Give the significance of respiration.

Assertion ($\mathrm{A}$): Anaerobic respiration yields less energy utilizing oxygen.

Reason ($\mathrm{R}$): In anaerobic respiration, energy is released due to the incomplete breakdown of organic molecules.

Assertion ($\mathrm{A}$): Biconcave shape of mammalian $\mathrm{RBC}$ facilitates gas exchange.

Reason ($\mathrm{R}$): Biconcave shape provides a high surface to volume ratio.