NEET Practice Questions (MCQs) with Answers & Solutions

The NCERT clearly states, 'As the solubility of CO2 is 20-25 times higher than that of O2, the amount of CO2 that can diffuse through the diffusion membrane per unit difference in partial pressure is much higher compared to that of O2.'

The NCERT states, 'The diffusion membrane is made up of three major layers namely, the thin squamous epithelium of alveoli, the endothelium of alveolar capillaries and the basement substance...'

The NCERT states, 'Every 100 ml of oxygenated blood can deliver around 5 ml of O2 to the tissues under normal physiological conditions.'

The NCERT states, 'Nearly 20-25 per cent of CO2 is transported by RBCs whereas 70 per cent of it is carried as bicarbonate. About 7 per cent of CO2 is carried in a dissolved state through plasma.'

The NCERT mentions, 'In the alveoli, where there is high pO2, low pCO2, lesser H+ concentration and lower temperature, the factors are all favourable for the formation of oxyhaemoglobin...'

The NCERT states, 'Binding of oxygen with haemoglobin is primarily related to partial pressure of O2. Partial pressure of CO2, hydrogen ion concentration and temperature are the other factors which can interfere with this binding.'

The NCERT text states: 'The work of Mendel and others who followed him gave us an idea of inheritance patterns. However the nature of those ‘factors’ which determine the phenotype was not very clear. As these ‘factors’ represent the genetic basis of inheritance, understanding the structure of genetic material and the structural basis of genotype and phenotype conversion became the focus of attention in biology for the next century.' This directly supports option 2.

The context explicitly lists 'Watson, Crick, Nirenberg, Khorana, Kornbergs (father and son), Benzer, Monod, Brenner' as major contributors to molecular biology. Louis Pasteur is not mentioned in this list.

The NCERT text states: 'However the nature of those ‘factors’ which determine the phenotype was not very clear.' This indicates that the chemical or structural identity of the genetic material (factors) was the missing piece.

The text reads: 'Awareness in the areas of molecular genetics, structural biology and bio informatics have enriched our understanding of the molecular basis of evolution.' This directly points to the correct option.