An Introduction to Genetics

By Narayani Shankar

What is Genetics?

Genetics, the study of genes and heredity, is a field that seems to be rapidly advancing in science. So, what exactly is genetics? Well, this field explores the inheritance of traits, the variation of organisms, and molecular processes behind these.

DNA:

At the core of genetics is a very important molecule called DNA, or deoxyribonucleic acid. DNA is the molecule that encodes genetic instructions. Shaped like a double helix(or a twisted ladder), DNA is composed of nucleotides, each containing a sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). These four bases together make up strands of DNA.

Genes:

Genes are specific sequences or strands of DNA that usually encode for proteins. Proteins are like the workers of the cells, managing processes ranging from metabolism to structure. The sequence of nucleotides in a gene determines the sequence of amino acids in a protein, which therefore influences an organism's traits.

The study of genetics allows us to understand how traits are passed from one generation to the next. Genes come in pairs, with one copy inherited from each parent. Alleles are different versions of a gene, and they can be dominant or recessive. Dominant alleles mask the effects of recessive alleles in heterozygous individuals, giving rise to diverse traits within populations.

Mendelian Genetics:

Gregor Mendel, the father of modern genetics, formulated the laws of inheritance in the 19th century. His experiments with pea plants showed principles like segregation (where alleles segregate during gamete formation) and independent assortment (where genes on different chromosomes assort independently during meiosis). These laws laid the foundation for our understanding of genetic inheritance.