Meiosis: Who knows, me or DJ?

Net connection is awesome today.

I thought there was no DJ today, became surprised to see it was in the routine.

Today she discussed sex determination, chromosome, chromatin fibre, mitosis and meiosis. A question came in my mind when DJ was delivering her lecture. Why X and Y chromosome's are named so? I googled net and found the answer from Google books.

Q: Why X & Y chromosomes are named so?

Ans: A common misconception about X and Y chromosome is that they are named because of their shape. However, Hermann Henking named the X because it was mysterious, or exceptional in some way and that Nettie Stevens then simply continued the alphabetical sequence when she named the Y.

(Source: The X in Sex: How the X Chromosome Controls Our Lives By David. Bainbridge)

When DJ started mitosis and meiosis, I got confused whether she knows those terms or not?

Life starts through meiosis, after fusion of egg and sperm!!! I don't get any of this, especially when she is saying about Homo sapiens. (Her words are correct for haploid organisms who undergo meiosis when diploid zygote is formed.) I've to wait and see.

(Right click and open in new window or tab to view enlarged image)

Another confusion arose when she asked, "What is the difference between Chromatin fibre and Chromosome?" Different answers came from different corners. I think some of them were right, though weren't complete. Chromatin fibre is non-condensed string of nucleosome which divides and condenses before cell division. This condensed form of chromatin fibre is known as chromosome. (Appears H shape in typical karyotype). Anyway, DJ rejected them. Instead she accepted Maruf's lead (partially) which I found the least appropriate.

She also talked about Genetic Maps. I know there are three types of maps, but right now, I can't recollect.