkiti penyakit-penyakit yang lain seperti myopia dan hyperopia. Tambahan pula, kesan negatif pancaran cahaya komputer yang terlampau terang terhadap mata ditambahseriuskan apabil digabungkan dengan suasana gelap di dalam kafe siber. Oleh sebab itu, wajarlah para pelajar mengurangkan kunjungan mereka ke kafe siber.

   Lebih-lebih lagi, memang tidak boleh dinafikan bahawa kafe siber ialah salah satu sumber maklumat dan informasi yang bersifat negatif. Di kebanyakan kafe siber, komputer tidak mempunyai sekatan maklumat dan informasi yang negatif. Tambahan pula, para pelajar tidak akan diawasi oleh ibu bapa dan guru mereka. Mereka sering menggangap mereka sebagai pendalang mereka untuk melayari laman web yang disukai oleh mereka. Di kafe siber, mereka bebas melayari sebarang laman web yang terdapat dalam dunia media. Malangnya, mereka terdedah kepada sebarang informasi dan maklumat di kafe siber. Maka dalam jangka masa yang panjang, para pelajar yang pergi ke kafe siber untuk melayari Internet akan dipengaruhi oleh maklumat tersebut dan mereka akan mengalami kerosakan akhlak yang serius.

   Secara tuntasnya, kafe siber diwujudkan di Malaysia hanyalah untuk kebaikan orang ramai, Namun begitu, terdapat golongan yang menyalahgunakannya dan menjadikannya sebagai salah satu pihak yang disalahkan atas kerosakan akhlak orang ramai, terutamanya golongan pelajar. Kafe siber tidak patut dipersalahkan secara bulat-bulat kerana pihak-pihak lain seperti ibu bapa, pihak sekolah, rakan sebaya dan pihak kerajaan juga memikul tanggungjawab yang tertentu terhadap masalah dalam kalangan remaja. Walau bagaimanapun, setiap masalah pun ada cara penyelesaiannya, bak kata orang-orang tua, tiada kusut yang tidak selesai dan tiada keruh yang tidak jernih. Tindakan yang rasional perlulah dilaksanakan secepat mungkin terhadap kafe siber demi masa depan para pelajar.

Be Careful What You Wish For

Wish, in the dictionary it was said as a hope or desire for something. In the eyes of a normal person, wish can only be given by a god or a deity he believed in. However, wishes are also called as a bane in a boon. Besides the benefits given, it has its side effects and it is only the matter of light and serious. Therefore, wishes must be cautiously viewed and made. If a god or a deity appears before your eyes and they ask you about your wish, what should we do? Should we be convulsing with fear or should we assert our wish without thinking? At this point, allow me to explain the ambiguity surrounding this word with the great hope that all doubts about the word ‘wish’ would fade away.

When a wish is given to us, three crucial aspects or issues must be thought and considered. Firstly, our wish will have to include consideration for the improved welfare of our parents. They are the protectors and breadwinners of the family that grant us every necessity we need and more importantly they give us unconditional love and care. When we are in trouble, which comes to our aid? Will our friends, teachers or the society provide us with the assistance and support we need in hard times? Certainly our parents would be at the fore to support or assist us. Parents are pillars of strength for us when we need support and assistance most. Their care for us will never falter and their love is unquestionable. So, should we use our wish to repay our parents? I certainly would. So, my first wish would be for their wellbeing. I will wish that they would lead a healthy life for eternity.

Secondly, friends should also be considered and included in planning our wish. Close and loyal friends are often as caring and supportive as our brothers and sisters because most of them are our peers and may have had similar experiences both good and bad. Even when they are unable to offer solutions, their patience and understanding, lending their ears would help much to dissipate anguish when we are troubled. Mostly, they would help us confront obstacles not much different to those that we face in our quest for success in our future. As the saying goes, ‘A friend in need is a friend indeed'. They arouse the spirit of competing, the lust to strive for improvement and they build hope in our lives. In our daily lives, they accompany us. They laugh together. They provide us the shoulder to lean on during hard times. They bring us joy and offer us help when we are in sorrow. In our daily lives, the company we keep is critical in moldings the way we become as we grow up. Even our teachers can also be considered as our friends. At school, they may be our mentors and gurus, but when we leave school, their influence will stay with us, years after we leave the school. Our enemies are also our friends if we see them in good light. Basically, everyone is our friend. Therefore, we should always wish for the best not only for my friends but also for my foes.

Thirdly, a wish that is granted to us, undoubtedly, will have our best interest. However, the impact brought upon us by our wishes may unwittingly have negative impact on others. A good wish must not bring harm to anyone and it should be beneficial to us. It would be wonderful if our wishes could provide for positive effects on ourselves as well as those around us, near or far. In an ideal ‘utopia’, it would be unusually fabulous if such a wish can bring benefit to us and as well as others.

How do we make a good wish? It may be heart searching and mind boggling question. Still, it is yet to be answered. Deep consideration is important. We should ponder over it repeatedly before wishing for something as the upshot of our wish may have adverse consequences. We should not jump the gun or we may have to pay the piper. We must think about its benefits and disadvantages, if any, about our wish. It is indeed foolish and selfish to wish for something that may have negative effects upon others and benefit ourselves only. No sane person on Earth would like to rain destruction upon mankind and in that process, annihilate themselves. For instance, a wish for lots of money may bring a short-lived happiness because money cannot buy happiness. Furthermore, his or her substantial wealth can also give rise to increased greed and selfishness in the people around him or her. Therefore, monetary gains may not always provide positive outcomes and happiness.

Besides that, many people may think that immortality and finding the key to the fountain of youth should bring happiness and a meaningful life, much like the feel good fairy tales that are dramatized in the movies. However, it can be an untrue scenario. No one can be an island; we need family and friends around us in order to lead a happy and fruitful life. When those close to us passes on and we watch helplessly, we may not feel the pain of dying but we will always feel the pain of losing our loved ones. The excruciating agony and sorrow watching our loved ones die is far worse than dying. Do we actually want that? Some people may say that wishing for immortality for everyone is the best way to avoid the sorrow of losing our loved ones. It may seem true but in the long run, it may rain destruction upon mankind. It could be opening a can of worms, one good wish leading to perpetual problem issues for all.

From the various issues discussed above, we may conclude that immortality and agelessness will only bring more grief and disorder to our halcyon world. Making a good wish is indeed a most challenging and yet exciting task. It is especially difficult when we would very much like to find one that is both rewarding to ourselves and our loved ones and yet have no adverse impact on others outside our circle.

The movie X- men and other fantasy stories have affected mankind in their wish-choosing. Men may start imagining about the extraordinary power they could have like the characters in movies and stories. But wishing for non existence of such powers may cause us to look like fools who continuously make wishes that are unattainable. Wishes are mere desires. We should simply stop wishing and work towards accomplishing what we wish for. Otherwise wishes will only be dreams forever. Let us not live in a dream world, let’s get real.

In a nut shell, wish must be cautiously made because it will bring permanent damage if we do not do so. Therefore, be careful what you wish for.