We live in a world which is largely driven by and invariably reliant on science and technology, yet the vast majority of the people hardly know anything about advancements in science and technology. Each one of us may have his/her own field of speciality, but that does not exclude or excuse anyone from acquiring basic knowledge about the things that affect our lives. This knowledge gap has given impetus to the growing threats of anti-science zealotry, which has seemingly become an entrenched problem in our society, both in the developed and developing world.

But without scientific knowledge and technological advancements, humanity wouldn’t have been able to triumph over many of the challenges which confronted us some decades ago. Certainly, our hope for the future also lies in science and technology. The failure of any group of people to recognize this simple obvious reality is only a display of hypocrisy at its apogee.  

Bringing this home, one thing is certain from the onset of the debate on genetically modified organisms (GMOs) in Ghana; the GMO opposition continues to wage a war of propaganda instead of rationale arguments on the core subject under contention. These anti-science zealots know vividly that, a rational discourse on the subject would not yield the results they want. So instead, they have adopted the cunning and devious strategy of some of our current world politicians, by endlessly appealing to the emotions and sentiments of the general public in order to win their support. For instance, the anti GMO movements very often attack our work as scientists with emotionally charged arguments to the effect that we are only pretending to work for humanity, or are only satisfying our own egos, or are working merely for the profits of industry. Recognizing the great influence the media wield in society, they continue to trumpet this argument in lieu of the core issues on the various media platforms.

In fact, rationale arguments succeed in influencing only a small minority of the public-at-large in our country, even with the help of the media. I, for one, take heartfelt umbrage against this irrational and unscientific trend of decision making in our beloved nation. Obviously, we don’t need a prophet of doom to predict the dire consequences of our choices, if this trend should continue unchecked.  We can all see the results of such bad choices around us.

As the debate on GMOs and the technology for producing those rages on, the few privileged scientists in this field of study must rise to the call as a national duty to clarify, educate and instill confidence in the populace without sounding too technical. So far, the swift response of some of my colleagues has been very encouraging and enlightening in this regard, and we must continue to inundate our nation with fundamental knowledge of the science behind the technology for producing GMOs in a way that, those without a basic background knowledge in biology may comprehend what we seek to communicate.

This article therefore seeks to unequivocally communicate meaningful scientific knowledge about the science of genetic engineering or modern biotechnology in a language slightly different from the way it is taught in the classroom to students. As the late Norman E. Borlaug (Nobel Prize Laureate for Peace, 1970) stated in 2000, “one of the great challenges facing society in the 21st century will be a renewal and broadening of scientific education at all age levels that keeps pace with the times. Nowhere is it more important for knowledge to confront fear born of ignorance than in the production of food, still the basic human activity. In particular, we need to close the biological science knowledge gap in the affluent societies now thoroughly urban and removed from any tangible relationship to the land. The needless confrontation of consumers against the use of transgenic crop technology in Europe and elsewhere might have been avoided had more people received a better education about genetic diversity and variation”.

Before I proceed, it must be stressed that genetic modification or engineering of crops is not some kind of Whiteman’s witchcraft, rather, it is the progressive harnessing of the forces of nature to the benefit of the human race. As it would be demonstrated in this article, it is not unnatural as the opponents of the technology more often assert. I will endeavor in this article to make the reader appreciate the ingenuity of man, as we observed Mother Nature to develop the science of genetic engineering or modern biotechnology for the benefit of humanity.

At this point, I am urging the reader not to be dispirited or wane in enthusiasm by the many terminologies used in this article. Albert Einstein (awarded Nobel Prize in Physics, 1921) once made the submission that, “everything must be made as simple as possible, but not simpler”. I have thus, clearly and painstakingly explained all biology jargons in simple everyday English that is comprehensible to all. Where necessary, I have provided analogies and examples to aid understanding of the various biological concepts. In most cases, the author has used human related examples, to help the reader to quickly grasp these fundamental concepts.

Natural life as we know it

Biology, the science of life, for centuries has sought to gain insight into the various forms of natural life. But let’s pause for a second and ask, what is life, or what kinds of things constitute life? Well, to begin with, you and I are alive, our families, friends and neighbors are also alive, and so are the plants and animals we see around us. Life is all around us. From gigantic whales and elephants, to tiny unseen microbes or germs that crawl around on your computer keyboard or in your palms, mouth or stomach.

Biology is the science of learning about every kind of life, regardless of where it is, or how big or small it is. For centuries, biologists have gained tremendous insight into the relationships between the various life forms on our planet. Outwardly, one can easily distinguish between plants, animals and humans, based on some visually observable characteristics. However, beyond these observable features differentiating the various life forms we see around us, there is a great deal of similarity which can only be observed at the molecular or sub-cellular level of life. Although, the plant life is different from the animal life and human life superficially, at the molecular level, the chemical basis for these various life forms is universally the same more or less.

So, at this point, one might ask, what is the chemical basis of all natural life forms? Before I attempt to deal with this important question, it is fundamentally imperative to lay the foundation of molecular biology, or life at the sub-cellular level. In this regard, it is essential to make mention of the first dictum one would ever learn in biology, which is the cell, where all important life processes occur.

The cell is the smallest and basic structural unit of any living organism, which is capable of independent functioning, and holds the recipe for building a whole system of the organism with its differentiated and specialized tissues and organs. Now let’s break this ascribed definition down using a more familiar analogy, as all truth is parallel.

You are part of a very large and complex world as a single individual. At the family level, you work together with other members of your family to do house chores, like cleaning your home, setting the table, making dinner, and many more. Other families in addition to your family in your locality constitute a community. To achieve a common interest in your locality such as neighborhood watch or cleanup, your family works in coordination and cooperation with other families to carry out such important tasks. Your locality is in turn part of a larger city or region, which is also part of a nation, and finally our nation is part of the greater international community. Thus, from one single individual to an entire planet, filled with human beings and other animate and inanimate things, where each entity has a specific role to play. Some of us have specialized as farmers, teachers, medical doctors, builders, engineers, journalists, and other specialties. All of these various professions work in unison to achieve a common goal; improving livelihoods, preserving our planet and making it a better place to live for the present and unborn generation.

Biologists observe a similar organization as described above, as we delve into the bodies of living things. Inside any living thing, cells are the basic intricate component one would see. Cells are like people in the analogy above. Each cell is an independent entity performing a specific function. In a human body for instance, instead of a farmer, some cells might assume the responsibility of digesting food to release their nutrients; or instead of medical doctors, cells might be assigned the responsibility of fighting diseases or infections that enter the body to keep it healthy, etc.

There are living organisms that consist of only one cell numerically, so they are termed unicellular, whereas those that consist of more than one cell are called multi-cellular. In multi-cellular higher organisms like plants, animals and humans, a family of cells that live very close together and perform the same function become a tissue, and many different tissues in turn come together to constitute what biologists refer to as an organ. This is tantamount to a city in the analogy above. Different organs work together to form a system in order to play a greater role.  Similarly, different systems come together to form the complete organism or lifeform. Thus, natural life is organized into cells, tissues, organs, systems, whole organism, and population of individuals.

Interestingly, in multi-cellular organisms like plants, animals and humans, which numerically consist of billions of cells, which differ from each other in terms of function, size, shape, etc., all the cells originated from just one single cell. That is, one single cell produced all the billions of cell you are made up of today, isn’t it wonderful?  Based on this profound fact, one would not be wrong to theorize that, cells therefore grow in size, increase in number by dividing or splitting, and undergo differentiation (change in form) to generate the various tissues, organs and systems as explained above. This is what biologists term the cell theory!

Put differently, in humans for instance, a single cell (the zygote) produced your bones, muscles, heart, liver, kidney, brain, blood, skin, hair, etc.  This ability or capacity of a single cell or group of cells to grow, proliferate and regenerate all previously missing or absent tissues and organs to form a complete individual is referred to as potency by biologists. Generally, plant cells are more potent than animal cells. This is the main reason why, if a branch of a growing plant is removed, the plant can regenerate (re-grow) the part that was removed to make it complete again, unlike an animal or human, where an amputated limb or damaged organ may never regenerate (“may” because I still believe in miracles!). However, current knowledge in biology shows that we can virtually make all cells to be as potent as the original single cell (zygote) that produced all the other tissues and organs. This basic discovery is very profound and has very great and unimaginable applications.

With this basic knowledge, one shouldn’t be overly astonished to hear scientists say in the very near future that, they can now replace a damaged human organ with a new “flesh and blood” natural one. This is what regenerative medicine is all about! In other words, this is the industry that will produce natural human spare parts! I am aware that, this is too big for others to accept, especially some religious folks! We must not forget that, this has been made possible by observing what Mother Nature does.

Inside the cells of living organisms: genomes and genes

So far, we have established that, the billions of cells with varied functions you or any multicellular organism is made up of emanated from a single cell.  An obvious question would then be how are these billions of cells in the body produced by just a single cell? In other words, what is the written code or manual or program or recipe for building an entire organism from a single cell? To answer this question, it is imperative we dig deeper into what cells are constituted of, in order to understand how they perform their various functions.

 Every cell is equipped with its own machinery like a factory, referred to as organelles (small organs), which it uses to carry out its assigned function. At the center of each cell of higher organisms, is a special compartment, called nucleus, which controls and coordinates activities in the cell. That is, the nucleus determines at any point in time, the state of each cell. Inside the nucleus, are some physical structures that hold the information or program or instructions that dictate what goes on in the cells in any given time. These physical structures in the nucleus that bear the manual or code for building natural life are called chromosomes by biologists.

The number of chromosomes present in the nucleus varies between different species of organisms and also the type of cell within any particular species. In multicellular organisms that perpetuate themselves through sexual reproduction, we can categorize the cells in their bodies into two basic types, based on the number of chromosomes contained in their nucleus. These two cell types are somatic (body) cells and germ cells. The main difference between a somatic cell and a germ cell is that, the latter contains half the number of chromosomes present in the former. The germ cells are only found in the sexual reproductive organs of sexually reproducing organisms, and they are produced when the organism reaches reproductive maturity (puberty for humans). All other cells besides the germ cells in the reproductive organs constitute somatic cells. The germ cells further develop to become the gametes (reproductive or sex cells), which are the cells involved in sexual reproduction.

In humans for instance, there are 46 chromosomes in each somatic cell of a normal human being, hence there are 23 chromosomes in each human germ or gametic cell (i.e. half of the number present in the somatic cell). Thus, each human sex cell (sperm for males, and egg for females) contains 23 chromosomes. Based on this insight, we can say that there are two sets of 23 chromosomes (23 + 23) in each somatic cell of a human being, and one set of 23 chromosomes in a germ cell, termed as diploid and haploid sets respectively. This haploid set of 23 chromosomes in a human germ cell is referred to as the human genome. All other living organisms also have their own genomes, made up of the haploid set of chromosomes in their germ cells. As another example, the crop plant, rice, has 24 chromosomes in its somatic cell (i.e. two sets of 12 chromosomes, 12 + 12), hence the genome of rice consists of 12 chromosomes (equal to the number of chromosomes in its germ cell or half the number in its somatic cell).

The genome of any living organism can therefore be viewed as, a repository of the complete set of information or instructions or manual or programs for building and maintaining an entire living form of that organisms. At this point, one can easily visualize the chromosomes constituting a genome, as the physical tablets (plaque or slab) on which this biological instructions or recipes for building life have been inscribed. In other words, the recipe for making humans can be found in the human genome, and similarly, the recipe or manual for making any other living organism can be found in the genome of that organism.

In nature, likes always beget likes and dislikes of the same kind. In other words, cats always give birth to cats, dogs always beget dogs and humans always reproduce humans, but all cats, dogs or humans don’t look alike. That is, by nature, all humans for example have the nature of humans, but by inherited traits (hereditary factors), we can observe distinctive features among all humans. For example, considering sex (gender), skin color, nose shape, height, body weight, eye color, hair color, intelligence, blood group, etc., as common inherited traits, we can observe differences among a population of human beings. These characteristics are inherited from parents through sexual reproduction.

Put differently, there are hereditary factors which control the inheritance of these traits from parents to their children. These hereditary factors are called genes by biologists. Based on this understanding, we can define a gene as a unit of inheritance. Thus, there are underlying genes controlling the inheritance of the various traits mentioned above and all other traits not mentioned. So, what is the relationship or connection between genes and chromosomes? It is very simple, chromosomes are made up of genes!

The branch of biology that studies genes is genetics. Genetics is therefore concerned with how genes function, their structure, inheritance, differences, among others in living organisms. Geneticists (scientists that study genetics) try to find the underlying genes that control or determine differences in an observable feature in an organism. So, there are those who major or focus solely on human genetics, animal genetics or plant genetics, but the underlying principles are the same regardless of where one specializes.

DNA and the fantastic four

So far, our journey into the genomes of living organisms has been terrific and informative. Let’s now go deeper into the sub-cellular level to discuss the chemical basis of genes. As mentioned above, all natural life on the planet is built based on a written code or program or manual or instruction or recipe inscribed on chromosomes, which are situated in the nucleus of cells. We have also learnt that the complete recipe or program for building each lifeform on the planet constitutes the organism’s genome. So, each genome can be viewed as a book containing the instructions for building the plant life or animal life or human life. This therefore implies that there is a language used by the designer to write these books of genomes that spell out the program for building each life.

This language is called the DNA language, and it is the same language the designer used to write all the various genomes of life. DNA language is therefore the universal language of natural life! From the early 1950s till date, biologists have been studying the DNA language to decipher the secrets to natural life. Our understanding of the DNA language has equipped us with the tools of modern biotechnology of which genetic engineering is considered the most powerful and controversial.

DNA (standing for Deoxyribonucleic acid) is a helix-shaped macro-molecule, which is found on chromosomes. First, DNA is a chemical but its chemical structure encodes the written program or recipe for building all natural life. Just like the English language makes up words and sentences using 26 alphabets to express an idea or thought, the DNA language uses just four letters (A, C, G, T, and G) to clearly encode the instructions for building a whole organism. These four letters are what I’ve nicknamed above as the Fantastic Four. The DNA language is therefore a sequence of these four letters (like ATGAAACCGGTTTAAA……) and a word in DNA language is represented by a combination of the four letters in groups of three (such as ATG, AAA, CCG, etc.). A word in DNA language is termed codon. Biologists have been able to develop a lexicon for the DNA language based on these triplet codes or codons, and it is referred to as the Genetic Code. Compared to an English language dictionary, the genetic code is far simpler, in that there are only 64 words with their corresponding meanings.

DNA can virtually be obtained from any part of your body, because it is found in every cell in you. There is DNA in your hair, bones, blood, muscles and anything that originates from you, including your saliva, sweat, etc. Your DNA is genetic signature, hence unique, but it is the same DNA that would be found in all cell types in your body. This is the basis of forensic science in relation to crime and civil law.

Today, scientists have sequenced the entire genome of certain species of organisms, hence we know the approximate number of letters of A, C, G, and T each genome is composed of and the order in which they are arranged on the chromosomes. For instance, the human genome consists of 3 billion letters of A, C, G, and T, the rice genome is about 400 million letters, maize is about 2.5 billion letters, and wheat is about 16 billion letters of A, C, G, and T. All of these were accomplished in the last decade. It cost US$ 3 billion to sequence the entire human genome, which lasted for more than a decade to completion, but today it costs less than US$1000 to sequence a human genome in less than a week.

Origin of genetic variation and diversity in nature