Genomics and Cloning

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Author: Farid Ahmed

Genetic engineering and cloning play a vital role in today’s competitive technological and scientific advancements. The techniques of genetic engineering are advanced versions of the ancient practice of selective breeding.

Nowadays, genetic engineering and cloning are continuously making headlines in media around the world. While many view them as new sciences, these technologies actually have a long and rich history. For thousands of years, humans have used various genetic and scientific techniques. In ancient times, when early humans noticed particular traits in domesticated animals, they would select those animals for breeding in the next generation. Gradually—sometimes over hundreds of years—people observed that specific traits were passed onto the next generations. This process was later named “Selective Breeding.” Through selective breeding, humans were able to domesticate wild animals and achieved great success in agriculture.

Early humans sparked the first instance of ‘selective breeding’ by preserving traits in sheep and other animals and, in a way, altering their genes. Today, this selective breeding process has become much more scientific and strategic. Through it, livestock such as cattle, buffaloes, goats, and more are produced for farming.

The most fascinating thing is that, initially, it was not easy to understand whether this remarkable technique of genetic engineering actually worked. But now, researchers comprehend this process and have provided scientific explanations. Gregor Mendel was the first to introduce the concept of genetics, and in explaining this process, he showed that hereditary traits are influenced by certain tiny entities—what we now call “atoms of inheritance,” or genes.

We know that all living creatures are made up of cells. Some organisms consist of just a single cell, while others are composed of billions. Although all cells are not identical, similar principles and production mechanisms are involved in their formation. Similar patterns and production times can be seen across living species. Even the slightest variation in these mechanisms has led to the diversity and origin of all life forms on our planet.

Hidden within almost every cell of the human body is a tiny machine. Every functional unit, called a cell, holds within itself all the information of the human body. From bone structure to the form of hands and feet, and determination of the brain—everything in the body’s trillions of cells is regulated by this intricate system of cells.

To sustain life, thousands of “organs” or “cells” are constantly being connected within our bodies every moment. Oxygen enters with the air we inhale, nourishing and maintaining all the trillions of cells. Meanwhile, blood circulation acts like a hydraulic motor, facilitating the communication between different organs.

Surprisingly, every organ is relentlessly performing its specific function every moment without conscious direction from us. The body carries out these preplanned functions on its own.

The signals that direct all this growth and activity are found in the human genome. It is the genome that instructs the cells to perform vital life and chemical activities.

Within the human genome lies the fundamental blueprint of humanity. In order to protect life from destruction, different parts coordinate their functions. Observations in our lives are important because these differences determine our success. To guide the next generation correctly, we must make firm resolutions.

Each part of the human genome exists due to the precise distinction of structures called genes. Differences in these genes make each human unique. Each genome is composed of an ensemble of cells. All genomes instruct cells, helping them perform their functions properly.

Genomes are not exclusive to humans; every living organism has a genome—fish, birds, trees—all have their own genomes. Humans may not fully understand the significance of these organized systems within, but inherently, we carry this guidance within our hearts. Science explores these great truths, and through realization, anatomy finds unity.

The resemblance and relationship between all living animals and plants, as well as their components, tie the ancient heritage of life together on Earth. For instance, the bodies of all creatures and their ancient ancestors are fundamentally similar; the only differences in their genomes are determined by certain chemical entities. These chemical entities constitute one essential component known as “Deoxyribonucleic acid,” or DNA.

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Even a hundred years ago, very few people accepted the idea that perhaps a single molecule could hold the instructions for all activities in a living creature. But in reality, that is exactly what the DNA molecule does. Within the nucleus of the cell are tiny structures known as chromosomes. Scientists knew from early on that chromosomes were involved in cellular activities. However, it took them a long time to understand how DNA actually worked.

Figure 2: Position of DNA inside the chromosome

Chromosomes are very small, thread-like structures found in the cell’s central nucleus. From the day of their discovery, it was observed that they are composed of woven strands, built from DNA. The other structural units, arranged in sequence, are called nucleotides. DNA, genes, and nucleotides are all components of the genome. The essential materials combine with this basic structure to form the complete genome.

A simple way to understand the whole genome and its parts is to think of it as a book or a ledger. Like a book divided into chapters, these chapters are made of paragraphs, and paragraphs are made of words, which in turn are made of letters. Except for red blood cells and directly related cells, every cell in the human body holds a complete “book.” This “book” is the human genome.

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Like chapters, paragraphs, and words form the structure of a book, every cell—except red blood cells and a few closely related types—contains the entire “text”. This “text” or book is, in fact, the human genome.

Red blood cells do not have a nucleus and thus lack DNA. While all other major cells in the body have a complete set of DNA, the absence in red blood cells isn’t unusual. Red blood cells transport oxygen within the body, acting as biological “gas trucks.” As a result, they are actively involved in carrying carbon dioxide out. This is a vital part of the body’s essential operations. Their lack of a nucleus allows red blood cells to maximize their capacity for aerobic function.

Just like a book needs a structure and backbone for stability, chromosomes play the backbone role in the human genome. Chromosomes connect everything and hold everything together, organizing and maintaining the genome’s integrity through condensation and arrangement.

One easy way to understand a human genome is to compare it with nucleotides, linking specific distinctions and, to generalize, connecting them by forming a link through chromosomes. The genome can carry out specific isolated functions. Simply put, one part of the human body is made up of tiny chromosomes; another is maintained by the energy of nucleotide molecules and cells throughout the body.

Nucleotides don’t all look the same, which introduces some complexity. Their functions are not always identical and can be entirely different. However, most perform their tasks reliably, working like components in a larger sequence, much like how nucleotide arrangements determine the structure and function of chromosomes. Some chromosomes aggregate information to control cellular activities, while others control physical traits such as eye and hair color.

The entries in an encyclopedia are written on paper; in the genomics encyclopedia, the DNA molecule can be compared to paper. On this “paper” are written “letters” and “words” that instruct life how to form and function correctly. These “paragraphs” are genes.

Genes tell cells what to do. Just as a paragraph gives a specific instruction to a piece of text, a gene instructs a cell to take on a particular shape or perform a function. Like grains of sand that form a rock and gradually turn to dust by erosion, genes change and shape over time, affecting all of life’s processes.

Words are formed by letters, and in the same way, genes are made up of nucleotides. As an example, the word “stand” is made up of a sequence of letters. Change just a few and the meaning is transformed. Similarly, altering the sequence of nucleotides in a gene can profoundly change a cell’s function and, by extension, fundamentally alter the processes of life.

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