Human Genetics

Human genetics is the study of the human genome. The basics of this study lies within the DNA strand at the chromosome level where there are 46 different chromosomes arranged in 23 pairs. When the chromosomes are laid out in a pattern it is known as a karyotype. The karyotype is like a map of your DNA or your human genetics. One of the easiest pairs of chromosomes to examine are the X-Y chromosomes. If you have two X chromosomes, you are female. If you have two Y chromosomes, you are male.

Each chromosome is made up of paired strands of DNA that twist and form a helix that resembles a twisted ladder. These helixes are coiled and wrapped up tightly into the shape we see in a karyotype. Each strand of DNA is made up of nucleotides. There are four nucleotides, A (adenine), C (cytosine), G (guanine), and T (thymine). Each one is always found with its pairing nucleotide - A to T and G to C. The bonds between them form the rungs of the helix ladder. The differences between the sequences of the DNA nucleotides is what makes one person different from another person.

A genetic mutation occurs when a normal sequence of DNA nucleotides is changed in some way. All DNA strands have mutations and most go unnoticed. A few are bothersome (such as an extra toe) but are harmless. However, some genetic mutations can cause a great deal of health problems or even death. When a genetic mutation is suspected to be the cause of a health problem (such as Down's Syndrome), DNA testing is performed. Down's Syndrome results from trisomy 13, meaning that the person has 3 number 13 chromosomes, instead of only two.

Some genetic mutations are beneficial. For example, some people are naturally resistant to certain illnesses. If genetic scientists can determine the gene responsible for this resistance, it could lead to a time when all people could be genetically altered to be resistant to the disease. The study of human genetics is vital to our continued survival. Without this field and technological advances new threats like the avian bird flu and others could wipe out the human race.

Human genetics is a growing field and more money is being spent every day to try to use the human genome to advance our quality to life. Although the basic building blocks have been uncovered and studied at the most minute level, there is still much to learn about how genetics structures who we are.