A gamete such as an egg cell receives one chromosome from each pair. How many chromosomes does one human egg cell contain?

Explanation

Taking one chromosome from each of the 23 pairs gives a gamete a single set of that size. Keeping the whole body-cell number would double the count at fertilisation, since the two gametes add their chromosomes together to make the new cell, and a count of two would describe one pair rather than a full set.