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All Free Biology MCQs with Answers

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19,844 questions · page 812 of 993

16221. What helps in voice production, when vibrated by air:

  • A. Larynx
  • B. Voicebox
  • C. Vocal cords
  • D. Pharynx

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Correct answer: Vocal cords

16222. In mammals, voice is produced by:

  • A. Bronchus
  • B. Larynx
  • C. Syrinx
  • D. Inhalation and exhalation

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Correct answer: Larynx

16223. Which of the following is the correct sequence of the air passage in man?

  • A. Nasal cavity→pharynx→trachea→larynx→bronchi→bronchioles→alveoli
  • B. Nasal cavity→pharynx→larynx→trachea→bronchi→bronchioles→alveoli
  • C. Nasal cavity→larynx→pharynx→trachea→bronchi→bronchioles→alveoli
  • D. Nasal cavity→larynx→bronchi→pharynx→trachea→bronchioles→alveoli

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Correct answer: Nasal cavity→pharynx→larynx→trachea→bronchi→bronchioles→alveoli

16224. Each lung is enclosed supply in two membranes called pleura. The membrane which closely covers the lung is called:

  • A. Parietal pleura
  • B. Visceral pleura
  • C. Peritoneum pleura
  • D. Lung pleura

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Correct answer: Visceral pleura

16225. Lungs have a large number of alveoli for:

  • A. Having spongy texture and proper shape
  • B. More surface area for diffusion of gases
  • C. More space for increasing the volume of inspired air
  • D. More nerve supply

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Correct answer: More surface area for diffusion of gases

16226. Which of the following prevents the collapsing of the trachea?

  • A. Diaphragm
  • B. Ribs
  • C. Cartilaginous discs
  • D. Muscles

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Correct answer: Cartilaginous discs

16227. Which one of the following is NOT true?

  • A. Blood from the right side of the heart is carried to the lungs by the pulmonary artery
  • B. Pleura are double covering of kidney
  • C. Pancreas is both exocrine and endocrine gland
  • D. Scurvy is due to a vitamin C deficiency

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Correct answer: Pleura are double covering of kidney

16228. Carbonic anhydrase is present in high concentration in:

  • A. Plasma
  • B. Erythrocytes
  • C. Leucocytes
  • D. Neurons

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Correct answer: Erythrocytes

16229. Arrange the following steps of respiration properly:1. Breathing or pulmonary ventilation by which atmospheric air is drawn in and CO2 2. Diffusion of gases (O2 and CO2) across the alveolar membrane.3. Transport of gases by the blood4. Diffusion of O2 and CO2 between blood and tissues.5. Utilization of O2, by the cells for catabolic reactions and resultant of CO2

  • A. 1,2,3,4,5
  • B. 1,3,2,5,4
  • C. 5,4,3,1,2
  • D. 3,4,5,2,1

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Correct answer: 5,4,3,1,2

16230. _is the site of actual diffusion of O2 and CO2 between blood and atmospheric air.

  • A. All bronchi
  • B. All bronchioles
  • C. All bronchi and terminal bronchioles
  • D. Alveoli and their ducts

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Correct answer: Alveoli and their ducts

16231. Sites of gaseous exchange in lungs are:

  • A. Alveoli
  • B. Bronchi
  • C. Bronchioles
  • D. Pleura

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Correct answer: Alveoli

16232. The enzyme essential for the transport of CO2 as bicarbonate in the blood is:

  • A. Carboxypeptidase
  • B. Succinic dehydrogenase
  • C. Carbonic anhydrase
  • D. Thrombokinase

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Correct answer: Carbonic anhydrase

16233. Which of the following factors at the tissue level favor the dissociation of oxygen from oxyhemoglobin?

  • A. High pO2, high pCO2, high H+ ,high temperature
  • B. Low pO2, high pCO2, high H+, high temperature
  • C. Low pO2, high pCO2, low H+, low temperature
  • D. High pO2, Low pCO2, Low H+, Low temperature

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Correct answer: Low pO2, high pCO2, high H+, high temperature

16234. Mast cells of connective tissue contain:

  • A. Vasopressin and relaxin
  • B. Heparin and histamine
  • C. Heparin and calcitonin
  • D. Serotonin and melanin.

Explanation: Mast cells are the large cells with densely granular cytoplasm that is found in connective tissues.

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Correct answer: Heparin and histamine

16235. Mast cells secrete:

  • A. Haemoglobin
  • B. Hippurin
  • C. Myoglobin
  • D. Histamine

Explanation: Mast cells are granulated wandering cells that are found in connective tissue. Their granules contain histamine which is a vasodilator.

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Correct answer: Histamine

16236. The ciliated columnar epithelial cells in humans are known to occur in:

  • A. The Eustachian tube and stomach lining
  • B. The bronchioles and Fallopian tube
  • C. The bile duct and oesophagus
  • D. The Fallopian tubes and urethra

Explanation: The ciliated columnar epithelial cells in humans are present in the nasal passages, oviducts (Fallopian tubes) terminal bronchioles…

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Correct answer: The bronchioles and Fallopian tube

16237. In man and mammals air passes from outside into the lungs through:

  • A. Nasal cavity, larynx, pharynx, trachea, bronchi, alveoli
  • B. Nasal cavity, larynx, pharynx, trachea, bronchioles, alveoli
  • C. Nasal cavity, pharynx, larynx, trachea, bronchioles, bronchi, alveoli
  • D. Nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli

Explanation: Air passes from nostrils into the nasal cavity where the dust particles are trapped.

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Correct answer: Nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli

16238. In which plant tissue does photosynthesis primarily occur?

  • A. Mesophyll
  • B. Epidermis
  • C. Cortex
  • D. Xylem

Explanation: Photosynthesis primarily occurs in the mesophyll tissue of plant leaves.

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Correct answer: Mesophyll

16239. The function of cilia in the respiratory passage is to keep the airways clear of:

  • A. Carbon dioxide
  • B. Oxygen
  • C. Dust
  • D. Carbon Monoxide

Explanation: Cilia, tiny hair-like structures lining the respiratory passages, play a crucial role in clearing dust and other particulate matter by…

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Correct answer: Dust

16240. In the lungs, the air is separated from the venous blood through:

  • A. Transitional epithelium + tunica externa of blood vessel
  • B. Squamous epithelium + endothelium of blood vessel
  • C. Squamous epithelium + tunica media of blood vessel
  • D. None of the above

Explanation: In the lungs, the air in the alveoli is separated from the venous blood in capillaries by the thin squamous epithelium of the alveoli and…

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Correct answer: Squamous epithelium + endothelium of blood vessel
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