The hormone $Melatonin$ is produced by the:

$I.$ Sleep-wake cycle,$II.$ Body temperature,$III.$ Pigmentation,$IV.$ Metabolism,$V.$ Defence capability. All of the above-mentioned activities are influenced/regulated by:

The function of the pineal body is to

Daily rhythms are usually associated with

The amino acid tryptophan is the precursor for the synthesis of

Select the correct match regarding the source and function of the hormone.