In the given diagram of the oxygen dissociation curve, under normal physiological conditions, the partial pressure of oxygen at the tissue level is represented by:
   
1. A
2. B
3. C
4. D

Which of the following result from the presence of free air in the pleural cavity?
1. pneumothorax and atelectasis
2. hydrothorax and hemothorax
3. empyema and emphysema
4. all of the above

Match each item in Column I with one item in Column II and chose your answer from the codes given below:
Column I                              Column II
(respiratory volume)              (value)
I. TV                                    1. 2500 mL - 3000 mL
II. IRV                                 2. 500 mL
III. ERV                               3. 1100 mL - 1200 mL
IV. RV                                  4. 1000 mL - 1100 mL 
Codes:
I II III IV
A. 1 2 3 4
B. 2 1 4 3
C. 2 1 3 4
D. 1 2 4 3

When fully saturated, the number of molecules each hemoglobin molecule can carry is:
1. one
2. two
3. three
4. four

Arrange the following modes of transport of carbon dioxide in the blood from the most common to the least common.
1. bicarbonate ions
2. combined with blood proteins
3. dissolved in plasma
Choose the arrangement that lists them in the correct order from largest to smallest percentage of carbon dioxide transported.
1. 1, 2, 3
2. 1, 3, 2
3. 2, 3, 1
4. 2, 1, 3

A combination of carbon dioxide and hemoglobin, CO2HHb, being one of the forms in which carbon dioxide exists in the blood is the
1. oxyhemoglobin.
2. deoxyhemoglobin.
3. carboxyhemoglobin.
4. carbaminohemoglobin

According to Bohr's effect

1.  Hemoglobin oxygen binding affinity is inversely related to acidity.

2.  Hemoglobin oxygen binding affinity is inversely related to concentration of ${\mathrm{CO}}_2$.

3.  Hemoglobin oxygen binding affinity is directly related to acidity.

4.  Both 1 and 2.

Consider the characters of a respiratory control center in humans:
I. It is located in pons
II. It moderates the functions of respiratory rhythm center
III. Its absence results in an increase in depth of respiration

The respiratory control center is:

1. Pneumotaxic center

2. Apneustic center

3. Chemosensitive zone

4. Dorsal group

Which of the following situations would result in the greatest degree of ${\mathrm{O}}_2$ saturation for haemoglobin, assuming ${\mathrm{PO}}_2$ remains constant-

1.  Increased ${\mathrm{H}}^{+}$ levels, decreased temperature.

2.  Increased ${\mathrm{CO}}_2$ levels, increased acidity.

3.  Decreased ${\mathrm{CO}}_2$ levels, decreased acidity.

4.  Increased ${\mathrm{CO}}_2$ levels, increased temperature.

Which of the following disease is caused mainly due to cigarette smoking

1. Asthma

2. Emphysema

3. Bronchitis

4. Rhinitis