dna structure

dna structure

In all that we see in nature, the principle that we usually see is that form follows function. This is because in almost all creatures and plants, the unique features that they have serve a purpose. One example of this includes how some creatures are able to camouflage themselves within their background because their skin color allows them to do so. Other examples include birds with specially shaped beaks to help them catch prey, and the woodpecker is a good example of this. However, this principle does not only apply to the physical attributes of animals and plants as this principle is also followed up to the molecular level. This is seen on how the structure of the most basic genetic molecule, which is DNA also follows this principle.

Form follows function

The function of DNA is for replication and the transfer of genetic information. Given this, it can be expected that the structure of DNA would be designed to serve these functions. For its replication function, the two-strand structure of DNA molecule allows for the separation of these two strands to be able to bind with newly developing DNA molecule. This means that the two strands can "give birth" to a limitless number of DNA molecules as long as the replication process goes on.

For its genetic information transfer function, the way by which DNA molecule is made up of sub-units that contain a sugar, a phosphate group and four nitrogenous bases allows for the molecule to be arranged in a way by which a code is formed. This code is determined by the sequence of the four nitrogenous bases namely, adenosine (A), cytosine (C), thymine (T), and guanine (G). During the replication process, this code is transferred to the new DNA molecules that are formed through a process by which a gene that is formed or coded in the same sequence in which the nitrogenous bases are sequenced in the DNA. These genes then determine the proteins that make up and establish the biological characteristics of an organism.

As with anything in nature, DNA also follows the principle that form follows function. This is because the unique structure of DNA allows it to serve its two main functions, which are the replication and the transfer of genetic information.

By:Kristy Annely

Article Source: dna structure

dna profiling

dna profiling

DNA Profiling and Its Uses in Court

Stronger evidence in courtrooms--it's what every attorney, defendant, and plaintiff dreams of. Beginning in the last 1980s, this is exactly what began to surface through DNA profiling.

In addition to the one-of-a-kind pattern engraved on our fingers, each of us possesses a unique identifier that is built within our bodies. DNA (deoxyribonucleic acid) is the genetic blueprint that determines our biological characteristics. DNA is a long molecule located in almost every cell in the human body. When we are conceived, we inherit half of our DNA from our mother and half from our father. Although every human's DNA is 99.9% identical, the remaining 0.1% is enough to uniquely identify an individual. Our DNA is made up of about 3 billion base pairs, the building blocks of DNA composed mainly of carbon and sugar. The 0.1% (3 million) base pairs that make us unique are what constitute our DNA fingerprint.

Over the past 20 years, courts have been able to rely upon the consistent accuracy of DNA profiling, also known as DNA fingerprinting, to solve crimes. DNA profiling has even been used to solve crimes that are more than 30 years old.

Here's how DNA profiling is done:
# Specimens are collected from the crime scene. Anything can be used to extract DNA: Hair, blood, bodily fluids, etc. In some cases, victims may have scratched their attackers, in which case skin cells can be extracted from underneath the victim's fingernails in order to identify the criminal
# The DNA needs to be isolated and cut so that it can be matched against other samples. Special enzymes recognize patterns in the DNA and cut the strand
# In a process called electrophoresis, the strands are then placed on a gel where they are separated an electric current passed through it.
# The resulting fragments are compared against samples of all suspects and a match is determined.

DNA profiling is mostly used in sexual offences (60%), homicide (20%), assaults (7%), robbery (7%), criminal damage (1%), and other cases (5%).

DNA profiling narrows the list of suspects that authorities need to work through. The FBI commented that DNA profiling allows them to dismiss one-third of rape suspects because the DNA samples do not match. Authorities recognize the possibility of specimens being planted at crime scenes, and therefore continue to investigate the crime based on motive, weapon, testimony, and other clues in order to more accurately solve the case.

Article Source: dna profiling

structure of dna

structure of dna

In all that we see in nature, the principle that we usually see is that form follows function. This is because in almost all creatures and plants, the unique features that they have serve a purpose. One example of this includes how some creatures are able to camouflage themselves within their background because their skin color allows them to do so. Other examples include birds with specially shaped beaks to help them catch prey, and the woodpecker is a good example of this. However, this principle does not only apply to the physical attributes of animals and plants as this principle is also followed up to the molecular level. This is seen on how the structure of the most basic genetic molecule, which is DNA also follows this principle.

Form follows function

The function of DNA is for replication and the transfer of genetic information. Given this, it can be expected that the structure of DNA would be designed to serve these functions. For its replication function, the two-strand structure of DNA molecule allows for the separation of these two strands to be able to bind with newly developing DNA molecule. This means that the two strands can "give birth" to a limitless number of DNA molecules as long as the replication process goes on.

For its genetic information transfer function, the way by which DNA molecule is made up of sub-units that contain a sugar, a phosphate group and four nitrogenous bases allows for the molecule to be arranged in a way by which a code is formed. This code is determined by the sequence of the four nitrogenous bases namely, adenosine (A), cytosine (C), thymine (T), and guanine (G). During the replication process, this code is transferred to the new DNA molecules that are formed through a process by which a gene that is formed or coded in the same sequence in which the nitrogenous bases are sequenced in the DNA. These genes then determine the proteins that make up and establish the biological characteristics of an organism.

As with anything in nature, DNA also follows the principle that form follows function. This is because the unique structure of DNA allows it to serve its two main functions, which are the replication and the transfer of genetic information.

Article Source: structure of dna