10th Class Chapter No.1
Biology MCQs Online Quiz
All MCQs Selected from Old Board Papers
Best MCQs for Board Examination
Total MCQs ( in this Quiz ) = 50
81. The respiratory center is sensitive to the:
A. Concentration of carbon dioxide in the blood
B. Concentration of oxygen in the blood
C. Concentration of water in the blood
D. Concentration of nitrogen in the blood
Answer:
A. Concentration of carbon dioxide in the blood
82. Our muscle cells carry out cellular respiration at greater rate when we do
A. exercise or some hard job
B. relax
C. sleep
D. eat
Answer:
A. exercise or some hard job
83. During exercise or hard physical works:
A. The breathing rate may increase upto 30 – 40 times per minute.
B. The breathing rate may increase upto 32 – 40 times per minute.
C. The breathing rate may increase upto 34 – 40 times per minute
D. The breathing rate may increase upto 36 – 40 times per minutes
Answer:
A. The breathing rate may increase upto 30 – 40 times per minute.
84. What is amount of oxygen in inspired air?
A. 21%
B. 22%
C. 24%
D. 26%
Answer:
A. 21%
82. Amount of CO2 in inspired air?
A. 0.03%
B. 0.04%
C. 0.05%
D. 0.06%
Answer:
B. 0.04%
