Why is it necessary for DNA to duplicate before cells divide?

Answer 1

All diploid organisms have two sets of chromosomes, one maternal and another paternal. This is the case in somatic or body cells and in gamets or sex cells, there is only one set of chromosomes. During somatic cell division, the cell needs to keep the size of its genome. If the two sets are split into two daughter cells, there would be only one set in each daughter cell and that leads to reduction, which is called Meiosis and only occurs in the case of gamets. To prevent this reduction and maintain genome stability, a simple mathematical biology is applied where right before cell division the DNA copies are duplicated so that each daughter cell gets two sets as had the parental cell. This is the main reason for duplication. But other significant processes such as homologous recombination which leads to genetic variation also take place during cell division.

Answer 2

so that both news cells can take a copy of the DNA for themselves as they divide. In fact it is the duplication of the DNA that causes the division of the cell. A cell is mainly a "home" for the DNA.

Answer 3

DNA looks like a set of helical ladders. When a cell divides all the "ladders" (chromosomes) split into two one-rung ladders right down through the rungs. Each of the two new cells gets one half of each ladder and a "soup" of spare parts (molecules) rebuild the missing half of each ladder giving both cells a complete set of whole DNA chromosomes. Therefore each cell gets an entire blueprint of the human body and the cell can differentiate to produce the needed type tissue (bone, skin, gland, etc.) needed at its location.

Answer 4

Because two cells need two lots of DNA

Answer 5

Because otherwise both cells would not have DNA