What are genes?

In order to have a more comprehensive understanding of genes lets start small and work towards greater complexity. The smallest units of genes are nucleic acids. More specifically genes are made of deoxyribonucleic acids (DNA). DNA is a double helical structure (shown to the left) made up of a combination of 4 different bases held together by a phosphate backbone. The four bases are adenine, guanine, cytosine, and thymine. All life stems from these four bases and the complexity of life stems from the complex arrangements of these four bases. When DNA is in its double stranded form the bases pair up, adenine pairs with thymine and cytosine with guanine. This double stranded DNA forms its own secondary structures in the nucleus of the cell. The secondary structure is usually that of a chromosome.

We know that DNA is the basis for life, but are our nuclei just filled with random arrangements of DNA? Nothing in life is that simple. In order to achieve the complexity of life we need complex arrangements of DNA that can ultimately encode for proteins. This is were genes come in. According to the Webster Dictionary a gene is a specific sequence of nucleotides in DNA or RNA that is located in the germ plasm usually on a chromosome and that is the functional unit of inheritance controlling the transmission and expression of one or more traits by specifying the structure of a particular polypeptide and especially a protein or controlling the function of other genetic material. Essentially this means that a gene is a sequence of DNA that encodes a protein that is needed for life. Recent advances in molecular biology have led to the understanding that a gene can actually encode for more than one protein depending on the conditions the organism is in.