When under certain conditions, the P₅₀ value of haemoglobin rises, the affinity of the pigment of combining with O₂ will

1. Remain same

2. Rise

3. Fall

4. First rise and then fall

Hemoglobin that is bonded to carbon monoxide and therefore cannot transport oxygen, is called

1. carboxyhemoglobin

2. methemoglobin

3. reduced hemoglobin

4. carbaminohemoglobin

Which of the following does not shift the oxy-haemoglobin dissociation curve to the right?

1. increased pH

2. increased carbon dioxide

3. increased temperature

4. increased 2,3 -DPG

The solubility of carbon dioxide is about _____ times higher than that of oxygen across the respiratory membrane.

1. 20-25

2. 25-50

3. 125-150

4. 200-250

What amount of carbon dioxide is delivered by every 100 ml of deoxygenated blood to the alveoli?

1. 4 ml

2. 5 ml

3. 15 ml

4. 20 ml

The following statements refer to gas carriage by blood. Choose the correct statement:

When you hold your breath which of the following gas changes in blood would first lead to the urge to breathe?

(1) Falling O₂ concentration

(2) Rising CO₂ concentration

(3) Falling CO₂ concentration

(4) Rising CO₂ and falling O₂ concentration

Reduction in pH of blood will

(1) reduce the blood supply to the brain

(2) decrease the affinity of hemoglobin with oxygen

(3) release bicarbonate ions by the liver

(4) reduce the rate of heart beat

Approximately seventy percent of carbon dioxide absorbed by the blood will be

transported to the lungs

1. as bicarbonate ions

2. in the form of dissolved gas molecules

3. by binding to RBC

4. as carbamino-haemoglobin

Which one of the following is the correct statement for respiration in humans?

1. Cigarette smoking may not lead to inflammation of bronchi

2. Neural signals from pneumotoxic centre in pons region of brain can increase the

duration of inspiration

3. Workers in grinding and stone breaking industries may suffer, from lung fibrosis

4. About 90% of carbon dioxide ($C{O}_2$) is carried by haemoglobin as carbamino haemoglobin