Q11. During exhalation, which muscle relaxes to decrease the volume of the thoracic cavity?
a) Diaphragm
b) External intercostal muscles
c) Internal intercostal muscles
d) Abdominal muscles
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Correct Answer: a) Diaphragm
Explanation: During exhalation, the diaphragm relaxes and moves upward, decreasing the volume of the thoracic cavity. This relaxation causes an increase in pressure within the lungs, facilitating the expulsion of air.
Q12. Which of the following gases is NOT involved in the process of respiration?
a) Nitrogen
b) Oxygen
c) Carbon monoxide
d) Hydrogen
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Correct Answer: a) Nitrogen
Explanation: Nitrogen is not directly involved in the process of respiration. While it is present in the air we breathe, it is considered an inert gas and does not participate in cellular respiration or gas exchange in the lungs.
Q13. Which respiratory disorder is characterized by the destruction of the alveolar walls, leading to reduced surface area for gas exchange?
a) Asthma
b) Bronchitis
c) Pneumonia
d) Emphysema
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Correct Answer: d) Emphysema
Explanation: Emphysema is a chronic respiratory condition characterized by the progressive destruction of the alveolar walls, leading to decreased elasticity and surface area in the lungs. This results in difficulty breathing and poor oxygen exchange.
Q14. What is the role of hemoglobin in the respiratory system?
a) Transporting oxygen in the bloodstream
b) Exchanging gases in the alveoli
c) Producing carbon dioxide
d) Converting glucose into ATP
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Correct Answer: a) Transporting oxygen in the bloodstream
Explanation: Hemoglobin is a protein found in red blood cells that binds to oxygen in the lungs and carries it through the bloodstream to tissues and organs where it is needed for cellular respiration.
Q15. Which of the following respiratory structures prevents food from entering the airway during swallowing?
a) Epiglottis
b) Larynx
c) Trachea
d) Bronchi
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Correct Answer: a) Epiglottis
Explanation: The epiglottis is a flap of tissue located at the base of the tongue that covers the opening of the trachea during swallowing, preventing food and liquid from entering the airway. This helps to protect the respiratory system from aspiration.
Q16. Which of the following animals utilizes book lungs for respiration?
a) Fish
b) Spider
c) Bird
d) Frog
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Correct Answer: b) Spider
Explanation: Spiders have a unique respiratory organ called book lungs, which are composed of layers of thin sheets resembling the pages of a book. These structures allow for gas exchange between the spider’s internal tissues and the surrounding environment.
Q17. Which part of the brain controls involuntary respiration?
a) Cerebrum
b) Cerebellum
c) Medulla oblongata
d) Hypothalamus
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Correct Answer: c) Medulla oblongata
Explanation: The medulla oblongata, located in the brainstem, controls involuntary functions such as breathing, heart rate, and blood pressure. It contains the respiratory center, which regulates the rate and depth of breathing based on the body’s needs.
Q18. Which of the following statements about anaerobic respiration is true?
a) It requires oxygen
b) It produces more ATP than aerobic respiration
c) It produces lactic acid in humans
d) It occurs in the mitochondria
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Correct Answer: c) It produces lactic acid in humans
Explanation: Anaerobic respiration is a process that occurs in the absence of oxygen and produces lactic acid as a byproduct in humans and other organisms. It is less efficient than aerobic respiration in terms of ATP production.
Q19. Which of the following is NOT a symptom of hyperventilation?
a) Rapid breathing
b) Dizziness
c) Shallow breathing
d) Increased carbon dioxide levels in the blood
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Correct Answer: d) Increased carbon dioxide levels in the blood
Explanation: Hyperventilation is characterized by rapid and deep breathing, which leads to a decrease in carbon dioxide levels in the blood (hypocapnia). Symptoms can include dizziness, lightheadedness, and tingling sensations.
Q20. Which respiratory disorder is characterized by inflammation of the bronchial tubes, leading to coughing and production of mucus?
a) Asthma
b) Bronchitis
c) Pneumonia
d) Emphysema
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Correct Answer: b) Bronchitis
Explanation: Bronchitis is a respiratory condition caused by inflammation of the bronchial tubes, which carry air to and from the lungs. Symptoms include coughing, wheezing, chest discomfort, and production of excess mucus.