Each cell in the human body contains roughly about 25,000 to 35,000 genes. These genes carry information that make up a persons traits. Traits are characteristics that you inherit from your parents. Half come from your mother and the other half come from your father. For example, if both of your parents have brown eyes...more then likely you will inherit the trait of brown eyes as well.

An estimated 100,000 genes in the human genome.

A transfer of chromosomes occur upon reproduction from both parents. 23 chromosomes from your mother and 23 from your father make up your chromosomes. In total you have 46 chromosomes that make up who you are as a person. Of these 46, 44 are your chromosomes known as your autosomes. The remaining 2 chromosomes are your sex chromosomes which are commonly known as XX and XY.

Of these sex chromosomes (X and Y), the Y chromosome is much shorter than the X chromosome. Due to this difference in length, there are a number of sex-linked conditions that can occur. One of the most popular sex-linked conditions is known as colorblindness.

The gene found for colorblindness is found in the X chromosome. A women is rarely colorblind because she has the dominant gene for normal vision. Males have shortened Y chromosomes. Therefore, they have no gene to offset a gene for colorblindness. Due to this difference in genes, males are most likely to have colorblindness over a female.

All of these traits: colorblindness, differences in X & Y chromosomes, number of genes within a human genome is what genetics is made of. It was what gives each of us our very own uniqueness and it is the reason that that the study of genetics is very important. As y ou navigate through the rest of this chapter, more information, examples and sample quizes will be avialable to you inorder for you to further understand the human genome.