What is true about RBCs in humans?
1. | They carry about 20-25 per cent of CO2 |
2. | They transport 99.5 per cent of O2 |
3. | They transport about 80 per cent oxygen only and the rest 20 per cent of it is transported in dissolved state in blood plasma |
4. | They do not carry CO2 at all |
Which two of the following changes (a – d) usually tend to occur in the plain dwellers when they move to high altitudes (3,500 m or more)?
(a) | Increase in red blood cell size |
(b) | Increase in red blood cell production |
(c) | Increased breathing rate |
(d) | Increase in thrombocyte count |
Changes occurring are:
1. (b) and (c)
2. (c) and (d)
3. (a) and (d)
4. (a) and (b)
1. | Inspiratory reserve volume plus tidal volume |
2. | Total lung capacity minus expiratory reserve volume |
3. | Inspiratory reserve volume plus expiratory reserve volume |
4. | Total lung capacity minus residual volume |
1. has a lower affinity for oxygen than that of the adult
2. its affinity for oxygen is the same as stat of an adult
3. has only 2 protein subunits instead of 4
4. has a higher affinity for oxygen than that of an adult.
Increased asthmatic attacks in certain seasons are related to:
1. hot and humid environment
2. eating fruits preserved in tin containers
3. inhalation of seasonal pollen
4. low-temperature
The 'blue baby' syndrome results from:
1. excess of chloride
2. methaemoglobin
3. excess of dissolved oxygen
4. excess of TDS (Total Dissolved Solids)
People living at sea level have around 5 million RBC per cubic millimeter of their blood whereas those living at an altitude of 5400 meters have around 8 million. This is because at high altitudes:
1. | people get pollution-free air to breathe and more oxygen is available |
2. | atmospheric O2 level is less and hence more RBCs are needed to absorb the required amount of O2 to survive |
3. | there is more UV radiation which enhances RBC production |
4. | people eat more nutritive food, therefore more RBCs are formed |
Which one of the following statements is incorrect?
1. | The residual air in the lungs slightly decreases the efficiency of respiration in mammals |
2. | The presence of non-respiratory air sacs increases the efficiency of respiration in birds |
3. | In mammals, circulating body fluids serve to distribute oxygen to tissues |
4. | The principle of countercurrent flow facilitates efficient respiration in the gills of fishes |
The majority of carbon dioxide produced by our body cells is transported to the lungs:
1. dissolved in the blood
2. as bicarbonates
3. as carbonates
4. attached to haemoglobin
Listed below are four respiratory capacities (1-4) and four jumbled respiratory volumes of a normal human adult.
Respiratory capacities | Respiratory volume | |
(a) | Residual volume | 2500 mL |
(b) | Vital capacity | 3500 mL |
(c) | Inspiratory reserve volume | 1200 mL |
(d) | Inspiratory capacity | 4500 mL |
Which one of the following is the correct matching of two capacities and volumes?
1. (a) 2500 mL, (d) 4500 mL
2. (c) 1200 mL, (a) 2500 mL
3. (b) 4500 mL, (c) 2500 mL
4. (d) 4500 mL, (b) 3500 mL