The diploid amount of chromosomes is also represented by the symbol 2n. In a sexually reproducing organism, one haploid set of chromosomes(n) is contributed to the offspring by the male sex cell or sperm and the other haploid(n) set is contributed by the female sex cell or egg. When fertilization restores the diploid or 2n amount of chromosomes, they are arranged in homologous pairs. In the problem above, you are stating that the 2n amount of chromosomes is 16. Therefore, there will be 8 homologous(similar) pairs of chromosomes--these are contributed by both the mother and the father at fertilization. These homologous chromosomes have a similar length, staining pattern and centromere placement and corresponding genes on both chromosomes in a pair.