Humans are made up of trillions of cells — small units that control the functions of our body. Each cell is made up of organelles, which you can see in the diagram below. Each organelle in a cell is much more complicated than the diagram suggests. Let’s zoom into the part responsible for coordinating activities in the cell: the nucleus!
The nucleus contains the genetic information of the cell in the chromatin fibers. This information is stored in the form of DNA or Deoxyribonucleic Acid.
Think of our genetic information as a long scroll of instructions for our body. In each cell, this coil measures around six feet long! The instructions dictated by DNA are responsible for such things as our eye colour, foot size and our ability to role our tongue or not!
Our DNA is unique because each person has a different sequence of bases. The bases A (adenine), C (cytosine), T (thymine), and G (guanine) are repeated in different orders, generating different patterns, and code for proteins which perform a variety of functions in our bodies.
What kind of functions? Some base sequences cause the protein hemoglobin to be manufactured. This is the component of our blood that transports and transfers oxygen. Other base sequences may generate proteins like actin or myosin, responsible for muscle contractions. Our body simply wouldn’t function without the proteins that our base sequences create!
Ever wondered what a gene is? It is a stretch of DNA that codes for a specific protein. Look at the diagram below to see how our genes dictate the proteins made in our body!
So what happens if something goes slightly wrong in the code? Perhaps you have heard of people whose bodies lack the ability to clot blood. This condition is called hemophilia, a disorder caused by a mutation or mistake in the base sequence of DNA. Suppose that the base ‘A’ is meant to be used in a protein, but instead the base ‘T’ is used. This will change the protein created and may cause a disorder in the body. Genetic testing has become a popular way of testing unborn babies or fetuses for genetic disorders, or even adults who are experiencing health complications. By sending your cells to a laboratory, scientists are able to analyze the base sequence of your DNA for possible disorders.
Interested in other genetic disorders? Research sickle cell anemia, Huntington’s disease or Down’s syndrome, and let us know what you find!
Written and illustrated by Rya Sara Jetha. Rya lives in Mumbai, India with her family. She enjoys writing, playing the piano, running and baking.