Arianna Mason

Diseases caused by genetic factors are controlled by alleles, which are versions of the same gene that code for different characteristics. Every person will receive one allele from each parent. These may be different or the same and each is typically either dominant or recessive. The influence of a dominant allele will overpower that of a recessive allele. One example of how alleles work to influence disease is the genetic basis of conditions that are known to be autosomal recessive. Sickle cell disease is an autosomal recessive condition. The gene that is responsible for sickle cell, HBB, has many possible…

The concept of complete dominance explains that a dominant version of a gene, otherwise known as a dominant allele, is always expressed over a recessive version or allele. If a person inherits at least one dominant allele, then they will have the dominant trait. However, a person must inherit two recessive alleles to have the recessive trait. Despite this clear-cut explanation, many physical traits are not a result of complete dominance. Codominance In some instances, neither allele is dominant over the other. This is called codominance and it results in the simultaneous expression of two physical traits (a physical trait…

Dominant and recessive are terms used to refer to the manner in which versions of genes influence physical characteristics. Individuals receive two versions, also known as alleles, of each gene from their parents. Generally, each can be either dominant or recessive (more complex categories do exist). For example, the gene BEY2, which is known by many other names, helps to determine whether an individual's eye color can be brown or blue (there are other genes that work with this one and result in other eye colors). The allele for brown eyes is dominant, while the allele for blue eyes is…

Scientists currently have no exact number for the amount of genes that humans have though the consensus is that it is anywhere between 20,000 and 25,000. With the question of how many genes there are in humans, several other issues come up. In order to count the number of genes we have, scientists must have a clear definition for the term "gene". They must also locate these genes and have the tools and resources available to arrive at an accurate number. These issues make seeking an answer surprisingly difficult and time-consuming. What is a Gene? A simple definition of a…

Cancer begins in our DNA, the material that stores our genetic information. This material is made of molecules called nucleotides that are partially made up of nitrogenous bases (one nucleotide has one base). The order of these bases that are attached to the rest of their respective nucleotides and represented by A's, T's, C's, and G's are what create the sequence of our DNA. When changed and not repaired by DNA repair mechanisms, these sequences that are vital to the function of our bodies' physiological processes can lead to a cancer diagnosis. Not All Changes Create Cancer  Fortunately, the vast…

DNA, or deoxyribonucleic acid, is the sequence within our cells that determines our individual characteristics. Most of the sequence (more than 99%) is identical between individuals; however, small sections are unique to each person.  The entire sequence of each person's DNA (what is called a genome) is made of individual molecules called nucleotides that come in four forms. These forms are determined by the portion of the nucleotide called a nitrogenous base. Each of the four nitrogenous bases, adenosine (A), thymine (T), guanine (G), and cytosine (C), has a complementary base (A and T are complementary and G and C…