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

[étudiante]

LOL same here, i also took the same subjects except S1, coz thats offered in A2
But srsly M1 is soo shity. I wasnt present for half the thing soo i think i am gonna fail it. I just wish vectors doesnt come. :S
Anyways goodluck for tom.

DAMN THE VECTORS PART

n good luck 4 2omorrow guys

 

[étudiante]

heh ya then its nothin you just need to focus on the way nd the same steps r repeated to every question =p !
dude antimicrobial came in 2010 jan nd in may the enzyme was there =p ! but ya could be anythin =p
planin meaning wat ?
haha ya vitamine c is easy too so sure it wont b there =p=p lol
ya me too =) =p

we feel recent experiments wont come but dont be too sure they can put them in to catch u out happened wid us kinda... >.<
Planning is what you do before the experiment starts... as in deciding wat varaiables to control, risk-assessment, apparatus n stuff like dat....

ok
Planning = Procedure

sorry... but thats not true... planning is what u do in order to decide about the procedure

 

[étudiante]

umm guyz are the variable to b controlled same as factors to b controlled ? =$

yes

 

[U stalking ME]

DAMN THE VECTORS PART

n good luck 4 2omorrow guys

thank u

 

[étudiante]

thank u

ur welcum

 

[U stalking ME]

heh dude procedure for doin the experiment ?? that never comes right ??

it never does but it can i guess plus planning does not mean procedure see étudiante's reply, sorry for the mistake :/

 

[étudiante]

it never does but it can i guess plus planning does not mean procedure see étudiante's reply, sorry for the mistake :/

the procedure doesn't usually come for AS... but u need to know the reason behind and the precautions for each step in the procedure

 

[U stalking ME]

the procedure doesn't usually come for AS... but u need to know the reason behind and the precautions for each step in the procedure

Oh okay thanks again!!

 

[étudiante]

Oh okay thanks again!!

Your welcome

 

[DANGERBP]

we feel recent experiments wont come but dont be too sure they can put them in to catch u out happened wid us kinda... >.<
Planning is what you do before the experiment starts... as in deciding wat varaiables to control, risk-assessment, apparatus n stuff like dat....


sorry... but thats not true... planning is what u do in order to decide about the procedure

oh so the new ones you mean ? totipotency nd mitosis ? shit ! =p okay .. i was planin on studyin them nd thts it ! nd if theres time ide go for readin the rest ! shit man think gotta study everythin !! !

oh nd thnk you ! =p =)

 

[DANGERBP]

umm i gotta question ! again =/
Describe how you would prepare a root tip squash ?? hows that exactly i need all the steps !
thankss !

 

[étudiante]

oh so the new ones you mean ? totipotency nd mitosis ? shit ! =p okay .. i was planin on studyin them nd thts it ! nd if theres time ide go for readin the rest ! shit man think gotta study everythin !! !

oh nd thnk you ! =p =)

dont miss nething
ur welcum

 

[DANGERBP]

it never does but it can i guess plus planning does not mean procedure see étudiante's reply, sorry for the mistake :/

=) don worry =p !

 

[U stalking ME]

umm i gotta question ! again =/
Describe how you would prepare a root tip squash ?? hows that exactly i need all the steps !
thankss !

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.

 

[DANGERBP]

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.

dude you fkn kiddin me !! all that ! 0.O
plus wats the difference bet this one nd the other one using oracien ? !

heh thanks =p

 

[U stalking ME]

dude you fkn kiddin me !! all that ! 0.O
plus wats the difference bet this one nd the other one using oracien ? !

heh thanks =p

LOL yea all this
For orcein ethanoic stain:
1) put a test tube containing 2cm3 1M hydrochloric acid into a water bath at 60 degrees celcius
2) 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.
3) Put the root tips in a watch glass containing approx. 2cm3 of acetic alcohol for a minimum of 12 hrs.
4) Remove the root tips and place them watch glass containing approx. 5cm3 cold water. Leave for 4-5 mins. then dry on filter paper. It is important to blot the tips well to remove the water at this stage or a precipitate may form wen staining.
5) Put the root tips into a preheated hydrochloric acid for exactly 5 mins.
6) Repeat step 3). Handle the root tips gently as they will be fragile.
and then steps from 4) to 9) from the Toluidine Blue one. not step 8) it will be different u will say DNA stains red/black with acetic orcein so u should be able to see red/purple chromosomes against a pale pink background.

 

[étudiante]

dude you fkn kiddin me !! all that ! 0.O
plus wats the difference bet this one nd the other one using oracien ? !

heh thanks =p

i dont think u really need 2 know this part... at least i haven't studied it... r u sure this is required?
if ur talking abt acetic orcein.... then there isnt any much difference, just the stain used is different...

 

[étudiante]

LOL yea all this
For orcein ethanoic stain:
1) put a test tube containing 2cm3 1M hydrochloric acid into a water bath at 60 degrees celcius
2) 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.
3) Put the root tips in a watch glass containing approx. 2cm3 of acetic alcohol for a minimum of 12 hrs.
4) Remove the root tips and place them watch glass containing approx. 5cm3 cold water. Leave for 4-5 mins. then dry on filter paper. It is important to blot the tips well to remove the water at this stage or a precipitate may form wen staining.
5) Put the root tips into a preheated hydrochloric acid for exactly 5 mins.
6) Repeat step 3). Handle the root tips gently as they will be fragile.
and then steps from 4) to 9) from the Toluidine Blue one. not step 8) it will be different u will say DNA stains red/black with acetic orcein so u should be able to see red/purple chromosomes against a pale pink background.

are you sure we need to know this?

 

[DANGERBP]

LOL yea all this
For orcein ethanoic stain:
1) put a test tube containing 2cm3 1M hydrochloric acid into a water bath at 60 degrees celcius
2) 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.
3) Put the root tips in a watch glass containing approx. 2cm3 of acetic alcohol for a minimum of 12 hrs.
4) Remove the root tips and place them watch glass containing approx. 5cm3 cold water. Leave for 4-5 mins. then dry on filter paper. It is important to blot the tips well to remove the water at this stage or a precipitate may form wen staining.
5) Put the root tips into a preheated hydrochloric acid for exactly 5 mins.
6) Repeat step 3). Handle the root tips gently as they will be fragile.
and then steps from 4) to 9) from the Toluidine Blue one. not step 8) it will be different u will say DNA stains red/black with acetic orcein so u should be able to see red/purple chromosomes against a pale pink background.

shit shit !!! no way am gonna b able to get all this in my frkkn mind !!! o.o
lol many thnks to you ! =p

 

[DANGERBP]

i dont think u really need 2 know this part... at least i haven't studied it... r u sure this is required?
if ur talking abt acetic orcein.... then there isnt any much difference, just the stain used is different...

okay i do hope its not but then how to answer to
Describe how you would prepare a root tip squash ?? =/