What are genes?

Genes are the instructions for making human bodies, including the machines inside the body's cells. Different genes determine different things about the body, like hair and eye color, and height and build. People get genes from their parents, one set from their mother and one set from their father. That's why most people look a bit like their mother and a bit like their father.

Genes are like recipes, they're instructions to build something. Both mom and dad contribute a copy of their entire recipe book to their offspring, but for many genes, only one copy of each recipe will be used by the baby. Mom and dad have exactly the same recipes (one for eye color, one for hair color, one for quantity of nostril hair, and so on) except they may have slightly different versions of those recipes (they're called alleles).

Given the fact that virtually every person in this world looks different than every other, the nearly infinite possible combinations of maternal and paternal DNA are what give us our individuality. When maternal brown eyes and maternal red hair gets paired with paternal blue eyes and paternal blond hair, there are four possible combinations for offspring. Brown eyes/blond hair, brown eyes/red hair, blue eyes/blond hair, blue eyes/red hair.

Extrapolate that scenario out to 23 chromosomes and the possible combinations become mind-boggling, about 8.3 million combinations—meaning that there's about a 1 in 8 million chance that the same mother and the same father would have two kids with the exact same coding (excluding identical twins).

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Genes are the DNA segments within chromosomes that carry genetic information and control the transmission and expression of one or more traits. They direct your cells to create the proteins that run the biochemical reactions of your bodies. There are an estimated 70,000 genes within the genome.

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Genes are the biological units of heredity. Genes determine obvious traits, such as hair and eye color, as well as more subtle characteristics, such as the ability of the blood to carry oxygen. Complex characteristics, such as physical strength, may be shaped by the interaction of a number of different genes along with environmental influences.

Genes are located on chromosomes inside cells and are made of deoxyribonucleic acid (DNA), which is a type of biological molecule. Humans have between 30,000 and 40,000 genes. Genes carry the instructions that allow cells to produce specific proteins, such as enzymes.

To make proteins, a cell must first copy the information stored in genes into another type of biological molecule called ribonucleic acid (RNA). The cell's protein synthesizing machinery then decodes the information in the RNA to manufacture specific proteins. Only certain genes in a cell are active at any given moment. As cells mature, many genes become permanently inactive. The pattern of active and inactive genes in a cell and the resulting protein composition determine what kind of cell it is and what it can and cannot do. Flaws in genes can result in disease.

The answer is based on source information from the National Cancer Institute.

Genes are more than what you wear, they make us what we are. We are all created from two sets of genetic blueprints, strings of amino acids (the basic building blocks that make up deoxyribonucleic acid [DNA]) that tell our cells what proteins to produce in order to make our bodies work. One set of chromosomes comes from your mother and one set comes from your father.

Our genes make us unique. If we all had the same genetic make-up, we would all be identical twins—we would all be the same sex, the same race, the same everything. Luckily, the genes from our parents combine to form a unique mixture which determines everything from our eye and hair color to, in some cases, whether we will be susceptible to certain diseases.

Genes are the basic units of deoxyribonucleic acid (DNA) that provide instructions to our body. Our genes are housed on chromosomes (structures in our cells that contain our genetic information). Although the same set of genes is contained in most of the cells of our body, a particular gene may only play a role in a certain part of the body (for example, the heart). Genes are a series of letters (A, C, G, and T) and are involved in the production of proteins. Proteins perform a variety of functions in our body. If there is a change in the letter sequence of a gene (called a mutation), the protein may not be made or may not work properly.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.