MORE ON GENES
[In response to “I am interested to know more on the intricacies behind genes”.- Cdr V Krishnan]
Well, a few things need to be clarified, if non-biologists seek to understand ‘Genes’ and their activity in life-be it humans or for others. In all ‘live’ systems ‘genes’ determine the profile of that system-one celled or more celled. Even non-cellular organizations like ‘VIRUSES’ regulate their hosts using the viral genes. Incidentally, the term ‘gene’ has become viral in social settings due to a wide ranging cluster of medical information using the name ‘gene’. It simply boils down to the idea that genes are fundamental to biological activity - resulting in form, shape, growth , physiology, reproduction of all living systems. Literally, everything of every living thing is a gene product resulting in ‘features’ typical to that life form.
To understand the whole idea, certain conditions must be accepted as ‘Determinants’. Most of the biological structures are ‘Proteins’. The common belief that ‘PROTEINS’ are essential for health should not interfere with the information that biological structures are proteins and need not cause any confusion. Yes, there are many proteins- like Hair proteins, Muscle proteins, Skin proteins etc, etc., each subtly different from other proteins. Together they make our physical ORGANIZATION besides taking care of all functions. So, there are two components for a life -in the form of a] Structure, b] Function. As such, these two are taken care of by proteins of 2 kinds- a] structural proteins and b] functional proteins. Either of them is a gene product. Both these products are determined by the genes in that organism. This means that the genes express themselves in appropriate places in the body of the individual. Only then the plant or animal resembles its kind even after several generations. So, the fidelity of a plant or animal requires the right gene to ‘speak’ its way. This ability of the gene is named ‘Gene Expression’. Gene expression obeys two components like space and time [ where and when]. Imagine -hair growth genes express themselves all over, humans would be like monkeys. So, every structure should reveal itself in its normal place [space] and at the appropriate age [time]. As evidence, we may cite change of voice among boys from earlier soft to later heavy and coarse, growth of beard; likewise, physical features among girls signify gene-mediated changes in structure of humans.
While structural proteins involve in building the physical form, fidelity is maintained to that of the race and to that of parentage. Parentage may extend beyond that of immediate generation into the earlier ones of Grand Parents. That is why we hear of instances of some children bearing resemblance to grandma or grandpa, besides in certain other features of their parents. The grand ma, grand pa has a wider spread-- In the sense that there are maternal and paternal sides to everyone, even if we may not have seen them. But, those who have seen those persons readily recall how a child has a striking resemblance to his/her Grand Parent[s]. This means what? The members of those elder generations are dead but their genes keep travelling through their children. In this travel through successive generations, some new gene combinations arise by ‘mixing’ of different gene forms associated with a human structural feature. Such a mixing of ‘traits’ is considered a healthy improvement for better survival. By the same set of reasons of mixing of bad genes through ‘within the fold’ marriages, defective off spring can arise and they generally have low survival value. Marital combinations among unrelated members can offer the natural advantage of unrelated gene pools, so that bad genes [double defects] may not get into one child and express congenital disorders. The issue holds a lot more to understand of gene functioning in biological systems. Most features have 2 sets of gene [1 each from either parent] . One or both of them may be equally strong [dominant ] or one strong and the other weak [recessive] For recessive genes to express their feature, a double dose [2 recessives] is needed. If it happens, bad /weak traits like incomplete growth, deformities, mental retardation and the like occur. Chances of the 2 recessive genes coming together may be enhanced by marital combinations within the family. Chances for the origin of congenital disorders from different gene pools coming together [among unrelated people] in expressing recessive feature is rather low.
More to follow
Prof. K. Raman
We have been taught about Genes during our post graduate course only. Only after coming to teaching line we come to know the details of the structure and functions of genes.
ReplyDeleteGenes are segments of nucleic acids. Along with protein , nucleic acid form chromosome.
You can not miss any biological material without protein. They function as structural proteins like formation of tissues and organs.
They help in transport of digestive particles and wastes from one place to another. They help to protect our body by the formation of antibodies.
They help in our body movement by contractile proteins.
They help as messengers
by carrying hormones from one organ to another organ.
They also help in digestion of many products.
It is funny to know that proteins play the vital roles in our body, their synthesis is controlled by genes.
It’s a basic thing that females have two XX chromosomes and males have oneX and one Y chromosomes. This Y chromosome has male sex determining gene.
A married couple may not have a male child for that the wife was blamed and leading to divorce. But scientifically the husband is to be blamed for not contributing his Y chromosome in the process of fertilisation .
Now in biology the basic taxonomy , & embryology subjects are neglected and more detailed studies are given importance to genes. In the post graduate level subjects like genetic engineering,Biotechnology and Genomics have been introduced.
What we learnt in our PG course as a drop has become a ocean now.
K.Venkataraman