Questions

Economists use the concept of marginal utility to measure happiness and pleasure and how that affects consumer decision making. They have also identified the law of diminishing marginal utility, which means that the first unit of consumption of a good or service has more utility than the next units of consumption.Hence, the marginal utility of the good diminishes as the amount of good consumed increases.

The two DNA strands are called polynucleotidesbecause they are composed of simpler monomer units called nucleotides. Eachnucleotideis composed of one of four nitrogen-containingnucleobases (cytosine, guanine, adenine or thymine), a sugar called deoxyribose, and a phosphate group.

Error is in second part. Returning means coming back to place from where you began. So, the use of back after returned becomes redundant. Without using back, the meaning remains the same. We can omit ‘back’ in part b, and use ‘returned home.’

The human ear can respond to minute pressure variations inthe air if they are in the audible frequency range, roughly 20 Hz -20 kHz. In fact, tests conducted show an increased sensitivity in the 3000 Hz range which is the optimal amplification frequency in the human ear. So, the sensitivity of the human ear varies with the frequency of the sound.