Have you heard of the phrase “it’s all in your genes?” Well, this is how scientists explain the physical characteristics, personality traits, and behaviors which make each and every human being unique. The clues that are carried in our DNA are now used in order to establish criminal guilt or innocence, predict the chance of inheriting a disease or medical condition, determine paternity or maternity questions, and even trace the long-distant ancestors of the human family tree.
The body is made up of tiny units which are referred to as cells. According to some estimates, there are as many as 100 trillion of them in each of us. Within the nucleus of each and every one of these cells is a set of instructions which inform the cell what role it should play in the individual’s body. These instructions come in the form of a molecule called DNA. DNA is short for deoxyribonucleic acid, and it consists of two thread-like strands that are linked together in the shape of a double helix.
DNA is made up four chemical bases:
- Adenine (A)
- Cytosine (C)
- Guanine (G)
- Thymine (T)
It is these bases that are combined into pairs (adenine with thymine and cytosine with guanine) in order to create the “rungs” of the DNA ladder. Rungs, or accurately called base pair, are one of three billion pairs which all work together in order to provide the instructions for building and maintaining a human being. Many letters of the alphabet are combined in order to form words and sentences. The sequence of these bases is the “letters” which spell out the genetic code.
Contained in the nucleus of each cell, there are DNA molecules which are coiled around proteins into tiny structures referred to as chromosomes. Each human cell generally contains 23 pairs of chromosomes, for a total of 46. One chromosome in each pair is inherited from the mother, and the other from the father. Twenty-two of these pairs, which are sometimes referred to as autosomes, look the same in both males and females. The 23rd pair which is referred to as the sex chromosome, because it determines the gender, is the one which differentiates males and females. There are two copies of the X chromosome in females, one from each parent, and one X chromosome in males from their mother, and one Y chromosome from their father. It is the father who determines the sex of his child.
DNA is an extremely intricate subject. The genes in the human body are sections or segments of DNA and it is these that form the individuals units of heredity. These are carried on the chromosomes and contain instructions for making molecules which are referred to as proteins. Each protein enables a cell to perform its very own unique function. The body’s red blood cells contain hemoglobin and it is these that are responsible for transporting oxygen throughout the body. Insulin is another protein that helps the body to metabolize food. The keratin protein is what helps your hair and nails to grow. Imagine DNA as a recipe for creating a living thing, and then remember that genes and proteins are the ingredients which work together to build, repair, and run the human body.
The traits which make each and every one of us unique are also inherited from our ancestors. A person’s physical characteristics such as blue eyes, curly hair, and a tendency for acne are all determined by their genes. It is also believed by scientists that emotional and behavioral traits are also influenced by an individual’s genetic makeup. Such things as intelligence, eating habits, a affinity for aggressiveness, and even sleeping patterns all have their roots in our DNA.
Due to the fact that genes are carried on the chromosomes, two copies of each gene are present in every human being. One is inherited from the mother and one from the father. However, the two copies are not necessarily the same. Genes come in various forms. These variations are known as alleles. Different alleles are what produce variations in inherited traits. For this reason, your individual traits such as hair color or blood type may not match those traits that are contained within the genes of either of your parents.
