Cikgu Naza

Influenza

2012-01-25T15:34:00.003+08:00

Influenza atau flu adalah penyakit berjangkit disebabkan oleh virus influenza.

Virus influenza.

Terdapat 3 jenis virus influenza iaitu A, B dan C. Ketiga-tiga ini boleh menjangkiti manusia. Virus influenza A adalah paling berbahaya kerana boleh menjangkiti haiwan dan manusia. Virus influenza A boleh menjalani mutasi (perubahan genetik) dan menghasilkan virus influenza jenis baru dan lebih berbahaya. Ini akan mencetuskan kejadian epidemik dan pandemik influenza.

Adakah influenza sama dengan demam selsema?

Tidak.

Walaupun kedua-duanya mempunyai gejala yang hampir sama tetapi influenza menyebabkan gejala dan tanda-tanda yang lebih teruk serta boleh menyebabkan komplikasi yang mengancam nyawa.

Perbandingan antara influenza dan deman selsema:

Tanda & Gejala	Influenza (Flu)	Demam Selsema (Common Cold)
Demam	Tinggi. Biasanya melebihi 38°C.	Kurang dari 38°C.
Letih lesu	Teruk dan boleh berlarutan hingga 2 ke 3 minggu.	Sangat ringan.
Sakit otot / sakit sendi	Sederhana ke teruk.	Ringan.
Batuk	Batuk teruk, tidak berkahak pada peringkat awal.	Tiada / Ringan.
Hidung berair / berhingus	Tiada / Ringan.	Teruk.
Bersin	Kerap.	Tidak kerap.
Sakit tekak	Sederhana ke teruk.	Tiada / Ringan.
Sakit kepala	Sederhana ke teruk.	Ringan.
Penyebab	Virus influenza A, B atau C.	Adenovirus, rhinovirus, parainfluenza virus, corona virus dan lain-lain.

Apakah rawatan bagi influenza?

Tiada rawatan khusus untuk influenza. Rawatan yang diberikan adalah rawatan simptomatik sahaja.

Anda dinasihatkan untuk mengambil tindakan-tindakan berikut:

Mengambil ubat demam seperti paracetamol untuk melegakan demam dan sakit kepala.
Minum air atau minuman suam bagi melegakan sakit tekak dan batuk.
Amalkan pemakanan seimbang dan tidur atau rehat yang secukupnya.
Hindarkan stress kerana ini akan melemahkan sistem pertahanan badan.
Jika tanda dan gejala berlarutan atau tambah teruk dapatkan rawatan di klinik atau hospital.

Bagaimana jangkitan influenza boleh dielakkan dari merebak?

i) Jika anda bersin atau batuk:

Tutup mulut dan hidung dengan tisu atau sapu tangan.
Buang tisu yang digunakan ke dalam tong sampah.
Jangan berkongsi sapu tangan.
Basuh tangan dengan sabun selepas batuk dan bersin. Juga basuh tangan dengan bersih setelah menyentuh bahan mentah, permukaan tercemar, muka, hidung, telinga dan lain-lain anggota badan.

ii) Pakai penutup mulut dan hidung (mask) untuk mengelakkan jangkitan influenza.

iii) Elakkan dari berada di tempat-tempat awam jika anda dijangkiti influenza.

Apakah perbezaan antara ubat antiviral dan vaksin influenza?

Ubat antiviral adalah ubat bagi merawat pesakit yang dijangkiti virus. Pemberian ubat antiviral pada masa yang betul akan dapat mengurangkan impak gejala dan tanda penyakit serta mengurangkan kemungkinan komplikasi penyakit.

Vaksin diberi sebagai langkah pencegahan. Vaksinasi menggunakan vaksin influenza yang ada di pasaran hanya untuk memberi perlindungan kepada individu dari mendapat jangkitan.

Kementerian Kesihatan Malaysia menyarankan mereka yang akan melawat negara yang sedang mengalami musim sejuk dan mereka yang akan mengerjakan haji dan umrah di Mekah agar mendapatkan suntikan vaksin influenza. Suntikan boleh diperolehi dari klinik atau hospital swasta tertentu.

Pastikan anda dapat membezakannya!

Anda haruslah memahami dan dapat membezakan istilah-istilah yang digunakan berkaitan dengan influenza:

Avian Influenza.
Avian influenza atau selsema burung adalah sejenis penyakit berjangkit yang biasanya berlaku di kalangan ayam, itik dan burung (unggas). Ia juga boleh menjangkiti manusia.

Epidemik influenza.

Epidemik influenza adalah kejadian wabak influenza yang menyerang sekumpulan penduduk di sesuatu lokasi atau negara.

Pandemik influenza.

Pandemik influenza adalah wabak influenza yang menyerang sebahagian besar dari penduduk dunia. Ia berlaku akibat kemunculan virus influenza baru yang mana penduduk dunia tidak mempunyai daya ketahanan badan bagi melawan virus tersebut. Vaksin influenza yang sedia ada tidak dapat melindungi serangan virus pandemik influenza.

Sumber: Pamplet Kementerian Kesihatan Malaysia.

2012: New Malaysian Coins & New Money Series

2012-01-20T00:41:00.005+08:00

New Malaysian coins released (issued into circulation
from 16th January 2012 onwards)

For more details of security feature & technical specifications,
please visit Bank Negara Malaysia

Salary 2012

2011-12-29T18:49:00.002+08:00

Schedule of salary payment (government's staff, Malaysia) for the year 2012, as below;

January → 16th January 2012, Monday .
February → 23rd February 2012, Thursday.
March → 22nd March 2012, Thursday.
April → 25th April 2012, Wednesday.
May → 23rd May 2012, Wednesday.
June → 25th June 2012, Monday.
July → 25th July 2012, Wednesday.
August → 13th August 2012, Monday.
September → 25th September 2012, Tuesday.
October → 22nd October 2012, Monday.
November → 06th November 2012, Tuesday.
December → 18th December 2012, Tuesday.

Guide To Healthy Eating

2011-11-16T20:21:00.007+08:00

Enjoying a variety of foods

Eat food based on the Malaysian Food Pyramid.
Vary the types of food from each level of the Food Pyramid.
You are encouraged to select different menu each day.
Try eating foods that you don't normally eat.

Enjoying more fruit and vegetables

Eat at least 1/2 cup of vegetables during each meal.
Eat at least one type of fruit during each meal.
Eat different types of fruits.
Choose meals with fruit and vegetables.
- Example: nasi kerabu, nasi ulam, fruit pudding, fruit/vegetable salad, vegetable salad with peanut sauce.
Eat fruit as a snack.
Eat salad and ulam with your meal.

Reducing fried and fatty foods

Choose white rice instead of nasi beriani, nasi minyak and nasi lemak.
Choose roasted, baked, steamed or boiled foods instead of fried foods.
Reduce the intake of oily gravy by removing excess oil.
Limit the intake of internal animal organs (liver, brains, lungs, spleen, stomach) and egg yolk.
Eat lean meat and skinless chicken.
Choose foods that do not contain coconut milk.
Use less butter or margarine on bread/biscuit/corn.
When ordering food, request for less butter/margarine.

Enjoying whole grains, legumes, nuts and seeds

Eat whole grain based foods for breakfast like oats, corn and capati.
Choose bread, pita bread and whole grain breakfast cereals and biscuits.
Replace or mix white rice with brown rice.
Eat legume based food like bean curd, soya bean cake and baked beans a few times a week.
Eat nuts/seeds a few times a week (Example: basil seed in drinks or cakes sprinkled with sesame seeds).
Source of whole grains, legumes, nuts and seeds.
- Whole grains
  1. Brown rice.
  2. Oats.
  3. Corn.
  4. Wholemeal bread/biscuits with rye, wheat, oat, corn and barley.
- Legumes
  1. Mung beans.
  2. Dhal.
  3. Chickpeas.
  4. Red bean.
  5. Soya bean.
- Nuts
  1. Peanut.
  2. Chestnut.
  3. Cashew nut.
  4. Almond.
  5. Pistachio.
- Seeds
  1. Sesame seed.
  2. Dried seeds (watermelon/pumpkin/sunflower seeds).
  3. Lotus seed.
  4. Basil seed.

Reducing sugar intake

Replace sweet drinks, syrup, cordial and carbonated drinks with plain water.
Replace sweet cakes, biscuits, candies or chocolates with fresh fruit.
Choose foods with less sugar. Read label for sugar content.
When ordering drinks, request for less sugar or sweetened condensed milk.

Choosing safe food

Choose a clean eating place.
Make sure food handlers practise good personal hygiene.
Make sure the food is clean and safely handled.
Avoid eating contaminated foods.
Choose fresh or freshly cooked foods.
Avoid eating burnt food.
Make sure the food packaging, box and tin are in good condition.
Limit the intake of food containing preservatives.
Limit the intake of food containing artificial colouring.
Avoid foods fried using oil that has been repeatedly used.

Ministry starts disbursing RM100 allowance for students

2011-11-11T02:12:00.002+08:00

Source: The Star Online, Thursday November 10, 2011

By A. RUBAN

KUALA LANGAT: The Education Ministry has started disbursing the RM100 allowance to some 5.5 million school students in schools nationwide.

Its minister, Tan Sri Muhyiddin Yassin, said the monies were currently being deposited in the schools' Bank Simpanan Nasional savings account.

The allowances are currently given to students from Year One up to Form Four of the 2011 session, the Deputy Prime Minister said.

"Allowance for students entering Year One and Form One of the 2012 session will only be given in January next year because we do not know which school they would go to," he told reporters when visiting lecturers and students at the Selangor Matriculation College here Thursday.

[Science Form 1] Nucleus, vacuole & cell membrane

2011-11-10T23:31:00.003+08:00

Cells have many structures in them called organelles. These organelles are like the organs in a human body and each of them has specific functions to help the cell it is in survive.

Plant cells and animal cells have different organelles to perform specific functions. For example, plant cells have chloroplasts and a cell wall, whereas animal cells do not have these two organelles.

Do you know the functions of each cell structure? To gain a better understanding of cell structures and their respective functions.

Cell structure and it's function

Nucleus
Function - It is responsible for directing and controlling the activities of the cell, in the same way that your brain directs and controls the activities of your body.

It is also carries genetic information, or the blueprints on how cells and organisms should be structured.
Vacuole
Function - Vacuoles are small sacs filled with food and water. They are used by cells as storage tanks. All plant cells have vacuoles, but not all animal cells do.

The primary place where plants store water is within its vacuoles. When a plant's vacuoles are filled with water, they become plump, giving the plant its strength. What happens when you do not water a plant? It begins to wilt and become softer. This is because the vacuoles found inside the plant cells are running out of water.
Cell membrane
Function - This is a thin layer that surrounds a cell.

In order for a cell to remain healthy, it needs to be able to bring in food, and get rid of waste. The cell membrane has small openings or doorways that allow the cell to move materials in and out of it.

[Science Form 3] About Blood

2011-11-10T02:21:00.005+08:00

The transport system in humans is called the circulatory system, which is made up of heart and blood vessels.

The functions of the blood circulatory system are to:

supply oxygen to all body cells and eliminate carbon dioxide,
transport waste products

Structure of the heart

Oxygen-rich blood (red color)

Oxygen-poor blood (blue color)

AO = Aorta
LA = Left atrium
LV = Left ventricle
PA = Pulmonary artery
RA = Right atrium
RV = Right ventricle

The heart is a muscular structure that contracts in a rhythmic pattern to pump blood. It si the size of your fist and has four chambers:

right atrium
right ventricle
left atrium
left ventricle

The space in the atrium is smaller than that in the ventricle. The wall of the ventricle is thicker and stronger than that of the atrium.

Valve TRICUSPID - Prevents blood in the right ventricle from flowing back to the right atrium.

Valve BICUSPID - Prevents blood leaving the heart from flowing back.

Learning in English to continue

2011-11-07T10:05:00.012+08:00

Source: The Star
Saturday, 05th November 2011

PUTRAJAYA: Students who have started learning Science and Mathematics in English will continue to do so until they complete their studies in Form Five.

Deputy Prime Minister Tan Sri Muhyiddin Yassin said the decision was made by the Cabinet to ease the concerns of parents.

This meant that pupils from Year Two onwards would continue learning under the Teaching and Learning of Science and Mathematics in English (PPSMI) policy, he said.

Muhyiddin and Deputy Education Minister Datuk Dr Wee Ka Siong talking to each other at the ministry staff briefing in Putrajaya yesterday. - Bernama

“I am not interested in the PPSMI debate and I hope parents understand that the Government is responsive.

“A circular on the issue has already been prepared and we will send it out to schools very soon,” he told reporters after briefing ministry staff on the “soft landing” of the policy.

Muhyiddin said schools would have the option to teach Science and Mathematics fully in English, Bahasa Malaysia, or bilingually.

“Students will continue with whatever system they have in place now, be it in English, Bahasa Malaysia or both languages.”

The two subjects will be fully taught again in Bahasa Malaysia starting 2016 for primary schools and 2021 for secondary schools.

Muhyiddin said research had shown that most schools were already teaching both subjects in Bahasa Malaysia.

“Less than 5% of 7,495 primary schools use English to teach the subjects, and for secondary schools, less than 9% out of 2,192 use English,” he said.

When pressed for more information, Muhyiddin said this meant that the medium of instruction for the two subjects in schools would be based on the needs of children and teachers.

“The schools would know better than me,” he said.

The PPSMI policy was initiated by former prime minister Tun Dr Mahathir Mohamad and implemented in phases, beginning with Year One, Form One and Lower Six students in 2003.

It was then announced in 2009 that the Government would reverse the policy and revert to Bahasa Malaysia in national schools, and Chinese and Tamil in vernacular schools, while more emphasis would be placed on English as a subject.

At the time, it was also announced that Form Six students would not be affected by the reversal so as to help them in their transition to tertiary studies.

Muhyiddin said public examinations for the two subjects would continue to be bilingual until 2016 for primary schools and 2021 for secondary schools.

“It is up to students to choose to answer in any language they are comfortable in.

“They can even answer one question in English and another in Bahasa Malaysia in the same examination paper,” he added.

Muhyiddin also said the ministry had produced textbooks in Bahasa Malaysia to cater to schools which were already teaching the two subjects in that language, as they had been using translations of the present English textbooks.

He added that the abolition of the PPSMI policy did not mean that the Government was ignoring the importance of mastering English.

“Under the policy on Upholding Bahasa Malaysia and Strengthening English, the ministry is implementing new initiatives to improve the mastery of English among students,” he said.

DPM to announce means for changeover to Malay

2011-10-31T01:27:00.002+08:00

Source: The Star, Saturday 29 October 2011, NATION (Page 12)
By KANG SOON CHEN
educate@thestar.com.my

PETALING JAYA: Deputy Prime Minister Tan Sri Muhyiddin Yassin will announce soon the mechanism for changeover to the teaching of Science and Mathematics in Bahasa Malaysia.

This is to ensure the smooth implementation of the revised policy, Deputy Education Minister Datuk Dr Wee Ka Siong said.

"What is important now is to prepare for the soft-landing approach so that students who had studied the subjects in English would not be affected by the change", he said after presenting prizes to student athletes at the MSSM-Milo Sports Awards ceremony here yesterday.

Muhyiddin, who is also Education Minister, had said Science and Mathematics would continue to be taught in both English and Malay up to 2015, when the final batch of students involved in the learning of Science and Mathematics in English (PPSMI) programme had completed their secondary education.

The PPSMI was implemented in phases from 2003, beginning with Year One, Form One and Lower Six students.

In 2009, Muhyiddin announced that the Government would revert to teaching the subjects in Bahasa Malaysia in national schools as well as Chinese and Tamil in vernacular schools.

Dr Wee said parents and groups who had lobbied for Science and Mathematics to be taught in English had the right to voice their views, adding that there were also groups which had opposing views.

"If the Cabinet does not change the decision made in 2009, the policy to revert to Malay in national schools and Chinese and Tamil in vernacular schools, will be carried out next year", Dr Wee said.

[Science Form 4] Energy Conversion

2011-10-13T03:00:00.004+08:00

Question:

How is electrical energy generated from nuclear energy?

Answer:

Nuclear energy is produced in a nuclear reactor.
The resultant heat energy is used to boil water.
Steam from the water rotates the turbines.
The turbine rotates and moves the dynamo.
The electricity generated is then directed to cables to be transmitted.

[Physics Form 5] Cathode Rays

2011-10-06T14:06:00.007+08:00

Question:
How are cathode rays formed?

Answer:

The 6V source first heats up the filament, which, in turn, heats up the cathode.
The cathode thus exhibits thermionic emission and produces thermal electrons.
The EHT exerts a strong electric field between the cathode and the anode, causing the thermal electrons to accelerate, and travel at a high speed and in a straight line towards the anode.
The beam of fast-moving electrons generated is known as cathode rays.

[Biology Form 5] Crossing Variants

2011-09-30T01:52:00.003+08:00

What happens when plants with different variants are crossed?

For example, when we cross a tall plant with a short plant, will we get all tall offspring, a mixture or only short ones?

The factor determining the outcome is the genotypes of the parents.

The genotype is the combination of a pair of alleles (or genes) that an individual has for a particular characteristic.

The phenotype refers to the physical aspect manifested by the combination of a particular set of genes in the DNA.

Example:
Two pure breed garden pea plants - one tall and one short - are crossed. What are the possible phenotypes and genotypes of their offspring? tall is dominant over short. [T: tall allele and t: short allele]

Solution:

[Biology Form 4] Gaseous Transfer

2011-09-29T02:10:00.003+08:00

What happens to the composition of atmospheric air when it reaches the alveoli?

Some of the oxygen dissolves in the film of moisture covering the epithelium of the alveoli.

From here, it diffuses into the blood in a nearby capillary, and enters a red blood cell before combining with the haemoglobin therein.

The diagram below shows the blood vessels involved in the transport of gases in the lungs.

Information: Organ/structure and its description

Bronchioles - The branched structures found at the end of each bronchus.
Trachea - A tube supported by C-shaped rings of cartilage.
Diaphragm - A dome-shaped sheet of muscle found at the bottom of the thorax.
Alveoli - If spread out, these structures would cover the size of a tennis court.
Ribs - The intercostal muscles are found between them.
Epiglottis - This is a special flap that covers the tracheal opening when we eat and prevents food from entering the trachea.
Bronchi - The two tubes found at the lower end of the trachea.
Nose - Air enters our body through this organ.
Pharynx - The passageway for air between the nose and the trachea.
Blood capillaries - The structures found on the outside of the alveoli.

[Science Form 1] Control Air Pollution

2011-08-04T01:27:00.001+08:00

There are many ways in which we can help prevent or control air pollution.

One of the ways is through saving energy!

How does saving energy help to reduce air pollution?

Well, power plants burn fossil fuels to produce gasoline, cooking gas, petrol and electricity.

So, whenever you use a lot of electricity, power plants will need to burn more fossil fuels.

This, in turn, will cause the release of more pollutants into the air.

Here's how you can help save energy.

Turn off the lights when you leave a room.
Replace energy hungry incandescent lights with fluorescent lighting.
Use a thermostat that automatically turns off the air-conditioner when you don't need it.
Use a fan instead of air-conditioning whenever possible.
Heat small meals in a microwave oven.
Don't use a water heater. Using cold water to bathe is refreshing and invigorating.
Dry your clothes on a clothes line.
Don't use a vacuum cleaner. Use broom instead.
Don't forget to switch off the television before going to bed.
Be sure to close the refrigerator door tight after you have opened it.

Now, did you know that a very large percentage of air pollution comes from vehicles, such as cars and buses? So, two important ways to reduce air pollution are to drive less and drive smart!

[Science Form 2] Eye On Defects

2011-05-27T16:49:00.010+08:00

A person with normal vision sees distant and close objects clearly. To maintain a clear image of the object on the retina, the thickness of one's eye lenses changes, in a process called accommodation.

However, for some people, clear vision is not achieved because of defects. Common vision defects are:

Short-sightedness (myopia)
Long-sightedness (hypermetropia or hyperopia)
Astigmatism
Colour-blindness
Lack of accommodation (presbyopia)

********************

1. Short-sightedness (Myopia)

People with myopia are not able to clearly see objects that are far away. This is because light rays focus in front of the retina, a result from the fact that eye is not able to focus light rays further back, despite maximum flattening of its lenses. Short-sightedness mainly affects a person's ability to look at distant objects where the light rays come straight (or parallel) into the eyes.

Short-sighted eye

Corrected short-sightedness

Short-sightedness is corrected by using glasses with concave lenses, which diverge light rays before they enter the eye.

2. Long-sightedness (Hypermetropia or Hyperopia)

People who are long-sighted can clearly see objects that are far away, but they have trouble seeing objects near them. If you are long-sighted, near objects may be so blurry that you cannot do tasks such as reading or sewing. Long-sightedness occurs when the eye does not bend light correctly. This causes the image of an object to focus behind the retina, instead of directly on it, thus resulting in a blurred image.

Long-sighted eye

Corrected long-sightedness

Long-sightedness is corrected by using glasses with convex lenses, which converge light rays.

3. Astigmatism

Astigmatism is caused by an irregular surface of the cornea, or a lense that is not evenly curved. As a result, the vertical and horizontal rays from the image cannot be focused at the same time. Both images may fall short of the retina, or one before the retina while the other behind it. Hence, terms such as compound hyperopic, compound myopic or mixed astigmatism. A person suffering from astigmatism may see certain parts of an object more clearly than others.

Astigmatic eye

Corrected astigmatism

Astigmatism can be corrected by either wearing glasses with cylindrical lenses, or surgery.

4. Colour-blindness

To understand what causes colour-blindness, you need to know about the cone cells or colour receptor cells in your eyes. These cone cells are on your retina, an area the size of a postage stamp that is at the back of your eye.

You have red, blue and green cones, which are sensitive to those colours and combinations of them. You need all three types to see colours accurately. When your cones do not work properly, or you do not have the right combination, your brain does not get the right message about which colours you are seeing. To someone who is colour-blind, a green leaf might look tan or grey. This defect cannot be corrected because it is hereditary.

5. Lack of Accommodation (Presbyopia)

The term presbyopia means "old eye" and and is a vision condition involving the loss of the eye's ability to focus on both near and far objects. It is a condition that occurs as part of normal aging, because when a person get older, one's eye lense becomes harder and less elastic. The muscles in the ciliary body also loss their ability to contract and relax. Presbyopia occurs gradually over a number of years and is usually noticeable by age 40-45.

Presbyopia is corrected by wearing glasses with bifocal lenses to see near and far objects clearly.

*******************

[Science Form 1] Animal Cells vs Plant Cells

2011-05-20T01:31:00.003+08:00

Cross-Section of Plant Cells

Differences between animal cells and plant cells.

DIFFERENCES

Animal Cells

Plant Cells

Size

Smaller in size.

Bigger in size.

Cell Shape

Do not have a fixed shape.

Have a fixed shape.

Cell Arrangement

Not arranged in a fixed pattern.

Arrange in a regular pattern.

Cell Wall

Do not have a cell wall.

Have a cell wall.

Vacuoles

Usually absent, but if present, vacuoles are small.

Have large vacuoles.

Chloroplasts

Do not have chloroplasts.

Green plants have chloroplasts to make food.

Food Storage

Store in the form of glycogen granules.

Store food in the form of starch grains.

Happy Mother's Day

2011-05-08T13:04:00.003+08:00

Wish you a Happy Mother's Day...

New Colour of Masjid UPM

2011-04-22T15:14:00.008+08:00

New looks of Universiti Putra Malaysia Mosque

2010 SPM results best in four years

2011-03-23T12:36:00.000+08:00

Source: The Star Online

PUTRAJAYA: Results for the 2010 SPM results are the best in four years, said Education director-general Datuk Abd Ghafar Mahmud.

He attributed this to the move last year allowing students to only sit for 10 subjects.

In a press conference called to announce the examination results on Wednesday, he said 9,239 candidates obtained distinctions, which was a combination of A+, A and A-.

This was higher compared to 7,987 candidates in 2009.

Abd Ghafar said 363 candidates obtained straight super distinctions of A+ in all subjects compared to 214 in 2009.

It had been announced in 2009 that students sitting for the SPM could take two additional subjects but the results would only be based on 10 subjects.

Subsequently, subjects including Chinese Language, Chinese Literature, Tamil Language, Tamil Literature and Arabic counted in the final grade if they fell within the maximum of 10 subjects that can be taken by students in the examination.

More >>

Explaining Fukushima Earthquake Nuclear Reactor Explosion (In Bahasa Melayu)

2011-03-23T02:39:00.005+08:00

Source: A video uploaded @ YouTube, by Mr. Azrudi Mustapha on Mar 13, 2011

Part 1

Part 2

Part 3

Notes by Mr. Azrudi Mustapha:

" I understand that the information in the public media is quite overwhelming to the majority who are concerned about this issue. This is my first attempt at explaining what actually goes on at the Fukushima nuclear plant right now, based only on what's available on the public media, as we don't really know what's really happening at the site. This is also an attempt to show you the source of the explosion and the issues surrounding the decisions that was made, but an important note is - It was not a nuclear detonation.

I have left out some bits and pieces during the making of the video, one of them is that the diesel generator DID work as designed after shutdown, but it worked only for about an hour, and then it is assumed that it got knocked down by a tsunami. I am sure they will investigate the cause once they're back on their feet. Thus, they were left with batteries to pump coolant to the plant - at its most critical moment when temperature rose. This is normal during reactor shutdown, heat will build up because fission product population does not decay quickly enough because of the lack of neutron sources. (Non operating reactor = no neutrons). It is important to note that the reactor has already shutdown, and they are trying to deal with residual heat which could cause a meltdown, but nowhere Chernobyl because Chernobyl melt down while operating. For this reactor, the residual heat will cool down naturally after reaching a peak point. Unfortunately, there is a lack of cooldown options at this peak point - and that is the main concern reactor operators were looking at.

It is unfortunate that this accident had to happen. Yes, it took a an 8.9 earthquake AND a tsunami to take out a 40 year old reactor that wasn't built with today's knowledge of material response to ground acceleration. Yes, they should have retrofitted all the updated engineering and equipment. Yes they should have added passive safety. Yes they should have had extra batteries. Yes they should have done many things. Yes the reactor was supposed to retire in 2 weeks. BUT, the public doesn't care. All the public cares about is radiation exposure. The public doesn't care that the radiation released is a lot lesser than the radiation coming out of chimneys of other types of fossil fuelled generating plants, or that it is much lower than the radiation produced from the processing and production of panels for TV and photo-capture. But it is not the public's fault, it is our fault that we have failed to develop public interest in science from the school, that we have not made science interesting enough, that we have not educated them well enough. We have failed at our second chance.

We remember the nuclear industry's philosophies : An accident anywhere IS AN ACCIDENT EVERYWHERE.

Yes, we hold ourselves to standards unparalleled by any other industry. For the first time in history, we have made it a requirement by Law and Regulations to notify the government for immediate evacuations when plant coolant fails - even though there is still a major chance of taking the plant back under control. Chernobyl wasn't evacuated at all. Three Mile Island wasn't evacuated - and the public stopped trusting the authorities. Today, the public was evacuated as a precaution, yet they still do not trust the authorities. But it is not their fault. Why didn't the plant get retrofitted with technology developed from the knowledge of the past 40 years after the plant was built? It is easy for the nuclear industry to blame it on the operators, but we only have ourselves to blame. If we do not blame ourselves, then we are hypocrites.

We could have done so much, but we didn't. The public gave us a second chance at a nuclear renaissance. But we blew it. Can't blame them.

Ironically, greenhouse effect gave the energies for disasters of this scale, but this disaster killed off one of the most strongest solutions we have against greenhouse effect and climate change. How's that for Food for Thought.

This video reflects my personal thoughts, and I don't claim to speak for any industry, any company, or any authority.

Azrudi Mustapha "

[Science Form 2] Air Pressure

2011-03-18T01:37:00.005+08:00

Since air has mass, the atmosphere pushes against all thing on Earth, including us! This "pressing down" of the atmosphere is called air pressure or atmospheric pressure.

Drinking through a straw

When you drink through a straw from an open glass of water, air pressure allow the water to travel up the straw. By sucking on the straw, you are reducing the air pressure inside your mouth.

While sucking in the straw, the air pressure in your mouth is less than the air pressure outside of the straw - in the room and in the glass. The outer air pressure pushes down on the water in the glass and this forces the water up the straw.

Can you predict what will happen if you put an airtight over the glass of water?

No matter how hard you suck, the water will not go up the straw. Why? Well, when air pressure on the water is blocked, there is no air pressure to help push the water up your straw. The air can't get to the water to push on it, so it doesn't go up the straw.

Unclogging the sink with a plunger

A plunger is made of a long stick and a bell-shaped, sturdy rubber cup on one end. The rubber cup of the plunger is set onto the draining hole of the sink to create a seal.

The plunger stick is then pushed down, inverting the rubber plunger cap and forcing the air that was in the plunger cap into the pipe.

The plunger is then pulled back, sucking air and water up with it, causing a vacuum. This abrupt force of air and water pressure helps loosen a clog in the pipes and gets the sink water draining again.

It may take several repeated motions of pushing and pulling back on the plunger to loosen the clog.

[Science Form 1] Fast facts on air pollution

2011-03-18T01:13:00.002+08:00

Emissions from ocean-going ships contribute to approximately 60,000 deaths each year, mostly from heart and lung-related cancers.
According to the World Health Organization (WHO), if you are one of the 18 million residents of Cairo, breathing air pollution daily is like smoking 20 cigarettes a day.
The World Health Organization (WHO) estimates that a billion premature deaths occur annually as a result of air pollution, half of which are people living in developing countries.
Children breathe at a faster rate than adults, and as a result, they breathe in much more polluted air than an adult.
If your home or school is located near a high traffic area, you have an increased risk for lung disease, bronchitis asthma and even cancer.

[Science Form 3] Generation of Electricity

2011-03-18T00:46:00.003+08:00

Generation of Electricity

Generator
Type;
- Thermal.
- Hydroelectric.
- Diesel.
- Nuclear.
- Gas turbine.
Transformer
Type;
- Step-up transformer.
- Step-down transformer.
Transmission and distribution
Consist of;
- National Grid Network.
- Switch zones.
- Transformer stations.
- Main substation.
- Substation branches.
Electricity supply
Type of wire;
- Life wire.
- Neutral wire.
- Earth wire.

Electrical Energy Generator

A device that is used to convert mechanical energy into electrical energy.
Induced current - When a moving wire or electrical conductor cuts across magnetic lines of force, electric current will be produced.
All electrical energy generators use the same principle of generation:
- The turbine is rotated.
- The turbine turns the dynamo that is connected to it. The dynamo has a wire coil placed in between a magnet.
- The wire coil cuts across the magnetic and electric current is produced.

Thermal Generator

Coal, petroleum or natural gas are burned in heat water in a boiler to produce steam.
Chemical energy --> Heat energy --> Kinetic energy --> Electrical energy

[Mathematic Form 1] Convert 24-hour system into the 12-hour system

2011-03-17T23:45:00.002+08:00

To convert the 24-hour system into the 12-hour system, follow the step below;

If the time is between 0000 hours and 0059 hours

You should...
- Add 12.00
- Add a dot between the hours and minutes
- Write am
  
  Example:
  - 0035 + 12.00 = 1235. So, 0035 = 12.35am
If the time is between 0100 hours and 1259 hours

You should...
- Remove the zero if necessary
- Add a dot between the hours and minutes
- Write am or pm
  
  Example:
  - 0530 = 5.30am
  - 1235 = 12.35pm
If the time is between 1300 hours and 2400 hours

You should...
- Subtract 1200 from it
- Add a dot between the hours and minutes
- Write pm
  
  Example:
  - 1428 - 1200 = 228. So, 1428 = 2.28pm
  - 2358 - 1200 = 1158. So, 2358 = 11.58pm

More Examples:

Convert each of the following into 24-hour system.
- 12.36am = 0036
- 3.45am = 0345
- 12.50pm = 1250
- 4.37pm = 1637
Convert each of the following into 12-hour system.
- 0048 = 12.48am
- 0539 = 5.39am
- 1255 = 12.55pm
- 1729 = 5.29pm

[Science] Proposal Kajian Tindakan 2011

2011-03-17T13:07:00.006+08:00

*********************

(Start Front Cover)

SEKOLAH MENENGAH KEBANGSAAN SERI INDAH
43300 SERI KEMBANGAN,
SELANGOR D.E.

PROPOSAL KAJIAN TINDAKAN 2011

Penyelidik:
NAZARIAH BINTI MOHD JAMANI

Tajuk Kajian:
Meningkatkan Kemahiran Murid Yang Lemah Memahami dan Mengingati Kedudukan Kelenjar Endokrin Dalam Tubuh Manusia Dengan Menggunakan Kaedah KELAWAR (KEnali meLAlui WARna)

(End Front Cover)
*********************
(Start Contents)

Nama Sekolah:
Sekolah Menengah Kebangsaan Seri Indah
Taman Seri Serdang, 43300 Seri Kembangan, Selangor D.E.
(Tel: 03-89434263, Fax: 03-89456695)
Penyelidik:
Nazariah binti Mohd Jamani
Tajuk Kajian:
Meningkatkan Kemahiran Murid Yang Lemah Memahami dan Mengingati Kedudukan Kelenjar Endokrin Dalam Tubuh Mmanusia Dengan Menggunakan Kaedah KELAWAR - KEnali meLAlui WARna
Refleksi Pengajaran & Pembelajaran Lalu:
Dalam sukatan pelajaran Science tingkatan 4, ‘The Endocrine System’ adalah salah satu sub topik yang seringkali disoal dalam peperiksaan. Namun, ramai pelajar yang lemah gagal menjawab dengan sempurna terutama sekali dalam melabel kelenjar endokrin.

Apabila saya cuba memikirkan apakah kaedah yang paling sesuai untuk digunakan oleh para pelajar dalam mengatasi masalah ini, saya terbaca satu artikel dalam sebuah blog yang menyatakan bahawa pelajar-pelajar yang lemah mudah tertarik kepada sesuatu yang berwarna warni atau dalam bentuk games. Antara masalah yang sering dihadapi pelajar dalam topik ini ialah:
- Melabel kelenjar endokrin dengan betul.
- Menyatakan hormon yang dirembeskan oleh kelenjar tersebut.
- Pelajar – pelajar tidak berminat untuk belajar kerana menganggap topik ini adalah sukar.
- Pelajar-pelajar memilih untuk tidak menjawab soalan berkaitan bab ini walaupun sebenarnya pelajar-pelajar berpeluang untuk memperolehi markah yang banyak sekiranya berjaya menjawab dengan betul.
- Pencapaian pelajar-pelajar dalam peperiksaan yang melibatkan topik kurang memuaskan.
- Guru mengajar berpusatkan guru.
Isu / Keprihatinan (Fokus Kajian):
Mata pelajaran SCIENCE adalah satu ilmu yang banyak memerlukan pemahaman dan penghayatan berbanding kaedah menghafal untuk mempelajarinya. Walau bagaimanapun kebanyakan pelajar menganggap setiap suatu proses atau konsep itu perlu dihafal terlebih dahulu tanpa perlu memahaminya. Ini menyebabkan ramai pelajar menghadapi masalah dalam mengingati keseluruhan konsep atau proses sesuatu topik.

Kaedah KELAWAR – Kenali meLAlui WARna adalah satu adalah satu teknik pembelajaran berpusatkan pelajar ( akses kendiri ) dimana guru memberi satu modul gambarajah suai padan berwarna tentang sistem endokrin dalam tubuh manusia.. Setelah mencuba modul tersebut secara perbincangan dalam kumpulan kecil, pelajar akan dapat lebih memahami dan seterusnya mudah untuk mengingati kedudukan system endokrin yang terdapat dalam tubuh manusia..
Objektif Kajian:
- Objektif Umum - Meningkatkan kemahiran murid memahami kedudukan kelenjar endokrin menggunakan kaedah KELAWAR.
- Objektif Khusus - Guru menggunakan kaedah KELAWAR untuk meningkatkan pencapaian 10% dalam Kertas 2 Science.
Kumpulan Sasaran:
Kajian ini melibatkan 10 orang pelajar kelas 4SPE2.
Tindakan Yang Dicadangkan:
- Tinjauan Awal Masalah.
  Sebelum langkah-langkah kajian selanjutnya dijalankan tinjauan terhadap masalah akan dikenalpasti terlebih dahulu bagi membantu pengkaji memahami masalah yang dihadapi pelajar. Tinjauan dilakukan menerusi langkah-langkah berikut:
  - Menjalankan ujian khas melibatkan soalan berstruktur iaitu melabel sistem endokrin dalam tubuh manusia untuk mengetahui tahap pemahaman pelajar dalam topik sistem endokrin.
- Menjalankan Kaedah KELAWAR – Kenali meLAlui WARna.
  
  Cara pelaksanaan:
  1. Pelajar diberi dengan set modul gambarajah suai padan berwarna tentang sistem endokrin dalam tubuh manusia.
  2. Modul tersebut terdiri daripada gambarajah system endokrin dalam tubuh manusia yang diwarnakan dengan warna yang berbeza-beza bagi setiap jenis kelenjar endokrin tersebut. Pemilihan warna juga adalah mengikut kesesuaian yang mudah diingati oleh pelajar iaitu:
    - Kelenjar Pituitary – Warna PUTIH
    - Kelenjar Thyroid – Warna HITAM
    - Kelenjar Pancreas – Warna HIJAU
    - Kelenjar Adrenal – Warna MERAH
    - Ovary - Warna MERAH JAMBU
    - Testis - Warna BIRU MUDA
  3. Pelajar meneliti gambarajah tersebut dan mengecam kedudukan setiap kelenjar endokrin berdasarkan warna.
  4. Pelajar menyelak petak-petak berwarna untuk mengetahui nama kelenjar-kelenjar endokrin tersebut.
  5. Masa yang diperuntukkan untuk Langkah c) dan d) adalah bergantung kepada tahap IQ pelajar masing-masing.
  6. Guru memberi set latihan melabel kelenjar endokrin kepada pelajar.
  7. Guru menganalisa latihan pelajar
  # Aktiviti ini akan diubahsuai jika berlaku keperluan berbuat demikian setelah membuat refleksi bagi aktiviti di atas.
Bahan Yang Dicadangkan:
- Modul KELAWAR – KEnali meLAlui WARna (The Endocrine system).
- Set latihan melabel kelenjar endokrin.
Jadual Pelaksanaan Kajian:
- Mengenalpasti masalah berdasarkan tahap pemahaman pelajar tingkatan 4 semasa tahun 2010 terhadap topik “The endocrine system” -> January 2011
- Menulis proposal kajian tindakan -> 7 March 2011
- Menjalankan pengajaran dan pembelajaran tentang tajuk “The Endocrine System” -> 17 - 18 February 2011
- Melaksanakan tindakan 1 – Tinjauan masalah ( 5.1a dan 5.1b) -> 24 – 25 February 2011
- Menganalisa dan merekod data hasil tindakan 1 -> 8 - 9 March 2011
- Melaksanakan tindakan 2 – Kaedah KELAWAR ( 5.2 ) -> 10 - 11 March 2011
- Menganalisa dan merekod data hasil tindakan 2 -> 17 - 18 Mac 2011
- Ujian untuk mengesan pencapaian murid (Peperiksaan Pertengahan Tahun) -> 17 May – 4 June 2011
- Refleksi kajian -> 7 – 8 June 2011
- Menulis laporan kajian tindakan -> 9 – 11 June 2011
Kos Kajian:
- Kertas A4 1 rim x RM 10.00 -> RM10.00
- Photostat bahan edaran 10 helai x RM 0.05 -> RM00.50
- Mencetak modul bahan edaran 10 set x RM 1.30 -> RM13.00
- Buku Catatan Guru -> N/A
# Jumlah Keseluruhan -> RM23.50
Penutup:
Penyelidik berharap agar kaedah KELAWAR ini akan lebih menarik minat pelajar terutamanya pelajar yang lemah untuk mememahami dan mengingati kedudukan kelenjar endokrin dalam tubuh manusia kerana kaedah ini bersifat permainan yang menyeronokkan dan akses kendiri.

(End Contents)

*********************

[Science Form 3] Functions of the heart

2011-03-10T03:55:00.002+08:00

Blood flows in a circulatory manner.
The heart pumps blood out through contraction and squeezing action.
- Blood is pumped out of the lungs to the heart through the pulmonary veins (oxygenated blood).
- Blood is pumped out to other body parts through the aorta.
- Arteries --> capillaries [ (dissolve oxygen + digested food + minerals --> cell)
  (waste products and carbon dioxide --> blood) ] --> veins.
- Veins carry deoxygenated blood back to the heart (right side).
- The deoxygenated blood is carried to the lungs to be oxygenated.

[Science Form 3] Blood vessels and their functions

2011-03-10T03:41:00.007+08:00

There are 3 types of blood vessels.

Arteries
Have a thick muscular walls to withstand high pressure.
Veins
The pressure in veins is usually low. Therefore, veins are wide and have thin walls with few muscles, which allow blood to flow more easily.
Capillaries
Capillaries, which have very thin walls, join veins and arteries. They transfer gases, food and excretory products between blood and body cell by diffusion through their thin walls.

[Mathematic Form 2] Stating & Plotting the coordinates of points

2011-03-10T02:11:00.003+08:00

ALWAYS remember:

When stating the coordinates of a point, the x-coordinate is always written first, followed by the y-coordinate.
The x-coordinate of all points on the y-axis is always zero.
The y-coordinate of all points on x-axis is zero.

(x, y)
x => x-coordinate (x units from the y-axis)
y => y-coordinate (y units from the x-axis)

Example:

Plot the following point on the graph given.

P (3, 4)
Q (-2, 0)
R (4, -1)
S (0, 2)
T (-3, -3)
U (-1, 4)

Answers:

[Science Form 3] Natural Fuel Resources

2011-03-10T00:37:00.006+08:00

Formed millions of years ago from dead organisms at the bottom of the sea.
Dead organism + Sedimen ---- (High temperature/Pressure) ---> Petroleum

Register your kids now!

2011-03-07T02:20:00.005+08:00

Source: Jabatan Pelajaran Selangor

Makluman Kepada Semua Ibu / Bapa / Penjaga (Negeri Selangor)

Applikasi permohonan Pendaftaran Murid Tahun 1 Sesi Persekolahan 2012 dan 2013 telah dibuka!

Untuk makluman, Pendaftaran Murid Tahun 1 Sesi 2012 dibuka sepanjang tahun ini, namun pendaftaran akan dikira lewat sekiranya dibuat selepas 30 APRIL 2011.

Pendaftaran Murid Tahun 1 Sesi 2013 dibuka sehingga 30 APRIL 2011 sahaja. Terima kasih.

Pendaftaran boleh dibuat secara ONLINE. Sila layari laman di bawah;

Gong Xi Fa Cai 2011

2011-02-03T01:42:00.007+08:00

Wishing You A Happy & Prosperous

Chinese New Year

GONG XI FA CAI

[Biology Form 4] How to Synthesis Extracellular Protein?

2011-01-16T11:48:00.005+08:00

Extracellular protein is the protein that is destined for export from a cell such as digestive enzyme that is made by pancreas cell.
The organelles that involved in the process are nucleus, ribosome, RER, Golgi apparatus and mitochondria.
Flow chart shows how the internal membrane system of a cell packages a protein for export.

1. Instructions for making protein are transcribed from DNA by RNA in the nucleus.

|
v

2. RNA leaves the nucleus through nuclear pore and proceeds to a ribosome located on the RER.
|
v

3. Ribosome synthesis the correct sequence of amino acids for synthesizing that particular protein as instructed.
|
v

4. When protein synthesis is complete, the protein travels through the RER and is then encapsulated in a transport vesicle.
|
v

5. The transport vesicle fuses with a Golgi apparatus, releasing the protein.

|
v

6. In the Golgi apparatus, the protein is further modified and is then shunted to the ends of Golgi apparatus or cisternae. There, the protein waits for a secretory vesicle.

|
v

7. The secretory vesicle will carry the protein to the plasma membrane of the cell and fuses with it. Then, the protein is released outside the cell.

SALARY 2011

2010-12-31T18:21:00.000+08:00

Schedule of Salary Payment (Government's Staff, Malaysia) for the Year 2011, as below;

1) January, 25th January 2011, Tuesday.

2) February, 24th February 2011, Thursday.

3) March, 24th March 2011, Thursday.

4) April 25th April 2011, Monday.

5) May, 24th May 2011, Tuesday.

6) June, 23rd June 2011, Thursday.

7) July, 25th July 2011, Monday.

8) August, 24th August 2011, Wednesday.

9) September, 22nd September 2011, Thursday.

10) October, 20th October 2011, Thursday.

11) November, 24th November 2011, Thursday.

12) December, 19th December 2011, Monday.

[Physics Form 4] Pascal's Principle

2010-09-30T01:52:00.008+08:00

Look at the following diagrams for a better understanding of Pascal's Principle.

Force Over Area

The symbols F and P represent force and pressure, respectively.

Observations:
When the force F is exerted on the lower pistons in all four diagrams, it generates a pressure of P₀ . The same pressure is generated on the upper pistons in diagrams I, II and III, but not in diagram IV.

In the diagram I and II, the force exerted by the upper pistons are equal to F, whereas in diagram III, the force is bigger than F, and in diagram IV, no force is exerted.

Based on the observations above, some conclusions can be made.

Conclusion (i):
Liquid X can transmit an equal magnitude of pressure from the lower piston to the upper piston. This abides by the Pascal's principle, which states that liquids are able to transmit pressure in equal magnitude in all directions. Air, with the exception of compressed air, however, is unable to transmit pressure.

Conclusion (ii):
Though the pressure generated is the same, the force exerted by the upper piston in diagram III is larger than F. This suggests that a larger surface area of an upper piston is able to multiply the force exerted by a lower piston. Hence, the force exerted is directly proportional to the surface area (the pressure generated on both pistons in diagram III is the same). This application is used in hydraulic brake and jack systems, in which their surface areas are increased to multiply the force exerted by the second piston.

Conclusion (iii):
Pressure on the first piston = pressure on the second piston.

F₁ /A₁ = F₂ /A₂

When the Pascal's principle is applied on a hydraulic lift, a force exerted on 'a' can lift a car at 'b'.

School-based assessment system may replace exams

2010-06-24T00:46:00.001+08:00

2010/06/23
NST

KUALA LUMPUR: A school-based assessment system may be used to replace an exam-oriented education system in the country, said Deputy Prime Minister Tan Sri Muhyiddin Yassin.

Muhyiddin, who is also Education Minister, said the Examination Board would determine the type of questions that can be used by teachers for such assessment in schools.

"We will replace exams with an assessment system. It has not been finalised but a study has been done and found to be acceptable because such a system is used in many countries.

"The system might not be very different from other countries, provided the education system - how teachers teach and how students study - is not affected. The concern is how to evaluate achievement of students - through examinations or assessment," he told the Dewan Rakyat when winding up debate on the 10th Malaysia Plan, for his ministry, here today.

He added that the government would not make hasty decisions on policy matters like proposals to scrap the Ujian Pencapaian Sekolah Rendah (UPSR) and Penilaian Menengah Rendah (PMR) exams.

"Many experts have said that it should have been done long ago, why now? We have carried out a research and study since 2007 because we have a team to look into such issues," he said.

Muhyiddin said reducing public examinations would actually save the government money in aspects of management, human resource and the burden of teachers to carry out such examinations process.

As for revamping technical, vocational and skills education system to become part of the premier education system of the country, Muhyiddin said the government would increase the number of vocational schools and introduce new curriculums to cater for growing demands.

"I myself am going to chair the meeting at ministry level to look at the main changes involved in the revamp of vocational, curriculum, infrastructure, facilities and training," he said.

He added that the Education Ministry would also take over the implementation of the Permata Negara programme from 2012.

The Permata programme, a model for the national childcare and early childhood education curriculum, is an effort by the government to educate children below the age of five and the system had been expanded to 457 centres nationwide, benefiting 17,565 children so far.

Meanwhile, Muhyiddin said overall RM26.093 billion was allocated to the Education Ministry as a whole, to carry out 15,324 projects, including an additional 808 projects under the Economic Stimulus Package.

"Until June 15, 8,870 project have been successfully completed, 5,312 projects are in various stages of implementation and 942 will be carried forward to 10MP," he said.

Muhyiddin said as of May 31, 2010 the ministry had spent RM16.668 billion or 85.12 per cent of the overall allocation. -- BERNAMA

[Biology Form 4] Program Bestari Fasa 2 - Cell Division

2010-06-17T02:47:00.008+08:00

The diagram shows a somatic cell during mitosis.
- a) State the mitotic phase in the diagram and give your reason.
  - Metaphase. Chromosomes are arranged at the equatorial plane.
- b) After the mitosis is completed,
  - i) how many daughter cells are produced?
    - 2.
  - ii) how many chromosomes are there in each daughter cell?
    - 4.
- c) Give an example of technology currently used which applies the mitotic process.
  - Cloning / tissue culture.
- d) Name 2 cells which do not undergo mitosis.
  - i) Nerve cell.
  - ii) Red blood cell.
The figure below shows the different stages of cell division in the mammalian ovary.

a) Using the letters in the diagram, arrange the stages of cell division in their correct sequence.
- G → F → A→ C→ E → B→ D
b)
i) Name the type of cell division illustrated in the figure above.
- Meiosis.
ii) With reference to the figure only, state two evidences to support your answer in [b) i].
- There are 2 cell divisions.
  - 4 daughter cells are formed.
  - bivalents are formed.
c) What biological term is used to describe the cells in stages D and G with respect to the number of chromosomes in their nucleus?
- D : haploid cell.
- G : diploid cell.
d) State one difference in appearance between the chromosomes in stage G and F and give your reason.
- Chromosomes in stage G appear as one stand but the chromosomes in stage F appear as two strands.
  - Reason: As the chromosomes in G continue to thicken, it is then seen as two sister chromatids in phase F.
The cell life cycle of an organism consists of phases X and Y. Phase X comprises of subphases P, Q and R. Phase Y comprises processes U dan V.

a)
i) Name process U.
- Mitosis.
ii) State the role of process U in living organisms.
- For the growth of organism.
- Replace worn-out tissue // for asexual reproduction.
b) Diagrams I, II, III and IV below show the stages in process U.

i) Arrange the stages of process U in the correct sequence below.
- IV → II → III→ I
ii) Name the stages in process U.
- I – Telophase.
  II – Metaphase.
  III – Anaphase.
  IV – Prophase.
c) What is phase X?
- Interphase.

[Biology Form 4] Program Bestari Fasa 2 - Chemical Composition Of The Cell

2010-06-16T18:21:00.008+08:00

General properties of enzymes.
- i) Enzymes are proteins produced by living cells.
- ii) Enzymes are biological catalysts which speed up the rate of biochemical reactions.
- iii) Enzymes are not destroyed at the end of a reaction.
- iv) Enzyme-controlled reaction is irreversible
  - Example : lactose + water , glucose + galactose
- v) Enzymes are sensitive to changes in temperature, and are very active at an optimum temperature of 40°C. Enzymes are denatured at high temperature .
- vi) Enzymes are sensitive to changes in pH of medium.
- vii) Enzyme action is very specific, One type of enzyme can catalyse only one type of substrate.

The figure represents the action of an enzyme.

a) State two properties of enzyme illustrated by the above figure.
- Enzymes action is very specific.
- Enzymes are not destroyed by the reaction they catalysed.
b) Name two digestive enzymes, their substrate and products.
- Enzyme : Amylase, Substrate : Starch, Products: Maltose.
- Enzyme : Trypsin, Substrate : Polypeptides, Products: dipeptides.
c) Figure below shows the relationship between enzyme activity and temperature. Complete the line to show the effect of increasing the temperature from 10°C to 60°C.

d) Uses of enzymes.

Enzymes	Usage types	Effect
Protease	Leather Industry	Remove hairs from skin
Papain//Protease	Digestion	Tenderise meat
Cellulase	Industrial use	Softening vegetables, removing seed coats
Protease//Lipase	Daily use	Add to washing powder to remove protein stains
Lipase	Digestion	Convert fat to fatty acids and glycerol
Amylase	Digestion	Convert starch to maltose

The figure shows an experiment set-up to investigate the effect of pH on enzyme activity. Enzyme Q is found inside the mammalian digestive system.
After 24 hours, the following results were obtained:

pH	Reduction in length of egg white strip (mm)
1	7
2	9
3	6
4	3
5	1
6	0

a) Using the results in the table, plot a graph to show the reduction in length of the egg white strip against pH of the medium.
- P – axis with scales ----1
- T – points plotted accurately ------ 1
- B – shape of line – smooth, single curve ------1
b) Explain the observed reduction in the length of the egg white strip.
- Increasing the pH value of the medium will decrease the action of enzyme Q on egg white. The optimum pH of enzyme Q is 2. Enzyme Q works at its maximum rate at this pH/ At this pH, the reduction of length of the egg white strip is the greatest.
c)
- Name enzyme Q and the products of its action on egg white.
  - Enzyme Q : Pepsin,
    Products: Polypeptides / Peptones
- Which part of the mammalian digestive system produce enzyme Q?
  Stomach.

Below shows the structures of four organic compounds which are found in living cells.
- a)
  - i) Name the structures of compounds X and Z.
    - X : Protein/ polypeptide.
      Y : triglyceride/ lipid.
  - ii) State the monomer of X and Y.
    - X : amino acid.
      Y : glucose.
- b) What would happen if pancreatic cells unable to synthesis compound X?
  - Enzymes / any pancreatic enzyme / hormones /any pancreatic hormone cannot be synthesised.
- c)
  - i) In the space below draw and label the structure of the basic unit of organic compound W.
  - ii) Name two types of organic compound W.
    - DNA & RNA.
  - iii) State two structural differences between the organic compounds you have named in (c)(ii).
    - DNA consists of two/double strands polynucleotide but RNA consists of a single / one strand of polynucleotide.
    - Strands of polynucleotide in DNA are twisted (around each other) / in a form of double helix but strand of polynucleotide in RNA is linear.
    * reject: molecules of DNA is big but molecules of RNA is small

[Science Form 4] The Endocrine System

2010-05-26T02:37:00.005+08:00

Insulin
- Convert glucose to glycogen.
Pituitary
- Found at the base of the brain.
Pancreas
- When the cells that produce insulin in one's pancreas are destroyed, he/she gets diabetes.
Testosterone
- Causes the development of men's secondary sex characteristics.
Glucagon
- Break down glycogen to release glucose.
Adrenal
- This gland secretes hormones when one is scared.
Ovary
- Controls the mentrual cycle.

In animal anatomy the endocrine system is a system of glands, each of which secretes a type of hormone into the bloodstream to regulate the body.

The endocrine system is an information signal system like the nervous system.

Hormones regulate many functions of an organism, including mood, growth and development, tissue function, and metabolism.

The field of study that deals with disorders of endocrine glands is endocrinology, a branch of internal medicine.

The endocrine system is made up of a series of ductless glands that produce chemicals called hormones.

A number of glands that signal each other in sequence is usually referred to as an axis, for example, the hypothalamic-pituitary-adrenal axis.

Typical endocrine glands are the pituitary, thyroid, and adrenal glands. Features of endocrine glands are, in general, their ductless nature, their vascularity, and usually the presence of intracellular vacuoles or granules storing their hormones.

In contrast, exocrine glands, such as salivary glands, sweat glands, and glands within the gastrointestinal tract, tend to be much less vascular and have ducts or a hollow lumen.

In addition to the specialised endocrine organs mentioned above, many other organs that are part of other body systems, such as the kidney, liver, heart and gonads, have secondary endocrine functions.

For example the kidney secretes endocrine hormones such as erythropoietin and renin.

10th International APICTA Awards Kuala Lumpur, Malaysia

2010-05-22T15:08:00.003+08:00

In conjunction with MSC Malaysia Summit 2010

ALL CAN PARTICIPATE
For more information and enter:
http://www.mscmalaysia.my/topic/APICTA

Happy Teacher's Day

2010-05-16T13:41:00.005+08:00

Teacher's Days are intended to be special days for the appreciation of teachers. Some of them are holidays while others are celebrated during working days.

World Teacher’s Day is celebrated across the world on 5th October, with great verve and enthusiasm.

Ever since the importance of teachers has been recognized by UNESCO, by adopting the “Recommendation concerning the status of teachers”, World Teacher’s Day has been celebrated annually.

This includes celebrations to honor the teachers for their special contribution in a particular field area or the community in general.

In some countries, World Teacher’s Day is celebrated by organizing conferences focused on the importance of teachers and learning.

In many countries, extra training sessions for teachers, recruitment drives for the teaching profession (among university students or other suitably qualified professionals) and events to increase the profile of teachers and the role they play in the media, are undertaken.

In Malaysia, 16 May was chosen as "Hari Guru" because on the same day in 1956, the Federal Legislative Council of the Federation of Malaya endorsed the Razak Report, one of four reports of the Education Committee regarding education in Malaysia.

The document, known as the Razak Report after Tun Abdul Razak who was Education Minister at the time, became the basis of education in Malaysia ever since.

Although it is not an official school holiday, celebrations are usually held on May 16, or earlier, if it falls on a Saturday or Sunday.

[Science PMR] Exam Pointers I

2010-05-12T03:14:00.007+08:00

A group of students carried out an experiment, using a spring and a set of slotted weights as shown in the diagram below, to investigate the relationship between the length of the spring and the weight.

Number of slotted weights	Extension of spring / cm
1	10
2	20
3	30
4	40
5	50

Table 1

State the variables that are involved in the experiment
- Manipulated variable => Number of slotted weights.
  Common error: Students only write "weights". You must write out the answer in full.
- Responding variable => Extension of the spring.
  Common error: Students only write "spring". You must write out the answer in full.
- Constant variable => The type of slotted weight/type of spring.
  Common error: "Retort stand" is not acceptable. The answer should be the variable that when changed will affect the reading.
Tutor's comment: Look at the table 1, the first column is the manipulated variable and the second column is the responding variable.
What is the aim of this experiment?
Answer: To investigate the relationship between the number of slotted weights and the extension of the spring.

Tutor's comment: It is to investigate the relationship between the manipulated variable and the responding variable.
What is the inference that you can make based on this experiment?
Answer: The extension of the spring depends on / is determined by the number of slotted weights.

Tutor's comment: The changes in the responding variable depends on the changes in the manipulated variable.
What is the relationship between the force applied to the spring and the extension of the spring?
Answer: When the force applied to the spring increases, the extension of the spring increases.
Based on the data, draw a graph to show the relationship between the length of the spring and the number of slotted weights.

Tutor's comment: Use a pencil when drawing the graph. If the question did not specify which type of graph to draw, draw a line graph.
Predict the length of the spring if 6 slotted weights are used.
Answer: 60cm

Tutor's comment: Draw the corresponding lines on your graph and get the reading from the graph.
What conclusion can be drawn from the experiment?
Answer: When the number of slotted weights increases, the extension of the spring also increases.

Tutor's comment: The conclusion will be the same as your hypothesis, that is "When the manipulated variable increase/decreases, the responding variable will increase/decrease."

[Chemistry Form 4] Forming Theories

2010-05-04T01:16:00.002+08:00

Man's first step in modern chemistry probably dated back to the discovery of fire. Thanks to it, man could cook food, make glass and also extract metals from ores.

Man was so content with the results of what they had done that they did not try to explain what had happened or why something had happened.

Only two thousand and five hundred years ago, philosophers began to question what things are made of, and what happens when things change.

The following is a brief history of chemists who had pondered about matter;

It was the 5th century BC in Greece. Empedocles suggested that all things on Earth are made from four fundamental substances he called elements. What were these four elements?
- Fire, water, air and earth.
Another Greek philosopher, born at the time Empedocles died, proposed that nature is made up of tiny particles he called atoms, which, in Greek, means indivisible. Who was this Greek philosopher?
- Democritus.
The atomic hypothesis was contested by the greatest philosopher at the time who remained faithful to the element theory. Because of his great reputation, the false element theory dominated scientific thought for two thousand years. Who was this famous Greek philosopher?
- Aristotle.
In later years, history has it that the Alexandrians were the first to devote themselves to alchemy, and they were soon followed by the Arabs, who introduced it into Western Europe. When was this?
- 4th century AD.
Chemistry then made little headway for years. In 1525, a Swiss doctor and scientist challenged his students to tear up their books, which recorded old theories that had been developed through reasoning, and told them to find out for themselves through experiments whether a scientific theory was right or wrong. This scientist had an imposing name. Who was this scientist?
- Theophrastus Bombastus Paracelsus Von Hohenheim.
Later on, Robert Boyle, an Englishman, succeeded in killing off the old idea of the four elements by establishing that there are other elements - substances that cannot be formed by or broken into other substances. When was this?
- 1661

A hundred years after Boyle made his discovery, a Swede, Karl Scheele, and an Englishman, Joseph Priestley, succeeded in isolating oxygen. Modern chemistry was thus born.

[Physics Form 4] Quantities Defined

2010-05-03T03:57:00.003+08:00

A physical quantity represents any property that can be measured by a scientific device and technique, and given a numerical value.

Classification of quantities

Physical quantities

Base quantities
- Base quantities cannot be expressed in terms of other physical quantities while derived quantities are combination of two or more base quantities.
- The five base quantities are current, length, mass, temperature and time.
Derived quantities
- Derived quantities result from the combination of base quantities through multiplication and divisive operations only.
- Mathematical operations like subtraction and addition are not involved.
  Eg: Work is a derived quantity because it is obtained through the combination of three base quantities - mass, length and time.
  
  Work = Force x Displacement
  Work = Mass x Acceleration x Displacement
  Work = (Mass x Velocity x Displacement) / Time
  Work = [Mass x (Displacement)²] / (Time)²
  
  Note: Displacement is measured in terms of length.
Scalar quantities
- Scalar quantities describe only the magnitude of physical quantities.
Vector quantities
- Vector quantities describe both the magnitude and direction of physical quantities.

[Biology Form 4] Being Multicellular

2010-04-27T02:32:00.005+08:00

A multicellular organism is made up of millions of cells, all of which carry out specific and different functions depending on their shapes and structures, and the organelles contained in them.

In multicellular organisms, cells make up tissues, tissues make up organs and organs make up systems.

In an entity, they cooperate with one another and ensure the organism carry out its seven main living processes.

The kind of organisation is extremely necessary to allow different systems to carry out specific functions and to enable the organism to be a complete and functional individual.

Cell organisation

To gauge whether you know how multicellular organisms from the plant and animal kingdoms are organised, as the following table.

Plant kingdom	Level of organisation	Animal kingdom
Hibiscus plant	Organism	Man
Shoot system	System	Circulatory system
Leaf	Organ	Skin
Vascular tissue	Tissue	Connective tissue
Mesophyll palisade cell	Cell	Epithelial cell

Another example of how two other multicellular organisms are organised.

Plant kingdom	Level of organisation	Animal kingdom
Maze	Organism	Rat
Root system	System	Circulatory system
Root	Organ	Lungs
Ground tissue	Tissue	Connective tissue
Parenchyma	Cell	Red blood cell

[Chemistry SPM] Exam Pointers I

2010-04-22T13:42:00.006+08:00

Essay
Shown (below) are the proton numbers of sodium and chlorine atoms.

Element: Sodium, Na
Proton Number: 11
Element: Chlorine, Cl
Proton Number: 17

a) The atomic radius of a chlorine atom is smaller than that of a sodium atom. Explain. [4_marks]

Answer: The electron arrangements of sodium, Na, and chlorine, Cl, are 2.8.1 and 2.8.7, respectively. Since both of them have three electron-filled shells, they are found in the third period of the periodic table. However, the positive charge in the nucleus of chlorine is higher than that of the sodium atom. This is because a chlorine atom has more protons than a sodium atom. This leads to a stronger force of attraction between the nucleus and the electrons of the chlorine atom. Hence, the shells filled with electrons are pulled nearer to the nucleus, thus reducing the atomic radius of the chlorine atom.

b) Chlorine reacts with sodium to form a compound.

i) Explain the formation of the compound. [6_marks]

Answer: The electron arrangements of sodium, Na, and chlorine, Cl, are 2.8.1 and 2.8.7, respectively. To form a sodium ion, a sodium atom donates one valence electron to achieve the stable octet electron arrangement, 2.8.
Na --> Na⁺ + e^-
To form a Cl^- ion, one atom of Cl receives one electron to achieve the stable octet electron arrangement, 2.8.8.
Cl + e^- --> Cl^-
The Na⁺ and Cl^- ions then forms an ionic bond as they are attracted to each other by a strong electrostatic force. Hence, an ionic compound of NaCl is formed.

ii) The compound conducts electricity is molten state but not in solid state. Explain. [2_marks]

Answer: In solid state, no free moving ions are available to conduct electricity since strong electrostatic forces hold the ions together. In molten state or aqueous solution, however, the charged ions can move freely to conduct electricity.

[Chemistry Form 4] Two-way Conversion

2010-04-21T03:10:00.002+08:00

Electrochemistry is the science that studies the relation between electricity and chemical changes. So how are they related?

An electric current can bring about an otherwise non-spontaneous chemical reaction, such as the recovery of metals from their ores and electroplating of surfaces.

In the process called electrolysis, electrical energy is converted into chemical energy, which is stored in the products of the reaction.

Aluminium and copper are some examples of the products of electrolysis.

Conversely, chemical energy can be converted into electrical energy.

This process can be seen in spontaneous chemical reactions and forms the basis for batteries and fuel cells in supplying electrical power.

An electrolyte is an electrically conductive substance that contains positively- and negatively- charged particles called ions.

The following are electrolytes and non-electrolytes;

Electrolytes
1. Copper (II) chloride
2. Molten aluminium oxide
3. Sodium hydroxide solution
4. Silver nitrate solution
Non-electrolytes
1. Aqueous ammonia
2. Copper (II) sulphate crystal
3. Glucose solution
4. Ethanol
5. Solid sodium chloride
6. Molten naphthalene
7. Acetamide
8. Tetrachloromethane

Did You Know?

A battery is a device that converts chemical energy into electrical energy. In 1800, Italian physicist Alessandro Volta developed the first electric battery that generated a steady stream of electricity. His invention was called the Voltaic pile.

Since then, the principles applied to the Voltaic pile have been used in batteries. In 1881, the volt (V), an electrical unit, was named after him.

[Science Form 1] Uses of Carbon Dioxide

2010-04-16T00:57:00.002+08:00

Carbon dioxide is used in many consumer products that require pressurized gas because it is inexpensive an nonflammable.

Liquid and solid carbon dioxide are important refrigerants, especially in the food industry, where they are employed during the transportation and storage of ice cream and other frozen foods.

Solid carbon dioxide is called "dry ice" and is used for small shipments where refrigeration equipment is not practical.

Carbon dioxide is also used in the drinks and food that we consume everyday.

Activity

Can you name a few types of food that contain carbon dioxide?

[Science Form 3] Electricity

2010-04-07T03:30:00.004+08:00

Electrical energy

Definition: Energy produced when an electric current flows.
The source of electrical energy is any device that produces electric charges or electric current.

Electricity

Definition: The flow of electric charges through a conductor.
Electrons flow in the direction opposite to the electric current. The electric current is the rate of flow of electric charges passing through a conductor.
The unit of electric current (I) is ampere.
The unit of voltage (V) is volt.
The unit of resistance (R) is ohm.
Different materials have different resistance to electricity.
The resistance of a conductor is affected by its length, diameter and temperature.
A very high resistance allows only a very small amount of current to flow.

Van De Graaff generator

The Van De Graaff generator is a device that can produce electric charges of very high voltage. When the motor is turned on, the lower roller (charger) begin turning the belt.

As the belt is made of rubber and the lower roller is covered in silicon tape, the lower roller will begin to build a negative charge while the belt builds a positive charge.

The negative charge on the lower roller is built up by capturing electrons from the belt as it passes over the roller. This occurs as silicon is more negative than rubber in the triboelectric series.

[Science PMR] Exam Overview

2010-04-05T20:38:00.003+08:00

The PMR science exam consists of two papers:

Paper 1 (40 marks)

40 objective questions.
One hour to complete the paper.
Cover all 27 Science topics from Form One to Form Three.
There will be at least one question from each topic.
The questions are broken down into:
- 50% easy questions; that is about 20 questions.
- 30% moderate questions; that is about 12 questions.
- 20% difficult question; that is about eight questions.

Paper 2 (60 marks)

Section A consists of six questions for 40 marks.
Section B consists of two questions for 20 marks.
Only questions from selected topics will be asked.
Answers can be written all in English or all in Bahasa Melayu or a combination of both language [Please do not combine both languages in the same sentence!]
You may answer part of the question in one language and the other part in the other language.
The questions are broken down into:
- 50% easy questions; that is about 30 marks.
- 30% moderate questions; that is about 18 marks.
- 20% difficult questions; that is about 12 marks.
The type of questions commonly asked in Paper 2 are:
- Labelling questions
- Classification
- Questions based on experiments
- Chemical tests
- Calculation
- Principles of science
- Drawing
- Structured questions
- General questions

[Science Form 3] Units of Electricity

2010-04-05T00:27:00.004+08:00

Volts (V)

Voltage can be compared to the pressure of water in a hose. The higher the pressure, the faster the water will flow through the hose.

Similarly, the higher the voltage of electricity, the faster it will flow from the source of the electricity to an end user.

A volt, or the unit of voltage, is a common electrical measurement. It is used, for example, to discuss the transmission of electricity from power plants to end users.

Ohms

Ohm measure resistance and can be compared to the diameter measurement of a hose. A smaller diameter hose will allow less water to flow through than a larger diameter hose.

Similarly, a thinner wire increases resistance, causing a lesser amount of electricity to be transmitted because it is encountering resistance in the wire.

To reduce resistance, certain metals, such as copper, which allows electrons to flow easily, are used to conduct electricity.

Amperes (A)

Amperes can be compared to the volume of water that flows through a hose. The volume of water that flows past a certain point in a specific amount of time can be measured.

Similarly, amperes measure the number of electrons that pass a specific point within a certain amount of time (rate of current) in a circuit.

One ampere is equivalent to approximately 6.25 X 10¹⁸ electrons passing by a specific point in one second.

The rate of the electric current is dependent upon the voltage and resistance. A circuit with high voltage and low resistance will have more amperes (greater number of electrons passing through the circuit) than a circuit with low voltage and higher resistance. The former example has more power than the latter.

It is important to measure the amount of amperes in a circuit because it can help calculate the amount of power consumption or output of a circuit.

Ohm's Law

Ohm's Law is used to describe the mathematical relationship between electric current, voltage and resistance.
We can arrange Ohm's Law depending on which component we are trying to find out.
- I = V/R
- V = I x R
- R = V/I
All these variations of Ohm's Law are mathematically equal to one another...
Measuring of;
- Current (I)
  - Method: Ammeter
    Unit= Amperes (A)
    # The ammeter is connected in series to a circuit. The movement of the ammeter needle shows that current is flowing in the circuit.
- Voltage (V)
  - Method: Voltmeter
    Unit: Volts (V)
    # The voltmeter is connected in parallel to a circuit when measuring voltage.
- Resistance
  - Method: Resistor
    Unit: Ohm
    # The higher the resistance, the bigger the ohm value in a resistor.

[Science PMR] The Experiment Question

2010-04-02T02:43:00.003+08:00

The last question in Paper 2 is usually question number 8, which carries 12 marks. This question will be based on an experiment where you have to write down:

Readings [Make sure the unit of measurement you use is correct]
Variables
- Constant variable [This is the fixed variable]
- Manipulated variable [This is the factor that is changed in the experiment to get the specific result. ie: Length of wire (cm)]
- Responding variable [This comes from the readings or the results of the experiment. ie: Ammeter reading]
Aim of experiment
- Example: To study/investigate the relationship between the manipulated and the responding variable.
Hypothesis
- This shows the relationship between the manipulated and the responding variable.
- Writing format: "When the manipulated variable increases/decreases, the responding variable will increase/decrease."
Observation
- What can be observed or what you can see.
Plot a line or bar chart
Prediction
- This will be based on your graph, where you have to predict a reading for the responding variable when given a value for the manipulated variable.
- Example of a question: From the graph, find out the value of T when the mass is 10g.
Inference
- This is the early conclusion based on your observations.
- Example: The change in the responding variable depends on the manipulated variable.
Conclusion
This is the same as the hypothesis.

Note: It is very important to get your manipulated variable and the responding variable correct!

[Biology Form 5] Meeting Gametes

2010-03-29T02:15:00.003+08:00

Study the following details for a better understanding of gametogenesis and what happens after it.

Process and location
- Male - Spermatogenesis in the testes.
- Female - Oogenesis in the ovaries.
Parent cell for gametogenesis
- Male - Primary spermatocyte.
- Female - Primary oocyte.
Cell produced after Meiosis I
- Male - Two secondary spermatocytes.
- Female - One secondary oocyte (X) and one (1st) polar body (Y).
Cell produced after Meiosis II
- Male - Four spermatids.
- Female -
  - From the secondary oocyte (X): One ovum + One polar body.
  - From the first polar body (Y): Two other polar bodies.
What happens to cells produced after Meiosis II?
- Male - Spermatids differentiate into sperms.
- Female - All three polar bodies will degenerate; only the ovum will survive.
When does Meiosis II occur?
- Male - Immediately after Meiosis I.
- Female -
  - For the first polar body: immediately after Meiosis I.
  - For the second oocyte: only after a sperm penetrates the oocyte.
What happens during sexual intercourse?
- Male - Sperms are ejaculated from a male's penis into a female's vagina.
- Female - Sperm from a male swim upwards, from a female's vagina, through the cervix, into the uterus and then to the Fallopian tubes.
Site for fertilisation
- Male - none.
- Female - In the Fallopian tubes of the female reproductive system.
Product of fertilisation
- Male - none.
- Female - A diploid zygote (containing 46 chromosomes), which then develops into an embryo.

What happens after sexual intercourse?

Possibility I
- A sperm meets the secondary oocyte and penetrates it.
- Meiosis II quickly occurs in the secondary oocyte, and an ovum and a polar body is formed.
- The polar body degenerates.
- The nucleus of the ovum fuses with the nucleus of the sperm.
- Fertilisation is successful and a diploid zygote is formed.
- The female is pregnant.
Possibility II
- None of the sperms meet the secondary oocyte. This could mean ovulation has
  - not occurred yet;
  - occurred but the secondary oocyte, which can only live for 24 hours, has died.
- No fertilisation occurs.
- No zygote is formed.
- The female is not pregnant; she gets her next period as usual.

[Biology Form 4] Movement Across The Plasma Membrane

2010-03-25T01:23:00.014+08:00

1. Three types of passive transport.

Simple diffusion
Osmosis
Facilitated diffusion

2. TRANSPORT

Active Transport
Passive Transport
- Simple Diffusion: The movement of molecules from region of high concentration to low concentration.
- The movement of molecules from region of high concentration to a region of low concentration with the help of carrier proteins.
- Osmosis: The movement of water molecules from dilute solution to a concentrated solution across a Semi permeable membrane.

3. The figure below shows the model of the plasma membrane. Label L, M, N, and O shows four types of nutrients. P1, P2 and P3 show three types of protein.

(i) Name the processes labelled L, M, N, O.
L : Simple diffusion
M : Fasilitated diffusion
N : Fasilitated diffusion
O : Active transport

(ii) Name the protein labelled P1, P2 and P3.
P1 : Pore protein
P2 : Carrier protein
P3 : Carrier protein

(iii) State two characteristics of the molecules that are transported into the cell by process L.
1. Small
2. Soluble in lipid

4. The figure shows a model of the active transport system that depends on several carrier proteins found in the cell membrane.

(i) Explain what do you understand by active transport.
Movement of particles across the plasma membrane

by carrier proteins,
against the concentration gradient and
requires energy.

(ii) Give an example of active transport in plants.
Ion or mineral uptake by plant root hairs.

(iii) State two differences between active transport and diffusion.
Any two differences – energy, gradient concentration, living membrane.

5. The table below shows the effect of hypotonic, isotonic and hypertonic solution on spinach strips, red blood cells and plant cells.

Hypotonic solution

Isotonic solution

Hypertonic solution

Spinach strip in distill water

· Distill water is hypotonic compared to the cell sap.

· Water enters into spinach cell through cut surface by osmosis . Epidermis is water proof.

· The epidermis layer curved inward.

Spinach strip in 5% sucrose solution

· The rate of water entering and leaving the spinach cell through semi permeable mambrane

is the same.

· The shape of spinach strip remains the same

Spinach strip in 30% sucrose solution

Red blood cell in distill water.

Red blood cell in isotonic solution

Red blood in 30% sodium chloride solution

Plant cell in distill water

Plant cell in isotonic solution

Plant cells in 30% sucrose solution

[Biology Form 4] Cell Structure & Organisation

2010-03-24T22:15:00.006+08:00

1. Study the diagrams below. Identify the structures or organelles (A – J) and complete the following table.

	Name of organelle / structure	Function	Consequence if absent
A	Rough endoplasmic reticulum	Transporting proteins	No transportation of proteins
B	Mitochondrion	Site for energy production	Energy cannot be produced
C	Cell wall	Give fixed shape to the cell	Have irregular shape (eg. Animal cell)
D	Smooth endoplasmic reticulum	Transport lipid and glyserol	Lipid and glycerol cannot be transport
E	Nucleus	Control cell activities, contains genetic material.	No cell division, all cell activities stop.
F	Vacuole	Storing nutrients (sugar and amino acid) in its sap.	Cannot store nutrients
G	Cytoplasm	Food storage, medium for metabolic reaction	No site for metabolic reaction
H	Plasma membrane	Controlling entry and exit of substances	No selective barrier
I	Lysosomes	Releases enzymes outside the cell.	No enzymes being released
J	Chloroplast	Carries out photosynthesis	Photosynthesis cannot occur
	Golgi apparatus	Storing and transporting lipids. Produces glycoprotein, polysaccharide and secretory enzyme.

2. Give two differences between animal and plant cell
Any two differences: Cell wall, Vacuole, Centriole, Storage granule, Chloroplast

3.
a) What is cell specialization?
Cell changes in structure or function in order to carry out a specific function.

b) How are cells organised into a multicellular organism?
Cell --> Tissue --> Organ --> System --> Organism

c) Give an example of each type of cell organization in human.
Epithelium Cell --> Epithelium Tissue --> Stomach --> Digestive System --> Human

[Biology Form 4] Plant & Growth

2010-03-24T08:38:00.007+08:00

Name the phase in which the:
a) centromeres of chromosomes are lined up at an imaginary plane across the middle of the cell
- Metaphase
b) nucleolus re-forms and the spindle fibres disappear
- Telophase
c) chromosomes are visible as duplicated, thick and short thread-like structures
- Prophase
d) cell is about ready to divide by cytokinesis
- Telophase
e) cell is gathering its energy to begin active mitosis
- Interphase
f) two sister chromatids of each chromosome separate at the centromere
- Anaphase
Based on the diagram, answer the following questions:

a) Name the tissue found at the tip of a plant root.
- Apical meristem
b) Where else in a plant is this tissue usually found?
- Shoot tip
c) State the characteristics of the cells found in the tissue named in (a).
- Very small in size / isodiametric in shape /contain a dense cytoplasm / have a large nucleus
d) When mitosis occurs in these cells, primary growth, which records an increase in length and height, results in the root and shoot.

e) For secondary growth in a plant, mitosis occurs in the vascular cambium, a tissue found between the xylem and phloem tissue in dicotyledons.

f) Mitosis is important for growth because it increases the number of cells in the organism.

[Science Form 5] Hydraulic Jack

2010-03-14T03:28:00.006+08:00

Operation of a hydraulic jack

The hydraulic jack work on a system of valves,pistons and reservoirs. When the small piston is lifted, liquid rushes in from the reservoir through the open valve P. In the meantime, valve Q is closed. The cylinder connected to the small piston is filled with fluid.

When the small piston is pressed downwards, the pressure produced is transferred onto the liquid to the big piston. At the same time, valve P closes and valve Q opens.

A huge force is created depending on the area of the big piston. The, the lift on the big piston exerted is locked in position.

With another lift from the small piston, the big piston is lifted higher and higher until the desired height is reached. The tyre can then be changed. Work on the undercarriage of the car can also be carried out.

[Chemistry Form 4] Ions In Solution

2010-03-13T23:52:00.003+08:00

Swedish chemist Arrhenius defined acids as substances that, when dissolved in water, produce hydrogen ions (H⁺). Eg: When gaseous hydrogen chloride reacts with water, the amount of hydrogen ions in the water increases and hydrochloric acid is thus produced.

HCl (g) ---> H⁺ (aq) + Cl^- (aq)
Acid
(H⁺ producer)

Some of the food and medicines that we take contain acids. Ethanoic (acetic) acid in vinegar and acetylsalicyclic acid in aspirin, for instance.

Contrary to acids, bases are defined as substances that, when dissolved in water, yield hydroxide ions (OH^-). Eg: When sodium hydroxide dissolves in water, the amount of hydroxide ions in the water increases and the alkaline solution is thus produced.

NaOH (s) ---> Na⁺ (aq) + OH^- (aq)
Base
(OH^- producer)

Did You Know?
The compounds responsible for colours in plants are often sensitive to acids and alkalis. For example, blue hydrangeas grow only in acidic soils; in neutral or alkaline soils, they turn to pink.

[Science Form 5] Forceful Fluidity

2010-03-13T23:17:00.003+08:00

When a force is applied onto a liquid, the pressure created in the liquid acts in all directions. This is because when liquid is at a standstill, matter in the liquid is distributed evenly, and because of this, pressure is also distributed throughout equally. This property of liquid is captured in the hydraulic principle, which is used widely in hydraulic jacks and hydraulic brakes. The principle is based on the formula: F₁/A₁ = F₂/A₂

A small force F₁ applied on area A₁ is transferred onto a liquid and then onto on an area A₂, which subsequently produces a huge force F₂.

Note: The larger the area, the larger the force is, and thus, a greater weight can be supported.

Eg: A force of 2N is applied on area of 1m². If the area on the other end is 10m², what is the force generated at the same end?
10 times more, which is 2N x 10 = 20N

Also, pressure in liquid is seen as energy per unit volume (using the definition of work). The relationship can be easily explained by the Bernoulli's Equation.

P = Force/Area = F/A = (F x d)/(A x d) = W/V = Energy/Volume

7,987 SPM Candidates Excel

2010-03-11T22:02:00.002+08:00

NST
2010/03/11

PUTRAJAYA: 7,987 Sijil Pelajaran Malaysia (SPM) 2009 candidates registered excellent results (A+, A, and/or A-) for all subjects sat for compared to 6,277 in 2008.

Education director-general Tan Sri Alimuddin Mohd Dom said of the total 214 candidates had excellent grades (A+) in accordance with the new grading implemented last year.

He said the new top grade was introduced as a higher grade than 1A to further detail a candidate's excellence.

"I am glad to announce that on the whole the achievements of the candidates this time is something to be proud of, exceeding the achievements of last year.

"The achievements of the candidates increased from the aspect of numbers obtaining excellent certificates (A+, A and/or A-) and passing all subjects sat for," he said when announcing the analyses for the SPM and Sijil Tinggi Agama Malaysia (STAM) 2009 examinations at the Education Ministry here today.

He said 465,853 candidates registered for exams last year.

Alimuddin said of the 59,433 private candidates and candidates of private schoolS and agency-sponsored schools besides the Education Ministry, 41 candidates had excellent grades (A+).

He also announced that Gladys Tan Yee Kim from Sekolah Menengah Kebangsaan (SMK) Green Road, Kuching, Sarawak was the best student for SPM 2009 and Sekolah Menengah Sains Seremban, Negeri Sembilan as the best school.

He said of the 10 best students the other nine were Grace Kiew Sze-Ern (SMK (P) Sri Aman, Petaling Jaya, Selangor); Khadijah Ahmad Jais (SM Agama Persekutuan Labu, Negeri Sembilan); Akmal Hidayat Sabri (SMK Derma, Kangar, Perlis); Syamilah Mahali (Kolej Tunku Kurshiah Seremban, Negeri Sembilan); Lee Wei Ling (SMK Taman Melawati, Selangor); Nur Syuhadah Muhamad (SM Sains Tengku Muhammad Faris Petra, Kota Bharu, Kelantan); Lai Yin Kwin (SMK Tinggi Melaka, Melaka); Corinne Gunn Huey Min (SMK Taman Melawati, Selangor); and Hu May Khei (SMK Convent, Taiping, Perak).

He said the other nine best schools were Kolej Islam Sultan Alam Shah, Klang, Selangor; Sekolah Berasrama Penuh Integrasi (SBPI) Gombak, Jalan Sungai Pusu, Gombak, Kuala Lumpur; Sekolah Tun Fatimah, Johor Bahru, Johor; Sekolah Menengah Sains Alam Shah, Kuala Lumpur; SBPI Rawang, Selangor; Sekolah Menengah Sains Muar, Johor; SBPI Temerloh, Pahang; SMK Infant Jesus Convent, Johor Bahru, Johor and Kolej Tunku Kurshiah Seremban, Negeri Sembilan.

Alimuddin said of the 406,420 Education Ministry candidates who sat for the exam, 364,046 (90.8 per cent) obtained the SPM certificate compared to 347,443 (90.8 per cent) in 2008.

"Eventhough the percentage is the same there has been an increase in the number of candidates of 16,603. The achievement is stable as the previous year.

He said 199,155 (49.6 per cent) candidates passed all subjects taken compared to 181,419 (47.4 per cent) last year.

He said of that total 68,131 (17 per cent) had at least grade C for all subjects compared to 60,902 (15.9 per cent) in 2008.

"This achievement shows a good increase. However, the number of candidates who failed or obtained G grade increased, that is 4,626 (1.15 per cent) in 2009 compared to 2,589 (0.67 per cent) in 2008," he said.

Alimuddin said 538 candidates who had special needs for various disabilities sat for the 2009 SPM exam compared to 481 candidates in 2008 and of that number 251 (51.9 per cebt) obtained the SPM certificate compared to 208 (47.8 per cent) in 2008.

He said two candidates with impaired eyesight got four A+, three As and four A- for 11 subjects sat for and one had four A+, three As and three A- for 10 subjects sat for.

"Two more candidates with various handicaps did very well when both got eight A+, two As for 10 subjects taken," he said.

He said the achievements of urban and rural students was better compared to the previous year as 5,942 urban students and 1,243 rural students did well in all subjects compared to 4,750 urban students and 989 rural students in 2008.

He said the divide between urban and rural students was narrowed in performance in core subjects like English, Science and Moral Education.

Alimuddin said however efforts to reduce the performance divide between urban and rural students needed to be increased especially in Bahasa Melayu, History, Mathematics and Islamic Studies.

He said based on average school grades, 66 schools were in the Excellent category, 278 (Good), 1,654 (Satisfactory) and 143 (Potential) and this showed that the efforts of the ministry to enhance schools' performance was successfully implemented.

Alimuddin said the number of students who passed the Bahasa Melayu and English language papers in the SPM exam last year charted an increase compared to the previous year.

He said 364,046 students passed Bahasa Melayu in last year's exam compared to 347,443 in 2008 and 302,501 passed English compared to 282,471 the previous year.

He said the government was striving towards entrenching Bahasa Melayu and strengthening English so that the performance in both these subjects can be enhanced.

In JOHOR BAHARU, 1,010 candidates obtained excellent grades(A+, A and/or A-) in all subjects sat for including 29 who had A+ for all subjects sat for.

State education director Sufa'at Tumin said 39 schools had 100 per cent passes while the state average grade was 5.32.

"Overall, the Johor SPM results are something to be proud of. 42,370 candidates got the SPM certificate compared to 40,379 in the previous year," he said.

Sufa'at said 23,625 candidates passed all subjects taken and of that number 8,173 had at least a C grade in all subjects taken.

He said Sekolah Menengah Kebangsaan Infant Jesus Convent, Johor Baharu, student Tan Yen Ling, was the best student with 14A+s.

In ALOR SETAR, Kedah education director Shahidan Abd Rahman said the SPM results in the state showed an average grade of 5.560.

"Among schools that registered excellent results were SBPI Kubang Pasu, SMK Sultanah Asma, SM Sultan Abdul Halim, SMK Sultan Badlishah, SM Sains Pokok Sena, SM Sains Sultan Mohamad Jiwa, SMK Ibrahim, SMK Keat Hwa and SMK Agama Sik," he said in a media statement here today.

Shahidan said nine candidates got A+ in all subjects taken while 408 (1.33 per cent) had A+, A and A- in all subjects sat for.

In SEREMBAN, Deputy state education director Jamali Salam said 15 candidates had A+ in all subjects. They were among 590 candidates who were excellent students with A+, A and A- in all subjects taken.

"Felda schools showed good performance. There were four excellent students as opposed to none the previous year," he said.

In KUALA LUMPUR, 669 candidates had excellent grades of A+, A and A- with 21 having A+ in all subjects taken.

Kuala Lumpur education director Mohd Adenan Deraman said the results were good as 17,681 candidates earned the SPM certificate compared to 16,789 the previous year.

Four schools registered excellent results and they were Sekolah Menengah (SM) Alam Shah, Sekolah Menengah Sains Seri Puteri, Sekolah Menengah Kebangsaan Aminuddin Baki and SM Sains Selangor.

In PENANG, state education director Ibrahim Ahmad said 26 students had A+ while 717 had a combination of A+, A and A- in all subjects taken.

"The achievements of fully government aided schools is good and 17,373 candidates out of 20,042 or 87.71 per cent will receive the SPM certificate.

Ibrahim said 20 schools in the state registered 100 per cent passes and among them were SMK (P) St George, SMKA Al-Irshad, SMK Dato Onn, SMK Penang Free and SMK Bukit Jambul.

In KANGAR, state education director Mansor Lat said the results were better this time where 4,255 candidates out of 4,696 will get the SPM certificate.

Seven candidates got A+ in all subjects taken while seven schools registered 100 per cent passes compared to six last year.

[Physics Form 5] Power Of Resonance

2010-03-10T20:53:00.005+08:00

Resonance is what happens when the vibrations produced by one object come into alignment with those another. An apparatus set-up is shown as below.

When the radio is switched on, the diaphragm is observed to vibrate. A few moments later, the polystyrene ball starts to oscillate. It oscillates as long as the radio switched on. When the radio is switched off, the amplitude of oscillating polystyrene ball decreases and eventually becomes zero.

Q & A

Q: How is the polystyrene ball able to oscillate when no apparent external force is present to displace and release it?
A: The vibration of the loudspeaker produces energy, which is transferred to the air molecules in front of it. The energy is then transferred from one air molecule to another until it reaches the polystyrene ball. When the polystyrene ball receives the energy, it is displaced from its equilibrium position, thus setting it into oscillation. This shows that the oscillating system transfers its energy to its surrounding medium.
Q: Why is a polystyrene ball used? What if the polystyrene ball is substituted with a lead bob?
A: Polystyrene is lighter or less massive than most materials. If a lead bob is used, no oscillation will be observed. A lead bob, with a relatively larger mass, generates larger inertia. Hence, the small amount of energy transferred by the loudspeaker is not able to overcome the inertia and displace the bob to set it into oscillation.

Did You Know?

The ocean-like sound we hear when we place a seashell to our ears is due to an effect of resonance.
Resonance can also damage properties. The collapse of the Tacoma Narrows Bridge in Washington in 1940 was a result of resonance. The frequency of the wind was equal to the natural frequency of the bridge, thus setting the structure into vibration, and causing it to collapse.