Genetics & Heredity- Erakina

Introduction

• How many times have we been looked at by long-lost relatives and heard them say, “This one looks so much like her dad!” or heard them fawn over one-month-old babies, saying, “This one has her mother’s nose and father’s eyes”? 
• These similarities that we get pointed out and about are what we inherit from our ancestors and family members from generations preceding. Science calls this phenomenon ‘heredity’.
• Additionally, the study of features and character traits that we inherit in heredity is what science calls ‘genetics’. 
• But these scientific terms cannot be simply defined in such laymen terms.
• To understand genetics and heredity, these scientific terms need to be broken down into simplicity, while retaining their true meaning and reasoning – which is what the following sections will be all about.
• But, before breaking down heredity and genetics, it is important that we first know the common thread between them – Gregor Mendel.

Gregor Mendel – A Pillar Of Modern Biology

• Born in 1822, Gregor Mendel was a staunch Augustinian monk. Augustinians are members of the Christian religion following the Law of Saint Augustine, written about 400 AD by Augustine of Hippo. 
• However, despite being a  monk who believed in the religious way of life, he had many questions about living creatures that he knew only science could answer. Some of his rising queries were ‘where do human beings come from?’, ‘what if human beings didn’t come from where science says we do?’ and hereby the ultimate question ‘In what aspects would human beings turn out different if human beings didn’t quintessentially come from where we usually do?’.
• Mendel knew that his Bible would give him some answer to these queries, but he wasn’t looking for just some answer. He was looking for a solution, which his religious monk mind initially thought was easiest through science. Little did he know then.
• As a first step, Mendel thought of a plant-based experiment to answer his questions. 
• What he did was simply crossbreed pea plants with different characteristics.
• The observations from this experiment led to laws regarding the transmission of heredity characteristics from generation to generation.
• Many of the concepts that Mendel worked out from these observations led to some very important laws of genetics and heredity that hold even today. They are famously called ‘Mendel’s Laws. 
• Well, now that we know about Gregor Mendel and his queries which were answered over a long period of experimenting and research, we can easily grab the concepts of genetics and heredity in the following sections.

Heredity – Definition & Contribution

• Heredity is primarily defined as the passing on of one trait from one generation to the next through sexual reproduction and sexual reproduction.
• This definition is fundamentally backed by the understanding of a very important fact that not all traits are passed onto offspring and not all traits that the offspring get are from their immediate previous generation – their parents. 
• Now, these traits and characteristics are stored as what we call ‘genes’ – a very important component of the DNA. Performing as the carrier of genes, DNA poses as a self-replicating biological material.
• This is the reasoning behind offspring appearing and behaving only somewhat similar to their parents and previous ancestors, which means that offspring receive a shuffled collection of genes.
• Another reason behind offspring not being exact replicas of their ancestors in all aspects yet also being somewhat the same is the changes in the structure of DNA during and after reproduction due to various intrinsic factors. 
• Additionally, with the advancement of molecular biology, the biggest contribution of heredity to mankind is finally being understood with the help of various biological tools and techniques – the origin of mankind from cellular reproduction. 

DNA 

A gene

Genetics – Definition & Contribution

• Genetics is primarily defined as the study of heredity. But, of course, genetics cannot be just that because the type of study involved is equivalent to that of the entire field of biology – never static and always evolving.
• Truest to the nature of science, genetics is a very vast, challenging, and limitless field of study for a biological aspect as crucial to human existence as heredity.
• Genetics is all about understanding the mechanisms that control an offspring’s appearance from genetic information, how genes are expressed, interactions between genes, gene expression from one animal to another, character traits and their genes, etc.
• Geneticists, people who study genetics,  have thus developed ideas and tools for studying genetic engineering. 
• Today, geneticists are capable of decoding the entire DNA composition of any individual in just a few days. This advancement has served to be one of the most promising scientific ones for mankind as it now enables doctors to identify genetic diseases even at the embryonic periods of offspring.
• These diseases are then cured with gene therapy, as they get detected at a very early and non-life-threatening stage in offspring.
• The study of genetics has enabled mankind to not just analyze the generation in which a particular hereditary disease in an individual began but also predict the probability of which generation this disease will occur in the individual’s future. 

By – Daya Atreya

 10-01-22