Genetics is the branch of biology dealing with the legacy and its variation.
The legacy is that the offspring tend to resemble their parents, based on the fact that our appearance and function, ie our phenotype, is largely determined by our genetic makeup, that is our genotype.
However, we must bear in mind that the expression of many genes, and therefore the expression of the corresponding phenotypes, is influenced by environmental factors.
This discipline involves the study of cells, individuals, their descendants, and people who live in the agencies. Investigate the genetic variation of all forms of hereditary and the underlying molecular basis of such characteristics. Thus Genetics has been divided into three main branches: classical genetics (also known as Mendelian genetics or transmission), molecular genetics and population genetics.
What is the heart of heredity in the cell?
Eukaryotic organisms are characterized by the presence of a nucleus in which the genetic material. In prokaryotes, such as bacteria, the genetic material is in an area not limited, but recognizable, the cell called nucleoide. In viruses, the genetic material is sheathed in a head cover or a protein called viral capsule.
What is the genetic material?
Both in eukaryotes as in prokaryotes DNA (deoxyribonucleic acid) is the molecule that stores genetic information. RNA (ribonucleic acid) is the genetic material of some viruses. These are the two types of nucleic acids that are found in organisms. Nucleic acids, along with carbohydrates, lipids and proteins, are the four main classes of organic molecules that characterizes life on our planet.
What is a gene?
In simple terms, the gene is the functional unit of heredity. In chemical terms is a linear chain of nucleotides (chemical blocks that make up DNA and RNA). A conceptual definition is regarded as a data storage unit capable of suffering replication, mutation and expression.
What is a chromosome?
The genetic material is packaged in discrete units called chromosomes. While some viruses have several chromosomes, most have only one, consisting of a single molecule of DNA or RNA. Depending on the type of virus, the molecule can be unicatenaria or bicatenaria, linear or circular. The bacterial chromosome is a molecule composed of a circular DNA bicatenaria associated proteins and RNA. Some bacteria have additional genetic elements called plasmids, small size and circular DNA bicatenario.
In eukaryotic cells, each chromosome is a DNA molecule bicatenario associated with basic proteins called histones and other proteins histónicas. The role of histones is to provide the structural support of DNA in a complex fiber structure, the chromatin, which is the basic subunit nucleosoma.