why is the initial number of chromosomes in a eukaryotic cell refreed to as diploid (2n)?

Question

what does the n represent?

Answer 1

It varies with the type of eukaryotic cell, meaning that different eukaryotic organisms have a different number of chromosomes. n refers to the number of homologous chromosomes in the entire set of chromosomes. In diploid species, there are two sets of more or less identical chromosomes that contain the same genes on them. (They're not quite identical because the two chromosomes have different alleles of many of those genes.) Each pair of "identical" chromosomes is said to be homologous, and the n refers to the number of homologous pairs in the species. For example, in humans n=23, with 22 autosomes plus two 2 sex chromosomes. In Drosophila (fruit flies) I think n=4. Regardless, different species have a different number of homologous chromosomes.

Answer 2

Because the chromosomes (usually) come in
pairs each one of the pair bearing genes for the
same set of traits, and similar in size and shape.
When gametes (ova and sperm) are produced the
number of chromosomes is cut in half, just one of
each pair entering the gamete. At fertilization the
normal number of chromosomes of the species is
restored. The chromosome number of the gamete
is referred to as haploid, from the term for half,
the number in the fertilized egg being diploid, for
double, because it is twice the number in the gamete.

Not all eukaryotic cells are diploid. In some animals, bees for instance, the males develop from
unfertilized eggs and are therefore haploid. This
is true of some other organisms as well. There are
also cases, fairly common in plants, of duplication
of the chromosome set so that you may get
triploid, tetraploid, etc. cells.

Answer 3

'cuz each gamete contributes 'n' number of chromosomes, which results in 2n chromosomes in the final cell. Humans (male and female) each contribute n=23 chromosomes to their embryos, which finally contain 46 (or 2n) chromosomes...