There are 10 chromosomes in the ovum of a plant. How many DNA molecules are in the root of this plant before dividing.

Sex cells contain a haploid or single set of chromosomes. And the cells of the body or somatic cells have a diploid, that is, a double set of chromosomes. The ovum is a germ cell, and the root cells are somatic cells, which means they have not 10, but 20 chromosomes. Each chromosome is made up of a DNA molecule.

But, just before the division, replication occurs in the cells, that is, the doubling of DNA molecules. This means that before the division, there will be 40 DNA molecules in the root cell of a given plant.