DNA is an abbreviation for deoxyribonucleic acid. The shape of DNA is a double helix and all living things are made up of DNA. Friedrich Miescher first isolated DNA in 1869. The only cells in the human body that do not contain DNA are red blood cells. If all the DNA in the human body were unwound, it would reach to the moon and back six thousand times. A single cell can contain six to nine feet of DNA. All humans share about ninety-nine percent of the same DNA sequence. It’s the remaining one tenth of a percent that makes us each unique. We all share a considerable amount of DNA with many other species. Our DNA is ninety-eight percent the same as chimpanzees’ and even fifty percent the same as bananas!
DNA makes up our genes. DNA can be affected by the environment and as a result, environmental factors may result in certain genes expressing or not expressing themselves. In fact, it’s believed that the majority of our genes do not express themselves. It takes about eight hours for a cell to copy its DNA. This copy process must occur before cells divide. Each inch of DNA can store twenty-five gigabytes of information. An entire sequence of DNA is known as a genome. A complete map of the human genome was finished in 2003. Mutations are changes in the DNA sequence and can be caused by exposure to things such as radiation or chemicals. These mutations may lead to an increased risk of disease including cancer. All of DNA’s functions depend on proteins.
All living things today contain DNA which contains our genetic material. This may not have always been the case though. There is a theory that RNA used to serve the function of DNA in the earliest life forms on earth. It is difficult if not impossible to prove this theory, however, since DNA exposed to the environment survives less than one million years.
The study of DNA has numerous scientific applications. DNA testing can determine if crops are authentic or if certain gourmet foods such as caviar and wine are authentic. DNA testing can also help determine a person’s risk for certain genetic diseases. Paternity tests make use of DNA to determine if a father and child’s DNA make-up are sufficiently similar. Similar tests are available to identify sibling or grandparent relationships. Modern-day forensics also relies heavily on DNA testing to determine if someone was present at a crime scene. It can also help to identify victims of crimes or accidents. The techniques that have been used to study DNA led to the development of string search algorithms which Internet search engines use. Genetic engineering can be used to create desirable qualities in offspring, such as crops that are disease-resistant. Genetic engineering is controversial, particularly when it applies to humans. Some opponents worry that people will abuse the technology available and create a “super race”.