If an organism has a diploid , or 2n , number of 16 , how many chromosomes do its sperm cells or eggs cells contain?

A diploid cell contains two sets of chromosomes, one from the father and one from mother. In comparison, haploid cells contain only one set of chromosomes, either from father or mother. Thus, haploid cells contain half as many chromosomes as the diploid cells. In other words, if a diploid contains 2n number of chromosomes, a haploid will contain only n number of chromosomes. The sex cells, also known as gametes (sperm cells and egg cells), are haploids cells. Since, the given diploid contains 16 chromosomes, each of the sperm or daughter cells will only contain 8 chromosomes.

The gametes, containing only half the chromosomes (as compared to a diploid), interact with each other (sperm cell with a daughter cell) and thereby obtain the full set of chromosomes.

Hope this helps.