In medical term, Jet Lag referred as desynchronizes which a physiological condition is caused by consequence of variations to circadian rhythms and it is classified as one of the circadian rhythm sleep disorders. It results from rapid far distance transmeridian travel, means east to west or west to east travel, on a jet plane. A state of exhaustion experienced by air travelers when they cross several time zones in a relatively short time as when one flies from India to U.S.A. The condition arises from disturbances in the body’s habitual rhythms of ‘internal clock’ by suddenly requiring it to adapt to a strange new 24-hour time-scale.

Time zones are imaginary lines that run from north to south on the map. These help standardize time throughout the world since it is only possible to cross them by traveling from east to west or vise versa, jet lag is therefore, experienced only when long distances are traveled along the east-west axis. A state of exhaustion experienced by air travelers when they cross several time zones in a relatively short time as when one flies from India to U.S.A. Jet lag generally included a feeling of fatigue, hunger at unexpected times, irregular bowel and bladder movements. The only way to combat it is adequate rest at the end of the flight.

The human genome is generally the genome of Homo sapiens, which are found in 23 pairs of chromosomes. Among twenty three pairs, twenty two are known as autosomal chromosome pairs; while the remaining one pair is sex determining pair choromosome.Human genome refers to the entire genetic make-up of humans. The genes giving rise to specific human characteristics, their variants and the regulatory genes that direct the functioning of other genes are collectively called the ‘human genome’. Roughly lakh genes are contained in about three billion base pairs present in every human cell. Presently, an international effort known as the ‘Human genome project’ is underway to identify and locate all the genes and their variants, understand their functioning, and write-down the sequence of nucleotides that comprise the genes. The project is aimed at producing a human genome map containing the entire sequence of nucleotides in the human DNA.

A better understanding of the human genome might help in diagnosing many hereditary diseases at an early stage or even before birth. It may also be helpful in finding cures for at least some of the hereditary diseases. Ultimately, the knowledge may also help to replace any defective or disease causing gene(s) with other gene(s) to restore health.