JOIN USWhat makes you 'you'?
Have you heard about Dolly the sheep? She was a sheep like no other — she was a clone of another sheep. This means that her DNA was identical in every way to that of the original sheep. Of course, this didn’t happen naturally. You may be like one of your parents but its next to impossible for you to be exactly like them. Dolly was created through a remarkable job that we call genetic engineering. A good idea? Well, let’s consider that a little bit later. For now, let’s focus on the marvel that we call genes.
Our bodies are made up of billions of tiny cells and these tiny cells have even tinier structures (that look a bit like strings of noodles) inside their nuclei and these are called chromosomes. Chromosomes are found in pairs of 23. One half of the pairs comes from your mom and the other half from your dad. The chromosomes are made up of DNA (deoxyribonucleic acid) and about 2% of this DNA make up what we call genes. Can you imagine how tiny they are? And yet, they play such an important part in making us who we are. Do you have thick, black, straight hair like your mom? That’s because of the genes. Or maybe you’re tall and have long legs like dad — the genes again. Your genes are the bosses that instruct your body on how you should be. We have approximately 30,000 genes, and these can be found in every cell. Genetics is the study of how genes work and pass on traits.
Almost 200 years ago, an Austrian monk named Gregor Mendel first studied how traits are passed on from one pea plant to another. Nobody realised at the time that the very same process is how humans also pass on their traits.
A part of our DNA isn’t really human. Aliens? Well, maybe not quite so interesting. They are from viruses that have accumulated in our bodies over the course of evolution. So that means if one of us had the coronavirus, there’s a tiny chance that a great, great, great grandchild of ours will carry a minuscule bit of that virus unknowingly. We share 25% of our DNA with grandparents so by the time we go down a few generations, this will become 1/8 and then 1/16 and so on. Your dad has 2 genes for a particular character, one from his mom and one from his dad. But you are going to inherit only one of them. The same goes for your mom. This is how endless variations are possible even among siblings.
Since only 2% of the DNA is the actual genetic material, we have for a long time, labelled the rest of the DNA ‘junk DNA’ but scientists are beginning to think that that is not quite true. It’s just that we don’t know enough yet.
We share 98.7% of our DNA with monkeys (ha… ha…) and 77% with a gelatinous creature that lives amidst seaweed and is called the star ascidian (ugh). Why, 40-50% of our DNA is the same as that of the cabbage! We could so easily have become some other creature but luckily, we have something called ‘control genes’, which make us human and not cabbage.
Every time a cell in our body divides (and this happens quite often in certain organs like the stomach lining, for example), the entire DNA duplicates itself. There are very rarely mistakes in this copying process but they do happen occasionally and then you have an exceptional human — maybe someone who has super hearing or super vision or something. Spider-Man could be a mutation that we all know. Of course, sometimes, the mutations aren’t as much fun. Scientists now believe that it may be mutations that cause certain illnesses like cancer. Mutations are also responsible for things like albinism where the gene that controls the colouring function doesn’t work properly and people end up without colour in their hair or skin.
Genetic engineering is when the DNA of an organism is altered in a lab. This could be by changing a pair, deleting a part or adding a bit. Some important products like human insulin and hepatitis B vaccine have been made through this method.
But there is some controversy over genetic engineering and fears that it may be misused. What if someone made an exact clone of themselves for not-so-good reasons?