Genetics 101
Genetics is a highly complex subject covering many disciplines, but by understanding some basic terms you will be able to easily understand your report. Our reports are consumer friendly, but just in case we have compiled a list of common terms to help you.
Understanding The Importance Of Your DNA
Every one of the seven billion plus humans on earth is unique. No two individuals are physically identical, have the exact same personalities, nor the same preferences. What is unique is every individual’s DNA. Even though 99.9% of the world’s population share the same genetic makeup, the 0.1% that is different between individuals is immensely significant. This one tenth of one percent determines a wide range of traits covering everything from how likely it is to develop a degenerative disease, to how strong an individual’s craving is for sweets.
Cells
A cell is the basic building block of living things. An adult human body is estimated to contain between 10 and 100 trillion cells.
Nucleus
The Nucleus is the portion of the cell that contains the majority of the cell’s genetic material.
Genes
A gene is the basic physical unit of inheritance. Genes are passed from parents to offspring and contain the necessary information to specify traits. Humans have approximately 20,000 genes arranged on their chromosomes.
Chromosomes
A chromosome is an organised package of DNA found in the nucleus of the cell. Different organisms have different numbers of chromosomes. Humans have 23 pairs of chromosomes, 22 pairs of numbered chromosomes (called autosomes), and one pair of sex chromosomes (X and Y). Each parent contributes one chromosome to each pair so that offspring get half of their chromosomes from their mother and half from their father.
DNA
DNA, which is short for deoxyribonucleic acid, is the molecule that carries genetic instructions in all living things. The DNA molecule consists of two strands that wind around one another to form a shape known as a double helix. DNA is comprised of four nucleotides which you may recall from biology class. These four nucleotides are adenine (A), cytosine (C), guanine (G), and thymine (T).
SNP (Commonly Pronounced As Snip)
Single nucleotide polymorphisms (SNPs) are a type of polymorphism that are responsible for many of the differences in individuals. Polymorphism is simply a scientific term indicating that there are potential differences between individuals. These differences are commonly referred to as variants. In the human genome these variants correlate to everything from what is the best diet to eat, to how certain medications will work, and how likely an individual is to develop certain illnesses.
Allele
An allele is one of two or more versions of a gene. An individual inherits two alleles for each gene, one from each parent. If the two alleles are the same, the individual is homozygous for that gene. If the alleles are different, the individual is heterozygous.
RNA
RNA, which is short for ribonucleic acid, is another amolecule found in cells and provides a wide range of functions extending from communicating instructions at a cellular level to aiding in creating the proteins required for cellular growth and reproduction.
Genotype
A genotype is an individual’s collection of genes. The genotype is expressed when the information encoded in the DNA of the cell is used to make protein and RNA molecules. The physical expression of the genotype contributes to the individual’s observable traits – this in turn is called the phenotype.
Recap
Working from the largest component to the smallest, here is how all the aforementioned information ties together.
Cell (contains a nucleus) ‐ > Chromosomes (contained within the nucleus) ‐> DNA (make up the chromosomes) ‐> Gene (a specific section of DNA) ‐> SNP (a specific nucleotide within the gene)