What Are Units or Particles of Hereditary Characteristics?

What is a Gene?

• A gene is made up of the DNA that defines the individual containing that gene and is located in the nucleus of a cell. Genes are the most basic unit of heredity and contain the instructions for constructing vital proteins. Genes come in many different sizes; some very small and some relatively very large. Organisms of the same species have more than 99 percent of the same genes from one individual to the next with only slight variations to a few genes. These special genes are called alleles and account for the slight differences between individuals.

Transcription

• The primary function of a gene is to make proteins. To create a protein, a gene goes through two processes: transcription and translation. In transcription, all the instructions held within the gene, in DNA, is transferred to a DNA-like molecule called messenger RNA in the nucleus. The RNA transfers the information from the DNA and out of the cell's nucleus into a liquid called cytoplasm, which contains all of the major components of the cell besides the nucleus.

Translation

• Translation is the second step in transforming a gene into a protein. Once the code from the DNA is transferred to the cytoplasm, the RNA interacts with a ribosome that translates the code for another type of RNA called transfer RNA. This RNA constructs the protein based on the instructions received from the ribosome and continues until the ribosome reaches a sequence in the code telling it to stop. The process of constructing these proteins is essential to life because proteins carry out most duties inside a cell.

Heredity

• Heredity is the process of passing the genetic traits of an organism to its offspring. Heredity is the driving force of evolution as mutations in genes are inherited from one generation to the next and can be either harmful, beneficial or neutral to the organism. Mutations granting even a slight advantage to an organism's ability to survive are important when passed down to offspring through genetic inheritance. An offspring inherits exactly half of its genes from its mother and half of its genes from its father.