Genetics is the field of study that is concerned with heredity and the numerous variations in organisms. This includes DNA, genes and chromosomes which are the three main sub-topics within genetics and are related to each other in a unique way.
Deoxyribonucleic acid also known as DNA is the hereditary material in humans and almost all other organisms which contain the biological instructions that make each species unique. DNA is inherited from a person’s mother and father and it therefore passes genetic information from one generation to the next. It is also made up of a long chain of simple units called nucleotides, with a backbone comprised of sugars and phosphate atoms made by ester bonds. This DNA is mainly located in the cell nucleus as well as the mitochondria in that specific cell.
Furthermore, the structure of the DNA is also extremely important in the study of genetics. It is mainly consisted of sugar molecules, phosphate molecules, and nitrogen bases in the form of a double helix. The backbone of this double helix is made up of alternating segments of sugar and phosphate molecules. This is also described as two strands running in opposite directions with each chain made up of a polymer of simple sub-units called nucleotides. There are four different types of nucleotides which join the two backbones and stem from the sugar molecules and are given one letter abbreviations. This includes A for adenine, G for guanine, C for cytosine and T for thymine.
However, these bases known as distinct amino acids can only pair specifically with one another and is called complementary base pairs. These bases will only bind with its certain counterparts and only occurs when DNA is replicated, and the transcription and translation of RNA. In complementary base pairing, only A will bind with T, and G will bind with C. During the transcription of RNA, Thymine (T) is replaced by Uracil (U), which only binds with A.
Next, genes are made of DNA, and so is simply a certain combination of an organism’s DNA that formed traits within generations. These working sub-units consist of enough DNA to code for one protein and act as instructions to make molecules into those proteins. Every person has two copies of genes, one from their father and one from their mother. What makes genes vary from one another is the alleles which have a slightly different sequence of DNA bases and this contributes to each unique physical feature of a person.
These genes are also extremely important to us and are responsible for many duties. Not only do they produce the proteins that run our bodies, they carry messages that can determine how long we can live, what disease we suffer, what sex we will be and how we function as an individual. It also decides our physical appearance like the colour of our eyes and our hair or the shape of our nose. That is why children resemble their parents in one way or another due to the passing down of genes through generations.
In addition, transcription is the synthesis of RNA under the direction of DNA. Through this, DNA turns into RNA which in turn constructs protein although RNA is less stable than DNA due to the extra oxygen in the molecule. RNA polymerase first binds to a region of DNA called the promoter region where it pries the two strands of DNA apart. These two strands are called the coding strand and the non-coding strand. The RNA polymerase binds to the coding strand of the DNA and begins to produce mRNA. Finally, when the RNA polymerase is finished, mRNA leaves and is either modified or immediately used to construct proteins.
As the strands of genes and DNA increase in length into threads, they become chromosomes. Chromosomes are thread-like structures located inside the nucleus of animal and plant cells and like DNA and genes, determine the characteristics and traits of one’s physical appearance. Chromosomes are also singular pieces of DNA which contains genes and other nucleotide…