Question

in eukaryotes the length of the DNA is enormously large. expalin how much a long molecule fit into the chromosoes seen at metaphase?

Answer 1

• Length of DNA double helix in typical mammalian cell is about 2.2 metres and all of that DNA packaged so tightly into chromosomes and squeezed into a tiny nucleus.
• The haploid human genome contains approximately 3 billion base pairs of DNA. All are packaged into 23 chromosomes. Except for ova and sperm all cells are diploid, with 23 pairs of chromosomes. In total 6 billion base pairs of DNA in each cell. Each cell contains about 2.2 meters of DNA .It is estimated that the human body contains about 100 trillion meters of DNA.
• Certain proteins (Histones) compact chromosomal DNA into the microscopic space of the eukaryotic nucleus. Thus, within the nucleus, histones bind with DNA very tightly and provide the energy to fold DNA.