Biology Paper 6 ( ATP)

[stareaj]

1. dilute the 10% penicillin to prepare various concentrations.
2. Soak the filter paper discs in different concentrations of penicillin
3. On the petri dishes where bacteria are growing, discs are placed after covering with lid, the plates are incubated at 37degrees for 24 hrs.
4. after 24 hrs the diameter of clear areas around discs is measured
5. Formation on clear areas determines the concentration of penicillin required to kill bacteria.

Thank youur a genius

 

[Fallen316]

Thank youur a genius

you're welcome

 

[Executor]

People go to this thread http://www.xtremepapers.com/community/threads/dua-for-all-candidates.14272/ and make dua for all those currently appearing in the exams. You will also find useful duas in it and Remember every share counts.

 

[sunflower789]

1. dilute the 10% penicillin to prepare various concentrations.
2. Soak the filter paper discs in different concentrations of penicillin
3. On the petri dishes where bacteria are growing, discs are placed after covering with lid, the plates are incubated at 37degrees for 24 hrs.
4. after 24 hrs the diameter of clear areas around discs is measured
5. Formation on clear areas determines the concentration of penicillin required to kill bacteria.

wow niceee...you know so much about this complicated stufff

 

[Mohammed Hassan Gaafar]

For paper 6 just read all the expirements u have taken in the syllabus and 100% he will ask from them addition to that u must know how to draw perfectly if u are not a good drawer it will be better to divide the picture given into squares and then draw bigger squares in the area provided and copy it and it will be enlarged but this will take time, next is the magnification which is = DRAWING/ACTUAL u just take any length from the drawing you made and divide it by the crossponding length of the drawing given and in the graphs you should know how to know the difference between the bar chart, histogram and line graph.
FOR NOW memorize the expirements quickly and solve past papers as much as you can and dont forget to time your self and if u exceeded the time try to finish before the time by 20-25 minutes to have time to revise in the IGCSE EXAM,... WELL I HOPE THIS GIVES YOU AND IDEA ABOUT WHAT TO DO AND TO ALL XTREMEPAPERS VISITORS AND INSHALLAH WE WILL ALL GET A* (Pray for me)

 

[SALT]

HEY I NEED URGENT HELP.......HOW DO U TEST THE PRESENCE OF STOMATA??
PLZ REPLY QUICK!

 

[Fallen316]

HEY I NEED URGENT HELP.......HOW DO U TEST THE PRESENCE OF STOMATA??
PLZ REPLY QUICK!

- place a leaf between 2 pieces of dry cobalt chloride paper and sandwich the leaf between them held in position by rubber bands.
- note the colour of the papers
- it turns pink because it comes in contact with water vapours which diffuse out of the leaf through stomata.

 

[Fallen316]

wow niceee...you know so much about this complicated stufff

to be honest, this is not complicated

 

[SALT]

Fallen316.......really? isnt tht to compare the rates of transpiration of the upper nd lower surfaces of the leaf??my book says so
there is a separate test given to test the presence of stomata which i cant get!

 

[Fallen316]

Fallen316.......really? isnt tht to compare the rates of transpiration of the upper nd lower surfaces of the leaf??my book says so
there is a separate test given to test the presence of stomata which i cant get!

this experiment is also used for that too.
for e.g the same experiment is used to show that animals use o2 during respiration and give out CO2 while respiration.
one experiment can be used to proof two things.

 

[SALT]

Fallen316

k....thnx,but do u kno the other one?

 

[Fallen316]

k....thnx,but do u kno the other one?

nup, i dont.

 

[Mohammed Hassan Gaafar]

HEY I NEED URGENT HELP.......HOW DO U TEST THE PRESENCE OF STOMATA??
PLZ REPLY QUICK!

By applying a Nail Vanish in the bottom of the leaves
And then stick a tape to it
Remove the tape and this will remove the lower epiderm of the leave
Test it under a light microscope and count the number of stomata in 3 different views
Repeat and take the average

 

[Oishee Asif]

Good luck to all. c: <3

 

[Vogue]

does bieuret reagent only tests proteins or it also gives a positive result wid amino acids?

 

[malay]

does bieuret reagent only tests proteins or it also gives a positive result wid amino acids?

don't know about the amino acid but if peptons are present it goes pink from blue

 

[malay]

Auxins are the growth hormones in plants. They are produced at the tips of the plant shoots. They cause the elongation of the cells and cause growth.
In positive phototropism, the auxins accumulate at the side of darkness leading to rapid growth in this side. This causes the shoot to grow inthe direction of light. In negative geotropism the auxins accumulate at the side of the darkness but the high concentration of auxins inhibit the growth in this side. Therefore the root grows away from light. In the positive geotropism, the auxins accumulate at the side of gravity. It inhibits growth at this side causing the growth at the opposite side bending of root towards gravity. In the negative geotropism, the auxins accumulate at the lower side of the shoot causing growth in this side leading to the bending of the shoot away from gravity.
They are used as weed killers, used in food processing industry to prevent the bananas from ripening, growth of sugar cane at low temperature. Another use of auxins is in root cutting. The grower cut off apiece of parent plant and dip its base into a hormone rooting powder and place it in damp compost. The powder contains auxin which stimulate new roots to grow from the cut stem and the newly formed plant has the same characteristics as the parent plant.

I hope this helps you daredevil!

dis is sooo confusing ....btw i don't think so dis is in our syllabus??

 

[malay]

auxins are not a part of the course

YESSSSHHHHH

 

[muhammadrafay]

how was your paper

 

[malay]

how was your paper[/quot
it was pretty easy ...went well