Question

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

• A. Cigarette smoking may lead to inflammation of bronchi.
• B. Neural signals from pneumotaxic centre in pons region of brain can increase the respiratory rate.
• C. Workers in grinding and stone-breaking industries may suffer from Lung fibrosis.
• D. About 90% of carbon dioxide ($C{O}_2$) is carried by haemoglobin as carbaminohaemoglobin.

Answer 1

The correct option is D About 90% of carbon dioxide ($C{O}_2$) is carried by haemoglobin as carbaminohaemoglobin.

Most of the Carbon dioxide is carried in the form of bicarbonate ions.

Grinding or stone breaking industries produce so much dust that long exposure to this can give rise to inflammation of lungs leading to fibrosis (proliferation of fibrous tissues) and thus causing serious lung damage. Inflammation of the bronchi may also be caused by cigarette smoking. The primary function of pneumotaxic centre is to limit inspiration which increases breathing rate.

Hence the correct option is D.