It is present in the chromosomes.

  • DNA is an acronym for deoxyribonucleic acid. It is present in the chromosomes.
  • Chromosomes are present in the nucleus of every cell. From parental generation, DNA is passed on to the offspring through the gametes
  • DNA is a double helical structure having nucleotides
  • These nucleotides are made up of deoxyribose sugar, phosphoric acid, and nitrogenous bases such as adenine, thymine,cytosine-guanine
  • The nucleotide sequence of the DNA molecule is called gene
  • The genes are thus present on DNA
  • A type of gene is responsible for synthesis for a particular protein
  • The changes in a gene can alter the characteristics of organisms
  • James D Watsonand Fransis Crick proposed the double helix or spiral staircase structure of the DNA molecule in 1953They were awarded a Noble prize for this discovery
  • DNA is the largest biomolecule/macromolecule of the cell.
  • It is a double-stranded molecule, with two strands running anti-parallel to each other, often called the DNA duplex forming the twisted ladder like characteristic helix structure.
  • There are a total of five types of DNA: B-DNA, Z-DNA, A-DNA, C-DNA, and D-DNA. The most common type is the B-DNA.
  • Due to its spiral twisting, the DNA duplex has two alternative grooves, major groove located 22 Å away from the starting nucleotide and the minor groove 12 Å away.
  • The two strands of a DNA molecule are connected by a single Hydrogen bond, or H-bonds as they are commonly referred to. At temperatures of above 90 degree Celsius, the strands disintegrate and break down. This process is known as denaturation.
  • The two strands of DNA: sense and anti-sense strands are not both involved in controlling the metabolism and heredity. Only the coding strand/anti-sense strand acts as a template for RNA synthesis.
  • All of the DNA are not the genes, in fact, the genes make up only about 3% of the total DNA.
  • About 99% of the human DNA is similar to every other human, it is the other 1% that gives each of us a unique identity.
  • The DNA nucleotides may be classified as Purines or Pyrimidines, based on their molecular structure. Adenine & Thymine are Purine structures with their double-ringed molecular structure. Guanine & Cytosine are Pyrimidine structures with their single-ringed molecular structures.
  • DNA is a very fragile molecule and can get easily damaged. Furthermore, frequent errors in genetic transcription, cell damage from overexposure to UV light, are some of the few examples of reasons why this creates a change in the gene sequence. While some of the genetic damages are undone or repaired, others are inherited over multiple generations and are referred to as mutations.
  • It may be noted that the haploid set or half the number of total chromosomes present in the individual of an organism is termed as the genome. Each human cell has 23 pairs or 46 chromosomes. The human genome has 23 chromosomes. The egg and the sperm cells are the only haploid cells in the human body.
  • If you could type 60 words per minute, for eight hours a day, it would take approximately 50 years to type the complete sequence of the human genome.
  • The International Space Station possesses a copy of the genome of famous individuals like Stephen Hawking and Lance Armstrong, so as to be able to resurrect humanity in the event of apocalyptic destruction of the planet.
  • When an organism shows the presence of two sets of DNA, it is called a chimera. It usually occurs due to the fusion of multiple fertilized eggs during embryogenesis or as a result of an organ or bone marrow transplant. A famous example is Venus, the Two-Faced Cat who was born with different sets of genes on each side of its body.
  • The genetic material can be modified to produce genetically modified plants and microbes, this is where the science of Genetic Engineering steps onboard.
  • A team of scientists successfully encoded the lyrics of the song “It’s a Small World After All” into the genome of a bacterium, with the intent of developing a method to pass on messages for future intelligent life forms.
  • There are four types of DNA nucleotides: Adenine, Thymine, Cytosine, Guanine. The nucleotides are nitrogenous bases, made either from ribose sugar that makes RNAs or deoxyribose sugar that makes DNAs.
  • Deciphering the sequence of human genome surely isn’t simple or easy. However, in 2003, scientists accomplished their goal of deciphering the entire sequence of the human genome, as a part of the Human Genome Project!
  • In 1958, scientists Matthew Meselson and Franklin Stahl proved that the DNA replication was semiconservative. Both DNA strands replicate independently of each other, that way an original strand is incorporated with newly replicated DNA strand which makes it a semi-conservative method of DNA replication.
  • Did you also know that not all the genes incorporated in the DNA are alike, or even functional? A detailed molecular anatomy study has revealed a gene to have Cistron, Muton, and Recon. A cistron is what we call a gene functionally. Muton, the smallest unit change in a pair of nucleotides, is a unit measurement of mutation. The Recon comes into action when the gene undergoes recombination and crossing-over during cell multiplication.
  • Z-DNA is the only left-handed DNA type, which simply refers to the direction of coiling of the DNA strand.
  • The double helical strands are 20-26 Å apart depending upon the type of the DNA, and each nucleotide unit or, what is also the base pair is 3.3 Å wide.
  • Funnily enough, human DNA is also 98% identical to chimpanzees, and 50% to a garden cabbage.
  • Approximate 8% of the human genome contains junk DNA, residual sequences of the viral genome, from the viruses that infected our ancestors.
  • DNA is made up of nucleotides, which are supported by a backbone of polynucleotide chains, and alternating sugar-phosphate groups.

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