The Story Of Biology

Answer me this what do you think a virus is to you? From what i discovered a virus is you may have something to add to what i have found. From what i have discovered a virus is a infectious agents, not living organisims. It is true that they can reproduce and sustain a population, however this is only possibble with a host cell. A virus is composed of a protein capsid and internal nucleic acid(DNA or RNA). This is where the infectious agent comes from. There is and arugument over wether a virus is a living thing is the fact that all organisms including humans require external nutrients like calories, oxygen, and water.



What Is A Gene?

A gene has been defined in the early 20th century as the unit of heredity. The physical nature of a gene was not known then, but conceptually explained the 'laws' of inheritance of traits as first described by Gregor Mendel. This 'unit of heredity' is a powerful and suggestive idea and without doubt has been shaped by the concurrent discovery of the atom by physicists - that nature is organized into smallest units that form building blocks of matter. Organized in the right way, these building blocks are the foundation of every substance and life form known to man. So what do we know about genes today? They are best identified as units of DNA responsible for the synthesis of proteins and RNA components of cells (see also 'Molecular Biology of the Gene'). In molecular biology, the gene has a clearly defined meaning of a DNA sequence at a physical location (locus) on a chromosome.


Red Blood Cells

A major function of the red blood cells is to carry oxygen to all the tissues from the lungs. The red blood cells than transport the carbon dioxide from the cells because of breaking down the nutrients
The reason the erythrocytes are known as red blood cells is because of a substance called hemoglobin. Hemoglobin is composed of simple protein and iron pigments and when combined with oxygen their color becomes a bright scarlet.
Red blood cells are made in the red bone marrow. In infants every bone in their body produces red blood cells. In the adult the red blood cells can be produced in the thoracic bones, vertebrae, cranial bone and ends of femur and humerus bones. Red blood cells only live for approximately 120 days. The blood contains about 25 trillion red blood cells and has to replace them at about 3 million per second. If for some reason there is a red blood cell deficiency a problem called anemia can arise.


Autosomal Recessive Inheritance
Genes are the blueprints for making the substances, called proteins, our bodies need to develop and work properly. Most genes come in pairs, one of which is inherited from the mother and the other from the father. A mutation is a change in a gene that prevents it from working properly. Mutations in genes are inherited from our biological parents in specific ways. One of the basic patterns of inheritance of our genes is called autosomal recessive inheritance.
What is autosomal recessive inheritance?
Click Image to Enlarge
Autosomal recessive inheritance means that the gene carrying the mutation is located on one of the autosomes (chromosome pairs 1 through 22). This means that males and females are equally affected. "Recessive" means that both copies of the gene must have a mutation in order for a person to have the trait. One copy of the mutation is inherited from the mother, and one from the father. A person who has only one recessive gene mutation is said to be a "carrier" for the trait or disease, but he/she does not have any health problems from carrying this one mutation. Most people do not know they carry a recessive gene mutation for a disease until they have a child with the disease. Once parents have had a child with a recessive disease, there is a one out of four, or 25 percent chance, with each subsequent pregnancy, for another child to be born with the same disorder. This means that there is a three out of four, or 75 percent chance, for another child to not have the disease:
The birth of a child with a recessive condition is often a total surprise to a family, since in most cases, there is no previous family history of the condition. Many autosomal recessive conditions occur this way. It is estimated that all people carry about 20 recessive genes that cause genetic diseases or conditions. It is only when a person has a child with a partner that carries the same recessive gene mutation, that there is a chance of having a child with a recessive disorder. Mutations in certain genes have occurred over time in different parts of the world. Virtually anyone can carry a mutation in any one of the recessive genes; however, there may be certain ethnic groups more likely to carry certain recessive gene mutations, because of where the mutation originated.