Overview of DNA, genome, gene, RNA, chromosome

DNA is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms with the exception of some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints, like a recipe or a code, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules. The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information.

DNA consists of two long polymers of simple units called nucleotides, with backbones made of sugars and phosphate groups joined by ester bonds. These two strands run in opposite directions to each other and are therefore anti-parallel. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a process called transcription.

Within cells, DNA is organized into long structures called chromosomes. These chromosomes are duplicated before cells divide, in a process called DNA replication. Eukaryotic organisms (animals, plants, fungi, and protists) store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast, prokaryotes (bacteria and archaea) store their DNA only in the cytoplasm. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.

Humans have 46 chromosomes. There are a total of 23 pairs of chromosomes or 46 total chromosomes.Chromosomes are made up of long strands of DNA which contain all the body’s genes.following screen cast describes more details.

In this post I tried to understand that a genome is made up of a collection of DNA chromosomes. Those contain stretches of DNA that are called coding and non-coding. Gene is the functional unit of heredity which is passed down from our parents. The sequences of genes formed the DNA. DNA is the code information to produce the protein in our body. We called it chromosome when we grouped all DNA in a structure. And a complete set of chromosomes which inherited as a unit from our parents is called genome .

Learn about D.N.A (^^)

(sources wiki and houstuffworks,bimatics)