Chromosomal DNA is packaged inside microscopic nuclei with the help of histones. These are positively-charged proteins that strongly adhere to negatively-charged DNA and form complexes called nucleosomes. Each nuclesome is composed of DNA wound 1.65 times around eight histone proteins.

Today, DNA identity testing is widely used in the field of forensics and paternity identification. Finally, DNA identity testing can be used to evaluate tumor transmission after transplantation and thus determine whether a malignancy is of donor or recipient origin.

DNA is pivotal to our growth, reproduction, and health. It contains the instructions necessary for your cells to produce proteins that affect many different processes and functions in your body. Because DNA is so important, damage or mutations can sometimes contribute to the development of disease.

DNA contains the instructions needed for an organism to develop, survive and reproduce. To carry out these functions, DNA sequences must be converted into messages that can be used to produce proteins, which are the complex molecules that do most of the work in our bodies.

Key Concepts and Summary. DNA serves two important cellular functions: It is the genetic material passed from parent to offspring and it serves as the information to direct and regulate the construction of the proteins necessary for the cell to perform all of its functions.

DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.

Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups. Attached to each sugar is one of four bases–adenine (A), cytosine (C), guanine (G), or thymine (T).

In turn, each nucleotide is itself made up of three primary components: a nitrogen-containing region known as a nitrogenous base, a carbon-based sugar molecule called deoxyribose, and a phosphorus-containing region known as a phosphate group attached to the sugar molecule (Figure 1).

Five nucleobases—adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U)—are called primary or canonical. They function as the fundamental units of the genetic code, with the bases A, G, C, and T being found in DNA while A, G, C, and U are found in RNA.

A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Some genes act as instructions to make molecules called proteins.

Despite the rumors, urine is not a sterile substance. It naturally contains bacteria that renders it a nonsterile substance. While the bacterial levels are likely low, it’s important to understand the implications of drinking urine, either for your health or survival.