How Many Genes are Present in The Human Body

Introduction

Human body contains about 20000 to 25000 genes, of which every gene has two copies, one inherited from each parent. A gene is the functional unit of heredity. Genes are the instruction manual for the synthesis of proteins. Genes can have different sizes ranging from a few hundred bases to some million bases in size. Most genes are the same in people but approximately 1 percent are a bit different between people, which results in all the differences in humans that we see. There are over 200 different cell types in our body, and all these interpret our information very differently, in order to keep us alive.

How scientists identify different genes

Scientists name different genes by unique names to differentiate between the genes, they can also use some symbols, which can be a unique combination of numbers or alphabets, which represent an abbreviated version of gene name. For example, a gene associated with chromosome 7, related to cystic fibrosis bears the name as cystic fibrosis transmembrane conductance regulator, with its symbol being CFTR.

Not all genes have been found till now, even after 21 years (as of 2022) from the initial publication of the human genome.

What are Actually Genes Made Up of

A gene is a small portion of DNA, and DNA is made up of a combination of millions of small bases, which come in 4 types namely A (Adenine), C (Cytosine),T (Thymine) and G (Guanine). Our body has 3,000,000,000 bases and the entire combination of these bases or sequence of genes is called our genome.

How genes encode protein

Basically genes are some longer sequences of DNA, which when transcribed gets converted into RNA, which after translation creates protein, which then gets folded uniquely to give protein their unique functions, which can then be used accordingly. Proteins perform various functions like giving energy to the muscles, giving colour to the eye pigments, making hair or fingernails, etc.

What are Chromosomes

Tightly wound coils of DNA are called chromosomes, they are found inside the cells, we have 23 pairs of chromosomes in each cell, which amounts to 46 chromosomes per cell.

What is the Source of Genes

We inherit our genes from our parents, we can see it in our day to day experiences like, children having similar features as their parents, we receive half of our genetic material from our mummy, and other half from our daddy, we get two versions of each gene, and the more dominant one gets expressed .

For e.g. the gene for brown eyes is more dominant over the gene for blue eyes, thus, if a child has both a blue eye gene and a brown gene, the child will be having brown eyes.

Only twins have the same genome and the other siblings will have different genes.

Is There any Role of Nature or is it all Genes

Our environment also has a huge impact on how our body will look, whether we would be able to utilize our full potential or not (which is a result of having good genes).

For e.g. we may inherit genes for being tall from our parents, but if our diet is poor, then we won't be able to fully utilise our potential and thus, we may end up being stunted.

We can see the role of environment in the identical twins, as their bodies have the same genes and thus, any difference is due to the difference in the environment that they were a part of.

Conclusions

Without correct genes our body cannot function, and we may die due to some genetic disorder or variation, but if this same variant is supported by natural selection, then it may help them in evolving, which is how newer species develop.