Timeline for Why is using the definite article “the” before a plural countable noun correct in this case when I have not mentioned the plural noun before?

11 events

when toggle format	what		by	license	comment
Apr 30, 2021 at 4:22	history	edited	Ted Brown		edited tags
Apr 30, 2021 at 4:12	history	edited	Ted Brown	CC BY-SA 4.0	deleted 14 characters in body
Apr 30, 2021 at 4:02	history	edited	Ted Brown	CC BY-SA 4.0	deleted 5 characters in body
Apr 27, 2021 at 17:41	vote	accept	Ted Brown
Apr 27, 2021 at 17:06	history	edited	Ted Brown	CC BY-SA 4.0	deleted 12 characters in body
Apr 27, 2021 at 13:05	answer	added	Canadian Yankee		timeline score: 5
Apr 27, 2021 at 6:45	comment	added	Benjamin Harman		The double membrane is not encasing unspecified chromosomes or chromosomes in general. The double membrane is encasing specifically the chromosomes found in the aforementioned nucleus. That's why "the" is required.
Apr 27, 2021 at 5:52	history	edited	Ted Brown		edited tags
Apr 27, 2021 at 5:51	comment	added	user405662		Articles ain't prepositions. The two are chalk and cheese apart. Anyway, it's apparently the human set (23 pairs) of chromosomes that's being referred to here thus making it a specific set— which is why the definite article is there.
Apr 27, 2021 at 5:51	review	First posts
Apr 27, 2021 at 5:55
Apr 27, 2021 at 5:45	history	asked	Ted Brown	CC BY-SA 4.0