Science PMR By M Smkdmscience
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Answer all question/Jawab semua soalan.
- 1.
1.Temperature can be measured in I Joules II Kelvin III Celsius IV Fahrenheit
- A.
I and III only
- B.
II and IV only
- C.
II, III and IV only
- D.
I, II, III and IV
Correct Answer
C. II, III and IV onlyExplanation
Temperature can be measured in Kelvin, Celsius, and Fahrenheit. Joules is not a unit of temperature measurement, but rather a unit of energy measurement. Therefore, the correct answer is II, III and IV only.Rate this question:
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- 2.
Which of the following is a source of heat?
- A.
A stone
- B.
A volcano
- C.
A stick
- D.
A mirror
Correct Answer
B. A volcanoExplanation
A volcano is a correct answer because it is a natural source of heat. Volcanoes are formed when molten rock called magma rises to the surface of the Earth. This magma is extremely hot and can reach temperatures of several thousand degrees Celsius. When the magma erupts from the volcano, it releases heat energy in the form of lava, ash, and gases. This heat can be intense enough to melt rocks and cause widespread destruction in the surrounding area. Therefore, a volcano is a significant source of heat.Rate this question:
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- 3.
3.Which of the following is not part of the human respiratory system?
- A.
Trachea
- B.
Ribs
- C.
Pulmonary artery
- D.
Intercostal muscles
Correct Answer
C. Pulmonary arteryExplanation
The pulmonary artery is not part of the human respiratory system. It is a blood vessel that carries deoxygenated blood from the heart to the lungs for oxygenation. The respiratory system is responsible for the exchange of gases, particularly oxygen and carbon dioxide, between the body and the environment. The trachea, ribs, and intercostal muscles are all directly involved in the process of breathing and are essential components of the respiratory system.Rate this question:
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- 4.
4.When we inhale, why is air pushed into the lungs?
- A.
The air pressure in the lungs decreases
- B.
The air pressure in the lungs increases
- C.
The lungs become smaller
- D.
The diaphragm curves upwards
Correct Answer
A. The air pressure in the lungs decreasesExplanation
When we inhale, the muscles in the diaphragm contract and move downwards, causing the volume of the chest cavity to increase. This increase in volume results in a decrease in air pressure within the lungs. As a result, air from the atmosphere rushes into the lungs to equalize the pressure, filling them with fresh oxygen.Rate this question:
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- 5.
5.What are the changes that take place when we exhale? I The rib cage moves down II The outer intercostal muscles relax III The thoracic cavity becomes bigger IV Air flows from the atmosphere into the lungs
- A.
I and II only
- B.
III and IV only
- C.
II, III and IV only
- D.
I, II, III and IV
Correct Answer
A. I and II onlyExplanation
When we exhale, the rib cage moves down, which is represented by statement I. This movement helps in reducing the volume of the thoracic cavity. Additionally, the outer intercostal muscles relax, as mentioned in statement II. This relaxation allows the rib cage to move down and aids in the exhalation process. However, there is no mention of the thoracic cavity becoming bigger or air flowing from the atmosphere into the lungs, so statements III and IV are not correct. Therefore, the correct answer is I and II only.Rate this question:
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- 6.
6.Which of the following is the correct sequence to show how air enters the lungs?
- A.
Trachea, bronchiole, lung, alveolus
- B.
Trachea, bronchus, bronchiole, alveolus
- C.
Bronchus, trachea, bronchiole, lung
- D.
Trachea, alveolus, bronchus, bronchiole
Correct Answer
B. Trachea, bronchus, bronchiole, alveolus -
- 7.
7. Which of the following correctly shows the contents of inhaled air and exhaled air? Gas Inhaled air Exhaled air I Oxygen 21% 16% II Carbon dioxide 0.03% 4% III Nitrogen 78% 87% IV Water vapour A little 50%
- A.
I and II only
- B.
III and IV only
- C.
II, III and IV only
- D.
I, II, III and IV
Correct Answer
A. I and II onlyExplanation
The correct answer is I and II only. This is because inhaled air contains a higher percentage of oxygen (21%) compared to exhaled air (16%). Additionally, inhaled air contains a lower percentage of carbon dioxide (0.03%) compared to exhaled air (4%). This information aligns with our understanding of the respiratory system, where oxygen is taken in during inhalation and carbon dioxide is expelled during exhalation.Rate this question:
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- 8.
8..Which of the following diseases is caused by smoking cigarettes? I Lung cancer II Emphysema III Bronchitis IV Hepatitis
- A.
I and II only
- B.
III and IV only
- C.
I, II and III only
- D.
I, II, III and IV
Correct Answer
C. I, II and III onlyExplanation
Smoking cigarettes can cause lung cancer, emphysema, and bronchitis. Lung cancer is a type of cancer that starts in the lungs and is strongly associated with smoking. Emphysema is a chronic lung disease that is caused by damage to the air sacs in the lungs, often due to smoking. Bronchitis is an inflammation of the bronchial tubes, which carry air to and from the lungs, and smoking is a common cause of chronic bronchitis. Hepatitis, on the other hand, is a viral infection that affects the liver and is not directly caused by smoking cigarettes.Rate this question:
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- 9.
9.Why are cigarette smokers sometimes short of breath?
- A.
Their lung tissue has turned black
- B.
Cigarette smoke reduces the amount of oxygen in the blood
- C.
Their lung tissue contains nicotine
- D.
There are many poisonous gases in their lymphatic system
Correct Answer
B. Cigarette smoke reduces the amount of oxygen in the bloodExplanation
Cigarette smoke contains harmful chemicals that can damage the lungs and airways. When smokers inhale cigarette smoke, these chemicals can irritate and inflame the airways, causing them to become narrow and blocked. This can lead to a decrease in the amount of oxygen that can enter the bloodstream, resulting in shortness of breath. Additionally, smoking can also lead to the development of chronic obstructive pulmonary disease (COPD), a progressive lung disease that can further contribute to breathing difficulties.Rate this question:
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- 10.
10..hich of the following pollutants is carcinogenic?
- A.
Tar
- B.
Nitrogen dioxide
- C.
Carbon monoxide
- D.
Carbon dioxide
Correct Answer
A. TarExplanation
Tar is the correct answer because it contains numerous toxic chemicals, including polycyclic aromatic hydrocarbons (PAHs), which are known to be carcinogenic. When tar is inhaled, it can cause damage to the respiratory system and increase the risk of developing lung cancer. Additionally, tar is commonly found in tobacco smoke, making it a significant contributor to the development of various types of cancer, including lung, throat, and mouth cancer.Rate this question:
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Mar 21, 2023Quiz Edited by
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Jul 23, 2010Quiz Created by
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