Answer:
38
Explanation:
Haploid cells contain a single set of chromosomes (i.e. only one chromosome "1", one chromosome "2", one chromosome "3", etc.).
Diploid cells contain two sets of chromosomes (i.e. two chromosomes "1", two chromosomes "2", two chromosomes "3", etc.), and each set was inherited from a different parent.
In diploid individuals, the only haploid cells are the gametes, that are produced by reducing by half the chromosome number of diploid cells in a process called gametogenesis. When a male gamete and a female gamete combine, a diploid zygote is formed, which will divide mitotically during development until an adult diploid individual is grown.
Because the haploid number is half that of diploid cells, we have to double it to obtain the diploid number. The haploid number in sphagnum moss is 19, so the diploid number is 38.
