What Is A Gene?

Do you ever wonder why you look more like your mother than your father? Do you wish you had a different eye color? Well, those things can't change permanently because you get genes from both parents that determine all of your traits. You can even look quite different than a sibling or quite alike. It all depends on the dominant genes from both parents.

In biology, a gene is a segment of DNA located on chromosomes that produce protein. Genes also exist as alleles of which you need two to produce a certain trait in offspring. You get alleles from both parents that determine your genetic traits.

Within genes are the genetic codes in nucleic acids to produce specific proteins. DNA is not directly transmitted to proteins but is transcribed in a process called DNA transcription. Within the nucleus of your cells is where DNA transcription takes place. Transcription factors are proteins that determine whether a gene is turned on or off. Transcription factors bind to the DNA and determine which genes in a cell are expressed. Your cells have alleles in pairs to make up your genetic composition. You get one allele from each parent that pair together, so you may have blue eyes like your mother or brown eyes like your father.

It is possible to inherit genes form asexual reproduction and sexual reproduction. Asexual reproduction produces organisms that are genetically identical to one parent. Sexual reproduction is when you acquire genes from both the male and female parent to make a distinct new individual. Two brothers born at different times with the same parents will not look identical.

Gene dominance is when genes compete with one another to exhibit traits from either parent. Complete dominance is when one allele for a gene is dominant and turns off the other allele for the gene. Incomplete dominance is when neither gene is dominant over the other and the genetic result is a mixture of both parents. Co-dominance is when a gene contains both alleles for a trait and both are fully expressed.

A gene pool is the collection of all the genes in a population that can be passed down from parents to children in a single species. Populations with more diverse genes make a larger gene pool. The gene pool determines the physical characteristics in the population at any time.

When the sequence of nucleotides in DNA is altered, it is called a genetic mutation. The alterations can affect a single pair of nucleotides or be as large as a segment of a chromosome. Some mutations can result in disease, although others are barely noticeable. You can also get unique traits in this manner such as freckles, dimples or even multicolored eyes.