Monday, December 31, 2012

Revision : Form 3 chapter 1 (Respiration)


Revision Question:
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Answers download here

Credit to all those JUs yang contribute soalan-soalan ni..Hopefully dapat jadi ilmu yang bermanfaat..TQ..

Respiration
Credit to http://ptbestari.blogspot.com/
http://ptbestari.blogspot.com/2008/12/science-form-3-respiration.html

Why do you need to breathe?
- To live
- To get energy
All the cells in your body require oxygen. Without it, they couldn't move, build, reproduce, and turn food into energy. In fact, without oxygen, they and you would die! Breaking of glucose with the present of oxygen to produce carbon dioxide and water and energy is something tested in PMR exams.

Glucose + oxygen ---> carbon dioxide + water + energy

How do you get oxygen? From breathing in air which your blood circulates to all parts of the body.



How do you breathe?
You breathe with the help of your diaphragm and other muscles in your chest and abdomen. These muscles literally change the space and pressure inside your body to accomodate breathing. When your diaphragm pulls down, it not only leaves more space for the lungs to expand but also lowers the internal air pressure. Outside, where the air pressure is greater, you suck in air in an inhale. The air then expands your lungs like a pair of balloons. When your diaphragm relaxes, the cavity inside your body gets smaller again. Your muscles squeeze your rib cage and your lungs begin to collapse as the air is pushed up and out your body in an exhale.

So, it all starts at the nose?
Yup. About 20 times a minute, you breathe in. When you do, you inhale air and pass it through your nasal passages where the air is filtered, heated, moistened and enters the back of the throat. Interestingly enough, it's the esophagus or foodpipe which is located at the back of the throat and the windpipe for air which is located at the front. When we eat, a flap -- the epiglottis -- flops down to cover the windpipe so that food doesn't go down the windpipe.

So -- back to breathing -- the air has a long journey to get to your lungs. It flows down through the windpipe, past the voice box or vocal cords, to where the lowermost ribs meet the center of your chest. There, your windpipe divides into two tubes which lead to the two lungs which fill most of your ribcage. Inside each of your sponge-like lungs, tubes, called bronchi, branch into even smaller tubes much like the branches of a tree. At the end of these tubes are millions of tiny bubbles or sacs called aleoli. Spread out flat, all the air sacs in the lungs of an adult would cover an area about the third of a tennis court.

What do these sacs do?
They help perform an incredible magic act. Your air sacs bring new oxygen from air you've breathed to your bloodstream. They exchange it for waste products, like carbon dioxide, which the cells in your body have made and can't use.

How does this exchange work?
With the help of the red blood cells in your bloodstream. Your red blood cells are like box cars on train tracks. They show up at the sacs at just the right time, ready to trade in old carbon dioxide that your body's cells have made for some new oxygen you've just breathed in. In the process, these red blood cells turn from purple to that beautiful red color as they start carrying the oxygen to all the cells in your body.

But what happens to the carbon dioxide?
It goes through the lungs, back up your windpipe and out with every exhale. It's a remarkable feat, this chemical exchange and breathing in and out. You don't have to tell your lungs to keep working. Your brain does it automatically for you.

Factoids
Your lungs contain almost 1500 miles of airways and over 300 million alveoli.
Every minute you breathe in 13 pints of air.
Plants are our partners in breathing. We breathe in air, use the oxygen in it, and release carbon dioxide. Plants take in carbon dioxide and release oxygen. Thank goodness!
People tend to get more colds in the winter because we're indoors more often and in close proximity to other people. When people sneeze, cough and even breathe -- germs go flying!

In summary student need to understand how and why air enters the lungs during inhalation and why and how it leaves the lungs during exhalation.

This must be memorized by students
a) 5 steps during inhalation and exhalation
b) Structure of lungs which consists of nasal cavity, trachea, bronchus, bronchioles and alveolus.

5 steps in inhalation
a) external intercostal muscles contract while internal set relaxes.
b) Diaphragm contracts and flatten
c) Ribs cages moves upwards and outwards. This increase volume of thoracic cavity and decreasing the pressure.
d) Pressure in lungs is lower than the atmospheric pressure.
e) Air from outside enters the lungs






1 nose
A nose is a nose is a nose. Smelling, tasting and breathing all start here. The size, location, mucous lining and tiny hairs (cilia) inside help prevent foreign objects to enter and to trap large air impurities before being drawn further into the respiratory system. Achooo! Out with the bad... bugs and carbon dioxide.

2 mouth
Mouth breathing can also be remembered as 'the big gulp', or 'plan 'B'' for air entry. Like the nose, it has many functions. It is the starting point of the digestive system as well as a secondary inhaler and exhaler.

3 larynx
The larynx has three main functions: 1) a passageway for air, 2) a valve to close off the air passage from the digestive one (the epiglottis) like a hinged trap door, and 3) as a voice box.
This is only for information and will not be testing in PMR

4 lung
The lungs are the essential organs of respiration. The main function of the lungs is to exchange carbon dioxide for oxygen and vice versa. Each lung is enclosed separately within two membranes, like a balloon inside a bag inside a bag.

5 right bronchus ^^ There are 2 main bronchi (Latin plural of bronchus): the right and left, each leading to a lung. If you accidentally breathe, or aspirate, a very small piece of food that gets past the trachea, it is most likely to fall and be pulled into the right main bronchus. If a peanut gets this far, what do you think could happen?

6 diaphragm This muscular structure acts as a floor to the chest (thoracic) cavity as well as a roof to the abdomen. It helps to expand and contract the lungs, forcing air into and out of them.

7 pharynx* The pharynx is shared with the digestive system from the tongue down to the epiglottis. Food goes on down the esophagus and air passes on through the trachea - but never both at the same time!

8 trachea* ^^ This armored tube allows air to pass beyond the larynx to where it divides into the left and right bronchi. The protective 'c's of cartilage also provide protection to the digestive system's esophagus right behind it.

9 left bronchus ^^ The left one has a sharper bend due to the presence of the heart and major blood vessels directly underneath it.

10 bronchiole ^^ Each bronchus divides and subdivides into smaller and smaller branches, the bronchioles, just like tree branches that get smaller as they grow up and out. By the time the air has reached here from outside, it has been warmed up to body temperature, filtered and moisturized.

11 alveoli These tiny air cells, or sacs, are the 'leaves' of our respiratory tree. They resemble bunches of grapes and are the link between the respiratory and circulatory systems. Gas exchange happens here - I'll trade you fresh oxygen (O2) for your used carbon dioxide (CO2). Now trace the route of the old air back out to the nose.

* throat The throat includes all the structures lying in front of the spinal column including the mouth, tongue, pharynx, tonsils, larynx and trachea.
* trachea, bronchi and bronchioles These three portions of our airways also have rings of muscle along their length as well as glands lining them. These glands produce mucous that traps particles of dirt. Eventually, this sticky stuff and its trapped dirt are coughed up and cleared out. With asthma, these sensitive muscles tighten, making all the airways smaller and more difficult to breath through, and excessive mucus is produced, sometimes flooding the airways.

Respiratory Diseases
1) Lung cance
2) Chronic bronchitis (bronchi become inflammed and narrowed)
3) Emphysema - burst of alveoli during caughing.
4) Asthma - narrowing of air passage
5) Tuberculosis (TB) - bacteria infection.

Harmful Substances to Respiratory System
1) Tar - present in cigaratte
2) Nicotine - addiction to smoking
3) CO - reduces the oxygen -carrying power of blood
4) SO - corrodes the walls of the air passage.
5) Asbestos dust - breathing difficulty. It is carcinogen and cause lung cancer
6) Toxis - cause pneumonia and tuberculosis
7) Haze - cause throat irritation, inflammation of the respiratoryh tract and breathing difficulties

Sunday, October 14, 2012

Skema Jawapan Sains PMR 2012


1. C
2. A
3. D
4. C
5. B
6. C
7. C
8. C
9. C
10. A
11. B
12. A
13. A
14. C
15. C
16. D
17. B
18. D
19. D
20. A
21. A
22. A
23. A
24. B
25. B
26. D
27. B
28. A
29. B
30. A
31. D
32. D
33. C
34. D
35. B
36. A
37. B
38. D
39. B
40. C

Saturday, September 29, 2012

Himpunan Soalan Chapter 6 - Percubaan Sains PMR 2012

Soalan-soalan Chapter 6 daripada Soalan Percubaan Negeri 2012

SBP - SILICON 
MRSM - METAL & NON METAL / CALCIUM CARBONATE
KEDAH - CALCIUM CARBONATE
NEGERI SEMBILAN - CALCIUM CARBONATE

Download di sini

Sunday, September 9, 2012

Soalan Percubaan Sains Semua Negeri PMR 2012


Kedah 2012

Kelantan 2012

Terengganu 2012

Melaka 2012

Negeri Sembilan 2012

Pahang 2012
Paper 1 || Paper 2 || Answer Scheme P1 P2

Perak 2012

SBP 2012
Paper 1 || Paper 2 || Answer Scheme P1 P2

Selangor 2012
Paper 1 || Paper 2 || Answer Scheme P1 P2
Credit to blogsciencepmr.blogspot.com

Pulau Pinang 2012
Paper 1 || Paper 2 || Answer Scheme P1 P2
Credit to blogsciencepmr.blogspot.com

Perlis 2012

MRSM 2012
Paper 1 || Paper 2 || Answer Scheme P1 P2
Credit to blogsciencepmr.blogspot.com

JOHOR 2012
Paper 1 || Paper 2 || Answer Scheme P1 P2
Credit to blogsciencepmr.blogspot.com


Saturday, May 5, 2012

Revision : Form 3 CHAPTER 5 ( Growth )

Revision Question:
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Credit to all those JUs yang contribute soalan-soalan ni..Hopefully dapat jadi ilmu yang bermanfaat..TQ..

Revision : Form 3 CHAPTER 4 (Reproduction)


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Revison Form 3 : CHAPTER 3 ( Excretion )


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Revision : Form 3 chapter 2 (Blood Circulation and Transport)


Revision Question:
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Science Form 3 (Chapter 2) Blood Circulation and Transport

Introduction to function of Heart

The role of the heart is to pump oxygen-rich blood to every living cell in the body. In order to achieve its goal, it must continuously beat for a person’s entire lifespan. Because of its vital role, a non-beating heart always results in death. The human heart beats approximately 80,000 to 100,000 a day and pumps almost 2,000 gallons of blood. This means that in a person’s life lasting 70 to 90 years, the heart beats approximately two to three billion times and pumps 50 to 65 million gallons of blood. Because the heart is so essential for human sustenance, it is made up of a muscle different from skeletal muscle that allows it to constantly beat.

In order for the heart to deliver oxygenated blood to all cells, blood is pumped through arteries. Veins bring deoxygenated blood cells to the lungs, which then are oxygenated, and then sent back to heart. In this way, a continuous cycle is formed of the heart pumping oxygenated blood and deoxygenated blood out to their designated destinations, and therefore the heart maintains the circulatory system.



Systole: Stage when the ventricles of heart are contracting resulting in blood being pumped out to the lungs and the rest of the body.
- Thick, muscular walls of both ventricles contract.
- Pressure rises in both ventricles, causing the bicuspid and tricuspid valves to close. Therefore, blood is forced up the aorta and the pulmonary artery.
- The atria relax during this time. The left atrium receives blood from the pulmonary vein, and the right atrium from the vena cava.



Diastole: Stage when the ventricles of the heart are relaxed and not contracting. During this stage, the atria are filled with blood and pump blood into the ventricles.
- Thick, muscular walls of both ventricles relax.
- Pressure in both ventricles falls low enough for bicuspid valves to open.
- The atria contract, and blood is forced into the ventricles, expanding them. The blood pressure in the aorta is decreased, therefore the semi-lunar valves close.










Revision Form 3 : Menstrual Cycle


Download questions & answers here or here


Credit to all those JUs yang contribute soalan-soalan ni..Hopefully dapat jadi ilmu yang bermanfaat..TQ..

Monday, March 12, 2012

Q&A Form 3 : Chapter 3 (Structure of Kidney)

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Q&A Form 3 : Chapter 3

Click on the pictures to enlarge

Q&A Form 3 : Chapter 2


State two functions of the system in Diagram 3.
Nyatakan  dua fungsi sistem di Rajah 3.

1. P (phloem) : carry food

2. Q (xylem) : carry water and mineral salts

Q&A Form 3 : Chapter 1




a) Name the process of the human breathing mechanism when the rubber sheet is pulled downwards.
    Namakan proses dalam mekanisme pernafasan manusia apabila kepingan getah ditarik ke bawah.
Inhalation
                                                                                          

b) Name the parts in the human respiratory system that is analogous to the apparatus below:
    Namakan bahagian dalam sistem respirasi manusia yang menyamai radas di atas:


i)  glass tube - trachea
ii) Y-shaped glass tube - bronchus
iii) Balloon - lungs
iv) Bell jar - thoracic cavity

c) Name three diseases that affect human lungs.
    Namakan tiga penyakit yang memberi kesan kepada peparu manusia.

i) lung cancer
ii) bronchitis
iii) asthma

d) What are the harmful effect  to the respiratory system of the following harmful substances in the    
    cigarette smoke.
    Apakah kesan buruk terhadap sistem pernafasan manusia bagi bahan yang terdapat dalam asap
    rokok berikut:

     a)  Nicotine  : cause addiction
     b)  Tar          : blackens the lungs
     c) Carbon monoxide : reduce the amount of oxygen in blood




Monday, January 23, 2012

Azimat Menempuh Peperiksaan - From saifulislam.com

Azimat Menempuh Peperiksaan
Abu Saif | 07/10/2009 | 10:57 am | 2,829 views | Print Print | Email Email
BACKDROP-PMR
“Bolehkah kamu berjaya dalam hidup jika tidak lulus PMR dan SPM?” saya melontarkan soalan kepada peserta.
Boleh tahan juga bilangannya yang mengangkat tangan untuk jawapan YA.
“Maknanya ramailah yang merancang untuk gagal PMR dan SPM ni ya? Senang kerja saya” saya membuat kesimpulan.
Guru-guru pun ada yang kelihatan resah dengan idea yang saya sampaikan. Memberikan cadangan bahawa hidup boleh diteruskan dengan kejayaan tanpa kelulusan PMR dan SPM?

“Baiklah, bagi yang kata kita boleh berjaya dalam hidup walaupun gagal PMR dan SPM, bolehkah kongsikan hujah anda?” saya menyambung provokasi.
Seperti biasa, ramai yang tertunduk-tunduk, memandang dinding dan bumbung dewan, melarikan mata daripada memandang saya kerana tidak mahu disuruh menjawab soalan. Itu ‘penyakit’ yang sering melanda pelajar-pelajar kita. Bising bila ramai, kecut bila diminta bersuara atas kapasiti peribadi.
“Sebab PMR dan SPM bukan segala-galanya. Ada ujian yang lebih besar di Akhirat!” jawab seorang pelajar.
Wah, jawapannya disambut dengan tepuk tangan oleh rakan-rakan. Saya juga mengucapkan syabas kepadanya kerana berani bersuara. Senaskhah buku Persediaan Minda Pelajar Cemerlang tulisan rakan saya, Osman bin Affan, dijadikan hadiah buat pelajar yang berani ini.
PMR DAN SPM URUSAN AKHIRAT
“Maksud kamu, PMR dan SPM tiada kena mengena dengan Akhirat?” saya menyambung soalan.
“Err… err…” pelajar itu tidak pasti, asyik menggaru kepala.
“Ada ke benda di dunia ini yang tiada kena mengena dengan Akhirat?” saya meneruskan soalan.
“Sekular!” jawab seorang pelajar.
Hebat falsafahnya. Senaskhah lagi buku Motivasi Alihan Pelajar tulisan Dr. Tengku Asmadi, saya jadikan hadiah buat pelajar yang memberikan kata kunci berharga dalam sampuk beliau itu tadi.
Hakikatnya, sama ada kita boleh berjaya atau tidak dalam hidup ini tanpa lulus PMR dan SPM, jawapannya ialah YA dan TIDAK.
JIKA MAHU JAWAPANNYA YA
Anda berusaha gigih.
Pergi ke sekolah dan menghadiri kelas dengan penuh tumpuan. Tidak ponteng kelas tambahan. Bertanya jika tidak faham. Membuat kerja latihan yang diberi, berlatih menjawab soalan-soalan tahun lepas, mencipta mnemonic untuk membantu anda menghafal fakta… anda berusaha dengan bersungguh-sungguh.
Tiba-tiba menjelang peperiksaan, berlaku sesuatu yang tidak dijangka.
Anda demam campak.
Seperti semasa saya menduduki kertas pertama SPM, kertas Bahasa Melayu.
Disebabkan oleh perkara-perkara yang tidak dijangka itu, anda mendapat keputusan peperiksaan yang tidak seperti apa yang diharapkan, malah mungkin gagal terus… ketahuilah, anda adalah calon manusia berjaya dalam hidup ini di dunia dan di Akhirat.
Mengapa?
UPSR, PMR dan SPM walaupun kejayaannya diukur pada keputusan yang tercatat di atas kertas keputusan peperiksaan, namun itu bukanlah inti pati utamanya. Tanyalah seorang jurutera, semasa beliau menghadiri temuduga kerja, apakah majikannya bertanya tentang keputusan UPSR dan PMR beliau?
Tiada.
Sudah tidak penting lagi.
srp
Di usia ini, gred berapa dan agregat berapa sudah tidak penting, tetapi SIKAP yang terbentuk daripadanya berguna sepanjang hayat
Tetapi apa yang diajar oleh UPSR, PMR dan SPM ialah latihan mencipta kejayaan iaitu pada SIKAP yang dibentuk di sepanjang perjalanan menuju dewan peperiksaan. Jika anda telah berusaha gigih, memberikan sepenuh komitmen, berdisiplin untuk mengutamakan apa yang utama, bersabar dengan apa yang kita tidak suka untuk nantinya dapat apa yang kita suka, maka kita sudah pun berjaya, sebelum keluar keputusan peperiksaan!.
Kejayaan ialah perjalanan, bukan destinasi!
Jika anda sudah menyertai perjalanan itu, anda sudah pun berjaya.
JAWAPANNYA PASTI TIDAK
Namun, jika anda gagal di dalam peperiksaan kerana tidak berusaha, malas, menyakiti hati ibu bapa dan guru, maka ketahuilah anda adalah calon manusia gagal di dunia dan di Akhirat.
“Tapi ustaz, Tan Sri Dato’ Loh Boon Siew jadi jutawan walaupun tak sekolah!” kata seorang pelajar merujuk kepada Honda Man, tokoh perniagaan negara yang amat terkenal itu.
“Dia jadi jutawan bukan dengan menggagalkan diri di dalam peperiksaan. Kamu tahu, Mendiang Boon Siew bekerja mengutip tahi babi semasa di usia kamu untuk menyara hidupnya. Ia lebih hebat daripada kesanggupan kamu berjalan kaki ke kelas tambahan di sekolah pada tengah hari yang panas terik di bulan puasa! Itulah SIKAP!” saya menambah.
Nampaknya pelajar-pelajar ini sudah panas. Sudah berani menjawab. Sebuah lagi buku MAGNET DIRI tulisan Amin Idris saya hadiahkan kepadanya.
“Macam mana boleh gagal PMR dan SPM membawa kepada kegagalan di Akhirat, ustaz?” tanya seorang pelajar.
“Dunia ladang Akhirat. Macam yang ustaz sebut tadi, kalau kegagalan peperiksaan itu berpunca daripada sikap atau akhlaq yang buruk, menyakiti hati guru-guru dan ibu bapa yang bersusah payah mahukan kejayaan untuk kamu, itulah dosa yang menjadi saham untuk membeli kerusi di lubuk Neraka!” saya menambah.
Ceramah berlangsung lagi hingga selesai satu jam setengah masa yang diberikan.
Tiada apa-apa resepi kejayaan rahsia yang saya berikan.
Bak kata bapa kepada hero pujaan filem kegemaran saya yang wajahnya mirip-mirip saya:
kungfupanda-rahsia
“There is no secret ingredient, you just have to believe! – Abu Panda”
Selamat menempuh peperiksaan PMR untuk adik-adik yang menduduki kertas pertama mereka hari ini.
Jika ada soalan yang tidak diketahui jawapannya, tuliskan sahaja WALLAHU A’LAM (Allah lebih mengetahui), pasti betul. Jangan ada pegawai pemeriksa yang memangkahnya. Rosak Aqidah!
Cuma, tiada markahlah… itu sahaja.
Ingat, kejayaan adalah perjalanan, bukan destinasi!
Seeru ‘alaa barakatiLlaah!
ABU SAIF @ www.saifulislam.com
68000 AMPANG
Taken from www.saifulislam.com
TQ for sharing Ustaz Hasrizal.

Science Form 3 Chapter 1 Mini Test

Science Form 3 Chapter 1 Mini Test

Test yourself!
A mini-test on your skill and knowledge about respiration!

Click here.

Credit to honsiong.

Science Form 3 Chapter 1 & 2-Pop Quiz


This is just a simple pop quiz about Science Form 3 Chapter 1 and 2.

Click here.

Credit to himiko.