peperonity.net
Welcome, guest. You are not logged in.
Log in or join for free!
 
Stay logged in
Forgot login details?

Login
Stay logged in

For free!
Get started!

Text page


factsb4u.peperonity.net

DNA FACTS

DNA IS The material inside the nucleus of cells that carries genetic information. The scientific name for DNA is deoxyribonucleic acid, the strands of life...

Right before the Ice Age there were three human-like species. One of the three was upright and bipedal but looked more like an ape. The second group resembled what we would refer to as cavemen. They had more apelike skulls and much smaller brains than we have today. The third is us. The Ice Age left a measly 2000 humans and wiped out the other two adaptations completely.
The ancestors of those who stayed-put in Africa are called the Vasikela Kung tribe. From Africa some people migrated to Asia (70,000 years ago). And the some 45,000 years ago some went towards Europe. Humans trekked from Asia across the Bering Straight and into Alaska about 25,000 years ago.
Scientists have taken DNA from the farthest reaches of humanity. They found that everyone shares some of their DNA with the Vasikela Kung. Even today you can see distinct features from all around the globe in the faces of the tribe. Their skin color is such that it can become light or dark depending on the environment.

DNA Facts:

Deoxyribonucleic Acid (DNA), genetic material of all cellular organisms and most viruses. DNA carries the information needed to direct protein synthesis and replication. Protein synthesis is the production of the proteins needed by the cell or virus for its activities and development. Replication is the process by which DNA copies itself for each descendant cell or virus, passing on the information needed for protein synthesis. In most cellular organisms, DNA is organized on chromosomes located in the nucleus of the cell.

A molecule of DNA consists of two chains, strands composed of a large number of chemical compounds, called nucleotides, linked together to form a chain. These chains are arranged like a ladder that has been twisted into the shape of a winding staircase, called a double helix. Each nucleotide consists of three units: a sugar molecule called deoxyribose, a phosphate group, and one of four different nitrogen-containing compounds called bases. The four bases are adenine (abbreviated A), guanine (G), thymine (T), and cytosine (C). The deoxyribose molecule occupies the center position in the nucleotide, flanked by a phosphate group on one side and a base on the other. The phosphate group of each nucleotide is also linked to the deoxyribose of the adjacent nucleotide in the chain. These linked deoxyribose-phosphate subunits form the parallel side rails of the ladder. The bases face inward toward each other, forming the rungs of the ladder.

The nucleotides in one DNA strand have a specific association with the corresponding nucleotides in the other DNA strand. Because of the chemical affinity of the bases, nucleotides containing adenine are always paired with nucleotides containing thymine, and nucleotides containing cytosine are always paired with nucleotides containing guanine. The complementary bases are joined to each other by weak chemical bonds called hydrogen bonds.

In 1953 American biochemist James D. Watson and British biophysicist Francis Crick published the first description of the structure of DNA. Their model proved to be so important for the understanding of protein synthesis, DNA replication, and mutation that they were awarded the 1962 Nobel Prize for physiology or medicine for their work.

• A simple list of the bases of the entire DNA in your genes—the As, Cs, Ts, and Gs—would fill about 200 New York City phone books. That’s about 3 billion letters.

• In 1985, when the Human Genome Project was first proposed, many critics thought it was absurd. At the time, the technology did not even exist to decode the sequence of a simple bacterium, much less a human being.

• While the number of base pairs—3.2 billion—on each unique person’s 23 chromosomes is quite impressive, the average human being has a mere 31,000 genes. That’s about a third fewer genes than anyone expected—and not even double the amount of genes a roundworm has. A variety of amoeba has nearly 200 times as many genes as humans do.

• Any two unrelated strangers anywhere on the planet share 99.9 percent of the same DNA. A miniscule fraction of the genome—about 3 million of its over 3 billion bases—accounts for the vast differences within the human race.

• Genomically speaking, all races are equal. In other words, you cannot tell simply by looking at someone’s DNA whether they are black or white.

• Human beings have roughly 99.1 percent of our genes in common with the chimpanzee, our closest relative on earth. The overlap between mice and humans is surprisingly close, too. We have nearly 75 percent of our genes in common.

• Single gene errors account for more than 4,000 known hereditable diseases, and the list is growing rapidly. A person’s risk for diseases from cystic fibrosis to Huntington’s now can be determined by looking at the DNA.

• The largest human gene is on the X chromosome—the dystrophin gene. Dystrophin is one of the key proteins involved in building strong muscle tissue. Boys born with a mutation in this gene end up suffering from the disorder known as Duchenne muscular dystrophy. Girls who inherit the mutation only carry the disorder, but don’t suffer from it, since they inherit an extra, healthy X chromosome from their father.

• Scientists still don’t know what more than 50 percent of genes do. Also a lot of the DNA in our cells is "junk," that is, scientists don’t know exactly what the long stretches of repetitive DNA (usually long stretches of Gs and Cs) in our cells are for.

• On human chromosome 14, a gene called TEP1 codes for a protein that forms part of a chemical known as telomerase. Some cells turn immortal if you give them enough telomerase. That sounds good, but a cell line known as cancer also needs telomerase for its own immortality project.

• For centuries folklore had it that heredity passed through the blood. Think of the terms "bad blood," "mixed blood," "royal blood," "blue blood," or "bloodline." The irony is that there is no heredity coded in your red blood whatsoever. The red blood cells are the only kind of cells in your body that don’t have DNA?because they’re the only cells in your body that don’t have nuclei.

• Eight Mysteries Solved by DNA:

o Where is Columbus Buried?
o Was Albert DeSalvo the Boston Strangler?
o Did Sam Sheppard Kill His Wife?
o Did Thomas Jefferson Father Children with His Slave, Sally Hemings?
o Did Jesse James Die in 1882, or Did He Fake His Death?
o Could the Romanovs Have Survived the Russian Revolution?
o Was Anna Anderson Really Anastasia?
o Did the Last Dauphin Escape?
FACTS about DNA Testing

A paternity test is a way to determine the biological father of a child. It is a genetic test that compares many different genetic factors in the alleged father's sample with similar genetic factors in the samples of the child and mother.

Genetic tests have a 99 percent or greater accuracy rate in identifying the probable father. If the alleged father goes to court to say he isn't the father, but experts testify that his genetic tests show that 99 percent or more of his genetic factors match the child's genetic factors, the court will find that he is the father of the child until evidence to the contrary is presented to the court.

You do not need a doctor's order to have a Paternity Test.

Samples are taken from the donor in two basic ways- by drawing a blood sample or more commonly, by using a swab, (much like a Q-tip), to scrape off a few cells from inside the mouth.

The swab is a simple, painless way to collect cells from the cheeks inside the mouth. The DNA in the cells is then analyzed to see if the alleged father's DNA matches the child's DNA.

A person acquires all of his/her DNA at the time of conception. This DNA remains the same throughout lifetime. Therefore, the accuracy of the DNA parentage test is the same throughout lifetime. Highly accurate DNA test results may be obtained before birth

Testing can be performed if one of the parties resides in another city or state.

Results can be available in as little as 48 hours.

The samples do not have to be drawn at the same time.

. Affidavits, depositions and expert witness testimonies are always available with all paternity testing.

The Drug Testing USA - GENETICA DNA Test™ for paternity is the most extensive and accurate DNA test available, with typical power of exclusion of 99.999999%.

DNA Structure

DNA is composed of strands of nucleotides joined by phosphodiester bonds between the 5'-OH of one ribose and the 3'-OH of the next.
DNA forms a double helix with these strands, running in opposite orientations with respect to the 3' and 5' hydrozxy groups.
The double helix structure is stabilized by base pairing between the nucleotides, with adenine and thymine forming two hydrogen bonds, and cytosine and guanine forming three.
DNA is a flexible molecule, and can bend, twist, and kink.
Double helix DNA can be in three forms, A, B, and Z. The most common form is B-DNA, which has about 10 bases per turn of the helix.
The B-DNA form has two grooves, a major groove and a minor groove, with the major groove being wider and deeper.
Proteins and other molecules can interact with DNA, recognizing double-stranded DNA by the phosphoribose backbone, and forming specific interactions based on the DNA sequence through access to the major and minor grooves. Most interactions occur in the major groove due to easier acess because of its size, and because there is an additional potential hydrogen bond donor from A-T residues in the major groove.
Most circular DNA is supercoiled. This structure is more compact than the relaxed form.
Negatively supercoiled DNA is partially unwound, facilitating DNA replication, RNA synthesis, and interactions with other molecules, and is the preferred form of supercoiling for most organisms.
Enzymes which affect supercoiling are topoisomerases. Topoisomers are DNA molecules which differ only in their linking number. The linking number refers to the number of helical turns the molecule possesses.
Topoisomerases break one or both strands of the DNA, and allow the molecules to relax, removing supercoils before resealing the break. The enzyme maintains the energy of the phosphodiester bond by forming an intermediate linked through a tyrosine residue, and does not require an energy input.
Supercoils are added to DNA through the activity of DNA gyrase. This enzyme uses ATP to provide energy for the reaction, breaking both strands of DNA and passing a loop through the break to introduce negative supercoils.

DNA-...


This page:




Help/FAQ | Terms | Imprint
Home People Pictures Videos Sites Blogs Chat
Top
.