Category Archives: DNA

In molecular biology, the term double helix[1] refers to the structure formed by double-stranded molecules of nucleic acids such as DNA. The double helical structure of a nucleic acid complex arises as a consequence of its secondary structure, and is a fundamental component in determining its tertiary structure. The term entered popular culture with the publication in 1968 of The Double Helix: A Personal Account of the Discovery of the Structure of DNA, by James Watson. The DNA double helix polymer of nucleic acid, held together by nucleotides which base pair together.[2] In B-DNA, the most common double helical structure found in nature, the double helix is right-handed with about 1010.5 base pairs per turn.[3] This translates into about 20-21 nucleotides per turn. The double helix structure of DNA contains a major groove and minor groove. In B-DNA the major groove is wider than the minor groove.[2] Given the difference in widths of the major groove and minor groove, many proteins which bind to B-DNA do so through the wider major groove.[4] The double-helix model of DNA structure was first published in the journal Nature by James D. Watson and Francis Crick in 1953,[5] (X,Y,Z coordinates in 1954[6]) based upon … Continue reading →

DDC Memorial Blood Center Minneapolis and St Paul, Minnesota DNA Testing Services in Minnesota: AABB Certified Immigration Testing DDC Memorial Blood Center is an AABB accredited laboratory that can coordinate all DNA sample collections regardless of location. For immigration testing, there are guidelines issued by the US Department of State and AABB that require an AABB laboratory to coordinate the entire DNA testing process. DDC Memorial Blood Center offers a variety of testing options for every situation: Legal Test: Legally Admissible Results Home Paternity Test: Strictly for Peace of Mind Prenatal Test: Non-Invasive Prenatal DNA Testing DDC Memorial Blood Center is proud to offer the most convenient DNA paternity testing locations in Minneapolis and surrounding areas. DDC Memorial Blood Center is the world's most trusted DNA paternity testing laboratory. Since 1995 we have offered the highest quality DNA testing at affordable prices. Schedule your appointment today by calling one of our consultants at 612-871-6636 - we'll arrange sample collection at a location most convenient for you. The rest is here: Name in DNA Testing - DNA Diagnostics Center … Continue reading →

Isabel Rojas Identity is an interesting concept. For the most part we like to believe that we define our own identity. The truth is a lot goes into defining our identity. And what it comes down to is what we accept as our own. The more we know about ourselves, our own experiences, our families past and heritage, and so on - the more our own identity changes and evolves and becomes further defined in our minds and accepted as our own. I have a lot of thoughts and experiences around this topic that have caused my own identity do grow and evolve over time. Here is a snap shot: I was born in NYC, the youngest of 5 kids. My parents and three older siblings were born in Bogota, Colombia. My family migrated to NYC in the late 70s looking for a better life. After my brother and I were born in the early 80s my parents had begun to realize what a dangerous city it was at that time and decided to head back to Colombia. They worked hard to build a 3 story building where we would live, work, and rent out space. It was a 3 … Continue reading →

Alternate Titles: deoxyribonucleic acid DNA, abbreviation of deoxyribonucleic acid, organic chemical of complex molecular structure that is found in all prokaryotic and eukaryotic cells and in many viruses. DNA codes genetic information for the transmission of inherited traits. A brief treatment of DNA follows. For full treatment, see genetics: DNA and the genetic code. The chemical DNA was first discovered in 1869, but its role in genetic inheritance was not demonstrated until 1943. In 1953 James Watson and Francis Crick determined that the structure of DNA is a double-helix polymer, a spiral consisting of two DNA strands wound around each other. Each strand is composed of a long chain of monomer nucleotides. The nucleotide of DNA consists of a deoxyribose sugar molecule to which is attached a phosphate group and one of four nitrogenous bases: two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). The nucleotides are joined together by covalent bonds between the phosphate of one nucleotide and the sugar of the next, forming a phosphate-sugar backbone from which the nitrogenous bases protrude. One strand is held to another by hydrogen bonds between the bases; the sequencing of this bonding is specifici.e., adenine bonds only with thymine, … Continue reading →

DNA damage resulting in multiple broken chromosomes DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many as 1 million individual molecular lesions per cell per day.[1] Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages (interstrand crosslinks or ICLs).[2][3] The rate of DNA repair is dependent on many factors, including the cell type, the age of the cell, and the extracellular environment. A cell that has accumulated a large amount of DNA damage, or one that no longer effectively … Continue reading →

Latest Articles The world-renowned geneticist scrutinizes ancient DNA for clues to the earliest chapters in the human story. By CARL ZIMMER The project poses ethical issues about whether humans could be created without parents. By ANDREW POLLACK Dr. Mukherjee, the author of the Pulitzer Prize-winning cancer book The Emperor of All Maladies, explores the history of genetic discovery. By JENNIFER SENIOR A Barnard professor writes, Multiple studies over the last decade have already shown that the misattribution of paternity is rare. Genetic engineering may emerge as an important tool to avert extinctions. But ecosystems are complex, and this tinkering might not unfold as planned. By HILLARY ROSNER Most of the diversity outlined on the new tree has been hiding in plain sight. By CARL ZIMMER Scientists hope to find answers in the DNA of people who have a mutated gene that should have made them ill or killed them, but did not. By GINA KOLATA In frank statements, the Most Rev. Justin Welby, the spiritual leader of 86 million Anglicans, and his mother talked of the shock of discovering the truth in the past month. By YONETTE JOSEPH A number of recent genetic studies challenge the notion that mistaken paternity … Continue reading →

A-DNA is one of the possible double helical structures which DNA can adopt. A-DNA is thought to be one of three biologically active double helical structures along with B-DNA and Z-DNA. It is a right-handed double helix fairly similar to the more common B-DNA form, but with a shorter, more compact helical structure whose base pairs are not perpendicular to the helix-axis as in B-DNA. It was discovered by Rosalind Franklin, who also named the A and B forms. She showed that DNA is driven into the A form when under dehydrating conditions. Such conditions are commonly used in to form crystals, and many DNA crystal structures are in the A form. The same helical conformation occurs in double-stranded RNAs, and in DNA-RNA hybrid double helices. A-DNA is fairly similar to B-DNA given that it is a right-handed double helix with major and minor grooves. However, as shown in the comparison table below, there is a slight increase in the number of base pairs (bp) per turn (resulting in a smaller twist angle), and smaller rise per base pair (making A-DNA 20-25% shorter than B-DNA). The major groove of A-DNA is deep and narrow, while the minor groove is wide … Continue reading →

Jude Thaddeus Augustus Powers 950 N STATE ST STE A HEMET, CA Kathlyn Julia Bloom-Rudibaugh 901 S STATE ST STE 100 HEMET, CA Barrie Marie Robinson Courthouse Plaza, 910 N State St Ste B Hemet, CA Laurence Elgin Peterson 43493 Dodaro Dr Temecula, CA Joyce Elaine Fleming 29995 Technology Dr #101 Murrieta, CA Paul Aaron Levine 910 N State St Hemet, CA Charles Scott Rudibaugh 901 S STATE ST STE 100 HEMET, CA Quinton Ray Swanson 800 E Florida Ave Suite 250 Hemet, CA Priya Darshini Navaratnasingham 29995 Technology Dr Ste 301 Murrieta, CA James Lillard 27393 Ynez Rd Temecula, CA People in California shared their opinions about Paternity Testing Do you personally know of anyone who has undergone paternity/maternity testing? Yes: 57% No: 37% Unsure: 4% Have you undergone paternity or maternity testing? Yes: 20% No: 77% Rather not say: 1% What was the reason that you underwent paternity/maternity testing? Ordered by the court to prove I was/was not the parent: 23% For my own proof that I was/was not the parent: 25% To prove to the mother/father/child that I was/was not the parent: 26% Other: 17% Rather not say: 7% Have any of your immediate family members ever … Continue reading →

Deoxyribonucleic Acid (DNA) We all know that elephants only give birth to little elephants, giraffes to giraffes, dogs to dogs and so on for every type of living creature. But why is this so? The answer lies in a molecule called deoxyribonucleic acid (DNA), which contains the biological instructions that make each species unique. DNA, along with the instructions it contains, is passed from adult organisms to their offspring during reproduction. Top of page In organisms called eukaryotes, DNA is found inside a special area of the cell called the nucleus. Because the cell is very small, and because organisms have many DNA molecules per cell, each DNA molecule must be tightly packaged. This packaged form of the DNA is called a chromosome. During DNA replication, DNA unwinds so it can be copied. At other times in the cell cycle, DNA also unwinds so that its instructions can be used to make proteins and for other biological processes. But during cell division, DNA is in its compact chromosome form to enable transfer to new cells. Researchers refer to DNA found in the cell's nucleus as nuclear DNA. An organism's complete set of nuclear DNA is called its genome. Besides the … Continue reading →

Deoxyribonucleic Acid (DNA) We all know that elephants only give birth to little elephants, giraffes to giraffes, dogs to dogs and so on for every type of living creature. But why is this so? The answer lies in a molecule called deoxyribonucleic acid (DNA), which contains the biological instructions that make each species unique. DNA, along with the instructions it contains, is passed from adult organisms to their offspring during reproduction. Top of page In organisms called eukaryotes, DNA is found inside a special area of the cell called the nucleus. Because the cell is very small, and because organisms have many DNA molecules per cell, each DNA molecule must be tightly packaged. This packaged form of the DNA is called a chromosome. During DNA replication, DNA unwinds so it can be copied. At other times in the cell cycle, DNA also unwinds so that its instructions can be used to make proteins and for other biological processes. But during cell division, DNA is in its compact chromosome form to enable transfer to new cells. Researchers refer to DNA found in the cell's nucleus as nuclear DNA. An organism's complete set of nuclear DNA is called its genome. Besides the … Continue reading →