Somatic cell (before S phase): 46 chromosomes, 46 chromatids, 23 pairs of homologous chromosomes, 0 pairs of sister chromatidsįor a male, this would look like: A a, B b, C c, D d, E e, F f, G g, H h, I i, J j, K k, L l, M m, N n, O o, P p, Q q, R r, S s, T t, U u, V v, W w, X Y Or, you could say you have 46 pairs of sister chromatids, but still 23 pairs of homologous chromosomes.
In this way, you do have 92 chromatids, but still only 46 chromosomes. However, the 2 'A' chromatids are still linked together by the hip, and thus are considered to still be only one chromosome. When DNA is replicated, you now have 2 copies of the 'A' chromosome (or 2 'A' chromatids) and 2 copies of the 'a' chromosome (2 'a' chromatids), 2 'B' and 2 'b', and so on. 'A' and 'a' are still 2 different chromosomes, though they are homologous to each other (code for the same genes). you have an 'A' chromosome (1 'A' chromatid) and an 'a' chromosome (1 'a' chromatid), 'B' and 'b', 'C' and 'c' and so on, each coming from a different parent. In a regular somatic cell (before DNA is replicated in the S phase), there are 46 chromosomes - 23 of each kind as well as their homologous opposite. I think another way to think about it is remembering the difference between 'sister chromatids' and 'homologous chromosomes'.