The cases with antecedent ...

Question

Can I use que instead of el/la/los/las que? Would the meaning be similar only with less emphasized pronoun ... who instead if the one who?Aquella mujer, que/ la que...

Answer

Hola Emanuel,
Yes you can. But as you correctly guessed, omitting el, la, los, las, will then express a less specific clause. For example, this sentence from the lesson:

Aquella mujer, la que tiene el pelo negro, es la madre de Antonio.
That lady, the one who has black hair, is Antonio's mum.

vs
Aquella mujer, que tiene el pelo negro, es la madre de Antonio.That lady, who has black hair, is Antonio's mum.
The second sentence without "la" is giving an extra description about the lady. That's it. I don't actually think the comma is necessary... "The lady who has black hair is Antonio's mum."
The first one using "la que" is being more precise; it is singling her out from a group of ladies, or a group of people: "the one who has long hair [not the others with different hair]"
Saludos
Inma

Answer

¿“Aquella mujer, la que tiene el pelo negro, . . .” igual a “Aquella mujer, la de pelo negro”?