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Genes, the fundamental units of inheritance are passed down from parents to offspring, and are present in every cell of our body. Organisms inherit all, the good and the bad through genes packed into chromosomes. Pairs make pairs
Chromosomes are ribbon-like structures that are inherited from both parents (50% from each), and are present in pairs in every cell. The sex of most organisms, including humans is determined by the inheritance of chromosomes. Humans have 23 pairs of chromosomes, of which the 23rd pair determines the sex of the individual. A collection of the 23 pairs of chromosomes is known as 'karyotype'.
Female Karyotype
Reproduction, the fundamental life process that ensures that life continues on earth relies completely on the process of the two half sets of chromosomes coming together to form one cell, which further divides until an organism is formed.
Answers that led to questions
The discovery of genes, although elating at first, led to several baffling questions; how does an entire organism develop from the several permutations and combinations of genes? If genes are considered to be blueprints, what are the building materials that enable the development and regulation of life? The search for an answer led to ‘proteins’ made up of ‘amino acids’ (YES! Proteins were discovered before any of the other life’s molecules).
Suddenly, it all made perfect sense!
The CENTRAL DOGMA as we know it today
Genes are codes that amino acids follow to come together and form complex proteins. These proteins ensure proper development and regular functioning of an organism. Thus, the basic principle of life, known as the ‘central dogma’ was defined.
Credit: Epigeneticist/ Own work/ https://commons.wikimedia.org/wiki/
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Selective breeding between organisms was recognized as having the potential to facilitate the production of the choicest of off-springs. The whole fuss about ‘wooing’, ‘attraction’, and ‘pheromones’ was so much more justified now!
The 'not-so-pretty' side of the coin
Selective breeding is not devoid of the ugly possibility of genetic codes going wrong. The defective proteins that are generated from the faulty genetic codes disrupt the normal development and functioning of an organism, resulting in debilitating and sometimes life-threatening conditions.
The study, management, and prevention of genetic disorders has made it possible to map, trace, and analyze genes and their expression. Minute aspects of one’s lifestyle can now be connected to the health to their genes, and the likelihood of developing chronic conditions like diabetes, arthritis, cancer, Alzheimer's, the numerus inborn errors of metabolism, and many more can be predicted by genetic analysis.
Better safe than sorry
An entire branch of genetics is dedicated to counselling to-be parents about potential genetic abnormalities in their offspring(s). Genetic disorders are irreversible, and while modern medicine has succeeded in managing and sustaining lives affected by a few of these disorders, the quality of life is often severely compromised and in certain unfortunate cases the lifespan is extremely short. Counselled and informed parents are, therefore, in a better position to take an appropriate decision.
Cut - Copy - Paste
Feats accomplished in research are often akin to science fiction! CRISPR, a fairly recent feat is basically a genetic scissor that can cut and paste genes with pin-point precision to produce ‘designer’ organisms. Some examples of the possibilities with these ‘genetic scissors’ are mosquitoes that produce sterile offspring(s) and the de-extinction of the woolly mammoth.
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