Have you ever wondered how and why physical characteristics such as your mom’s red hair, grandma’s freckles or some family member’s skin cancer is passed on from one generation to the next? The answer lies hidden in your DNA, which is your own unique genetic code.

Your unique genetic code

Human genetics is the study of genes and inheritance, that is all those family traits, physical features and even diseases common to your family that pop up in every new generation.

To understand human genetics you need to know something about cells, chromosomes and DNA.

Your body contains millions and millions of different cells, for example muscle cells, blood cells and skin cells. The nucleus or control centre of each cell contains all your genetic information: whether you have straight or curly hair, are right or left-handed, your body shape, what type of metabolism you have, etc. This information is carried in structures called chromosomes.

There are 46 chromosomes in the form of 23 pairs in every cell. Each pair with the exception of the 23rd pair is identical and contains one chromosome inherited from your mother and one from your father. The 23rd pair, the sex chromosomes, is different. This pair contains either two copies of the X chromosome if you are female or an X and a Y chromosome if you are male.

Chromosomes are made up of long strands of a chemical called deoxyribonucleic acid, also called DNA. Part of the genetic information in your DNA is organised into thousands of specific coded instructions called genes. Your DNA and genes contain all the information that helped to make you the unique individual you are.

Genetics and everyday life

The study of genes (genetics) has many every-day advantages such as:

    • Helping you understand why people look the way they do.
    • Helping doctors understand why some people are more prone to certain diseases than others. A famous example is the case of Queen Victoria of England who was a carrier of the blood disease haemophilia in which spontaneous bleeding occurred and couldn’t be stopped because the blood would not clot. One of her grandchildren, the young son of the Tsar of Russia inherited this disease from his mother as did others of her extended family.
    • Helping parents with a family history of common genetic conditions and diseases to understand their risk of passing it on to their children but also providing the means to test and identify these conditions in babies before they are born.
    • Helping to develop targeted medicines for certain diseases. After studying a patient’s genetic profile doctors can now help predict whether that person will respond to certain medications or not.
    • Helping researchers to explore how genes are influenced by the environment. This field of study is called epigenetics. The environment, that is anything to which the body is exposed including stress, diet, drugs, exercise, bacteria, UV sunlight, home and workplace hazards, toxins, etc, will often determine whether your inherited, genetic disposition to a disease or condition will manifest or not.
    • Helping to catch criminals by using genetic fingerprinting techniques. For example hair follicles, blood or skin cells can determine an individual’s presence at a crime scene.

Some controversial issues regarding DNA are still being hotly debated by both proposers and opposers. These include cloning of animals and people and genetically modifying certain foodstuffs!

Do your genes determine your entire life?

Yes and no! Despite the fact that you do indeed inherit your DNA and the genetic code that determines certain of your unique characteristics, epigenetics claim that you can biologically modify (“switch on” or “switch off”) the way your genes work by changing your environment. They claim that by understanding your DNA you can modify your genetic predisposition or tendency, for example to cancer, Alzheimer’s disease, heart disease, obesity and many other conditions that may run in your family. You are still the author of your own life and, genetically speaking, you have the immense power to choose to change your environment and how you live!

 

Sources

Genetics in everyday life. Retrieved from: https://www2.le.ac.uk/…everyday-life…/Script%20for%20Genetics%20in…
Rosenthal, L. 2014. How to outsmart your genes and live a better life. Retrieved from: http://www.huffingtonpost.com/lillie-rosenthal/how-to-outsmart-your-gene_b_5368693.html
Where DNA meets daily life. Retrieved from:  http://www.hsph.harvard.edu/news/magazine/genetics-environment-cancer/