Cell theory is a universal theory proposed by three scientists namely: Theodor Schwann, Mathias Schleiden and Rudolf Virchow in the 1830's. The cell theory compose of three components:
- All living things are made up of one or more cells.
- Cells are the basic and fundamental unit of life
- All cells emanate from pre-existing cells.
Based on this question, these three components are what makes up the CELL THEORY.
Sexual reproduction happens when there is the involvement of two parents to give rise to the offsprings.
For the production of offsprings, each of the parents produces a haploid gamete and it is by the fusion of these two haploid gametes that a diploid organism is produced.
In the given situation, there are 19 chromosomes present in the haploid gametes this means that a diploid individual will have 2X19 = 38 chromosomes.
Now the underground stem cells are not gametes but somatic cells and the somatic cells are diploid and hence, they will have 38 chromosomes.