Biology help needed....once again :)

[XPFMember]

Assalamoalaikum!!
May I plz know what's the difference between chromosomes and chromatin?
cuz during the interphase...one place it's written chromosomes aren't visible and one place it's written chromatin isn't visible !!
Plz help!
Jazak Allah Khairen!!

 

[larina]

Walaikumusalam.
chromosomes are 2 chromatids joined together by a centromere. each chromatin is made up of one DNA(a double helix molecule) and consists of genes.
while chromatins are the loops of chromosomes in the the nucleus(in nucleuplasm)
well, about the answer of other part, we'll do it tomorrow in the school InshaAllah so i can be able to tell u by then

today, in the school our teacher taught us about the synthesis part of the interphase part of the cell cycle, she told us that the chromosomes are originally 1DNA= 1 chromatin...later, in the interphase part of the cell cycle, it divides and forms a double structure. so is that true that the chromosomes are single chromatid initially???

 

[hassam]

ya its tru i saw a mcq related to this thing

 

[hassam]

@math angel...chromatin do not show up under microscope normally but during prophase The chromatin fibers become more tightly coiled, condensing into discrete chromosomes observable with a light microscope.....chromatids is different thing...see the pic

 

[hassam]

http://www.youtube.com/watch?v=s9HPNwXd9fk
perfect video watch this

 

[XPFMember]

so that means they r 2 diff things....r they both not visible during interphase??

 

[hassam]

pair of sister chromatids or a single chromatid ---both r one chromosomes

 

[XPFMember]

actually i'm talking about chromatin!!i think it's different than chromatid..isnt it??

 

[larina]

yes it is..chromatin is the found inside the nucleus formed of loops of ''chromosomes''. while chromatid is the ''part'' of the chromosome(2 chromatids form 1 chromosome)

 

[XPFMember]

so i think hassam told about chromatid not chromatin...isnt it ??
so now read my question again and help me out plz...

 

[larina]

well before the interphase, the chromosmes are not visible
during interphase stage of the cell cycle, the chromosomes thickens and shortens and becomes visible.
the chromosomes(1 chromatin) then forms 2 chromatin (chromosome-double structure)
the nucleus then divides by mitoses(4 phases)
the cell division takes place.
about the invisibility of the chromatid, i dont know, i think we should make reseach on that one. btw where did u read this statement?

 

[XPFMember]

Actually teacher said that CHROMOSOMES becomes invisible!
And on biologymad.com it's said that CHROMATIN becomes invisible!


i'm a lot confused.... :?

 

[larina]

i think they meant the same. because chromatins are the loops of chromosome
so as the chromosomes become invisible, the whole chromatin becomes invisible.