Dna Biology Review

Today, we are learning the language in which God created life.

(President Bill Clinton, 26 June 2000 announcing the first draft sequence of the human genome)


The basic unit of life is the cell, which is a miniature factory producing the raw materials, energy, and waste removal capabilities necessary to sustain life. Thousands of different proteins, called enzymes, are required to keep these cellular factories operational. An average human being is composed of approximately 100 trillion cells, all of which originated from a single cell. Each cell contains the same genetic programming. Within the nucleus of our cells is a chemical substance known as DNA that contains the informational code for replicating the cell and constructing the needed enzymes. Because the DNA resides in the nucleus of the cell, it is often referred to as nuclear DNA. (As will be discussed in Chapter 10, some minor extranuclear DNA exists in human mitochondria, which are the cellular powerhouses.)

Deoxyribonucleic acid, or DNA, is sometimes referred to as our genetic blueprint because it stores the information necessary for passing down genetic attributes to future generations. Residing in every cell of our body (with the exception of red blood cells, which lack nuclei), DNA provides a 'computer program' that determines our physical features and many other attributes. The complete set of instructions for making an organism, i.e., the entire DNA in a cell, is referred to collectively as its genome.

DNA has two primary purposes: (1) to make copies of itself so cells can divide and carry on the same information; and (2) to carry instructions on how to make proteins so cells can build the machinery of life. Information encoded within the DNA structure itself is passed on from generation to generation with one-half of a person's DNA information coming from their mother and one-half coming from their father.

Stuttering Simple Techniques to Help Control Your Stutter

Stuttering Simple Techniques to Help Control Your Stutter

Discover Simple Techniques to Help Control Your Stutter. Stuttering is annoying and embarrassing. If you or a member of your family stutters, you already know the impact it can have on your everyday life. Stuttering interferes with communication, and can make social situations very difficult. It can even be harmful to your school or business life.

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