A Short Explanation of Genes and Chromosomes

Chromosomes are the building blocks of genetics. They are extremely important, for they house our genes. Nuclear DNA, which makes up most of the DNA in our bodies, is bound together by chromosomes. Everything about our genetic makeup is determined by these elements, and as such, when one understands how these work, it's unbelievable how many things we can understand about how people look, act, and how they are made.

All of our chromosomes, save our sex chromosomes, occur in pairs. Humans in particular have 23, whereas some species of plants have thousands. The first 22 chromosomal pairs are considered autosomal, whereas the twenty third pair is our sex chromosomes, which are extremely important for inheritance and sex-linked traits such as color-blindness.

In general, genes are incredibly important - they are strains of DNA that have some sort of function in our bodies. These observable functions or traits are called phenotypes, as opposed to the genotypes, which is the description of the genes that produce these traits. An example of a phenotype, for instance, is hair color. A genotype for hair color could be AA, with A being the allele that codes for brown hair.

Interestingly enough, some DNA strains are what are commonly referred to as "junk DNA". These are also referred to as introns. Functional sections of these strains are known as exons. When RNA is formed, these introns are discarded and only the exons are bonded to make the molecule. For this reason, if a mutation occurs on an intron in DNA, it has absolutely no effect, since this portion is discarded in the replication process.

Genes also regulate the processes that our bodies undergo. Take puberty for an example. Why is it that this doesn't occur until the early teen years? It is because regulatory genes literally turn the genes that activate this process on. Another example is the hemoglobin molecule. While we are born with both adult and infant hemoglobin producers, the infant producer is turned off by regulatory genes.