hey guyz ! unit 3 bio discussion , doubts in here !!

[étudiante]

LOL
and nah my sis not on it, sorry she is a very out-dated person SRSLY.

awwhh! wish dere were sum A2 ppl to discuss those practicals with
neways... no problemo

 

[DANGERBP]

okay... its basically this...
cut off the root tips, put them on a watch glass with ethanol on it n leave it for 12 hrs....
Next put them in cold water and dry wid filter paper
put in warm HCl
repeat till they are soft...
transfer to a slide. break with mounted needle..... add a drop of stain (either one)
Cover with cover slip, blot and squash
View under microscope.... chromosomes will be blue if u used toluidene blue or red if u used acetic orcein
crudely put.... dats it

hahah much better ! =p =p wats blotting though ?

 

[étudiante]

hahah much better ! =p =p wats blotting though ?

haha
blotting means pressing lightly with filter paper to remove any excess liquid

 

[Vj Destiny]

this one is using Toluidine Blue
1) Cut off 1-2 cm from several root tips of some growing garlic roots. Choose tips which are white and have a firm rounded end. Brown ones give poor results.
2) Put the root tips into a hollow glass block or a small sample tube containing 2cm3 1M hydrochloric acid for exactly 5 mins.
3) Transfer the root tips to a watch glass containing approx. 5cm3 cold water. Leave for 4-5 mins. then dry on filter paper. Handle the root tips gently as they will be fragile.
4) Transfer one of the root tips to a clean microscope slide. Cut about 4-5mm from the growing tip. Keep the rounded tip and discard the rest. The meristem tip is usually a denser white and more rounded than the cut end. If u take the wrong end, the presence of xylem will make maceration more difficult.
5) Gently break the root tip with a mounted needle (this is called maceration). Add one small drop of toludine blue and leave to stain for 2 mins.
6) Cover with a coverslip and blot firmly with several layers of tissue or filter paper. Press gently to spread the root tip, or tap gently the coverslip with the back of the pencil.
7) View under microscope (x 400 magnification) and look for cells containing chromosomes. If cells are overlapping, squash the slide between two wads of filter paper. Avoid lateral movement of coverslip.
8) Look for regularly shaped, actively dividing cells. DNA stains dark blue with toludine blue stain so you should be able to see blue groups of chromosomes against pale blue background.
9) If your preparation is not very successful, repeat with some of the other root tips from step 3). Try to adjust your procedure to remedy the problem; for example, if your cells are over- or understained, adjust the time they are left in the stain.

Godh ma teacher didnt say a word about dis all! :O Thankx a lol buddy

 

[U stalking ME]

Godh ma teacher didnt say a word about dis all! :O Thankx a lol buddy

Ur welcome

 

[DANGERBP]

haha
blotting means pressing lightly with filter paper to remove any excess liquid

thx hey i just noticed that the exp with orcein uses acetic acid first =p !

 

[étudiante]

thx hey i just noticed that the exp with orcein uses acetic acid first =p !

if ur using orcein directly den yes... u need to use acetic acid before
but u can directly go for acetic orcein

 

[DANGERBP]

if ur using orcein directly den yes... u need to use acetic acid before
but u can directly go for acetic orcein

why i feel like am barely gettin a thing ! =L

 

[étudiante]

why i feel like am barely gettin a thing ! =L

sorry! i'll be clearer...

Orcein itself if used as a stain needs to be reacted with Acetic acid to give acetic orcein...
But u can directly use Acetic Orcein if available n u wont need the reaction step

 

[DANGERBP]

sorry! i'll be clearer...

Orcein itself if used as a stain needs to be reacted with Acetic acid to give acetic orcein...
But u can directly use Acetic Orcein if available n u wont need the reaction step

oh no its not you !
its me i cant help gettin any info in my frkn mind !!

ya thx =p !
so same steps one with toloudine the other with acetic orcien !
thanks =p

 

[étudiante]

oh no its not you !
its me i cant help gettin any info in my frkn mind !!

ya thx =p !
so same steps one with toloudine the other with acetic orcien !
thanks =p

haha no its ok last minuite chills.. m already having dem n TEN days to go >.<

welx

 

[DANGERBP]

haha no its ok last minuite chills.. m already having dem n TEN days to go >.<

welx

good luck to u too ! =) =p

 

[étudiante]

good luck to u too ! =) =p

thanks u 2

 

[Arabella_18]

But these experiments have been there in previous years I doubt they will come again Jus saying

 

[DANGERBP]

But these experiments have been there in previous years I doubt they will come again Jus saying

no wat experiments ! dude mitosis never came ! so think it would be there ! ..

 

[étudiante]

But these experiments have been there in previous years I doubt they will come again Jus saying

dont rely on dat please... it DOESNT work dat way... u can even get the same experiment on the theory as well as the ATP paper... its a risk if u try 2 look for this type of pattern in ATPs especially... i suggest u do everything

 

[Arabella_18]

Yea Mitosis Dint come And even the totipotency thing did not show up

 

[Arabella_18]

Obv I aint relyin on that I hve Gone throu evrythin
Btw do you noe what to write if they ask to comment on the validity of the result ?

 

[DANGERBP]

ummm hey wat bout the totipotency experiment do we need to know anythin regardin strilizing using
(chlorate (I) solution Bleach)

 

[U stalking ME]

ummm hey wat bout the totipotency experiment do we need to know anythin regardin strilizing using
(chlorate (I) solution Bleach)

no i dont think u do :/