00:01
Hey, what's up guys? so today we're going to talk a little bit about homologous chromosomes versus sister chromatids.
00:07
So these are some terms that you're going to see in the process of meiosis.
00:11
So i drew a little diagram to help us understand the difference between these terms.
00:15
So this chromosome arrangement is what you'll see at the beginning of meiosis 1.
00:21
Before synapsis or crossing over happens in prophase 1.
00:25
And after duplication of chromosomes, this is what you'll see.
00:28
So you have a pair of sister chromatoms.
00:30
From your mom, maternal, labeled in green, and from your dad, paternal, labeled in black.
00:38
So each of the single sister chromatids in the pair have identical genes, identical alleles to each other.
00:47
They were replicated in what's called the s phase of interphase before meiosis one began.
00:54
The same with the paternal pair.
00:55
So each sister chromatid in the sister chromatid pair that i labeled is identical.
01:03
But the pair of maternal sister chromatids and the pair of paternal sister chromatids together are called homologous chromosomes...