Biology Paper 6 ( ATP)

[Khadija.95]

uh

i don't think so ... no! multiplication in magn. is only when a number is given with the image and we multiply that number with our calculated magnification. otherwise its just drawing/image. if u still have any doubts please confirm it and post the right ans. here 2!

No no. I was wrong. I checked with Dr. Saira today. We don't multiply with hundred if they haven't already given us a magnification =)

 

[daredevil]

No no. I was wrong. I checked with Dr. Saira today. We don't multiply with hundred if they haven't already given us a magnification =)

=) glad i cud help =)

 

[daredevil]

what is bench solution?

 

[scouserlfc]

what is bench solution?

Its like some specific concentrations I dont think u are supposed to know it,its in the biuret test u could simply say add Biuret reagent and tell the test without going fancy with bench solution of CuSO4 and so on !

 

[daredevil]

Its like some specific concentrations I dont think u are supposed to know it,its in the biuret test u could simply say add Biuret reagent and tell the test without going fancy with bench solution of CuSO4 and so on !

thanks! i just wanted to know is all. i don't plan on getting fancy in my final O levels EXAM!!

 

[daredevil]

Its like some specific concentrations I dont think u are supposed to know it,its in the biuret test u could simply say add Biuret reagent and tell the test without going fancy with bench solution of CuSO4 and so on !

thanks! i just wanted to know is all. i don't plan on getting fancy in my final O levels EXAM!!

 

[scouserlfc]

thanks! i just wanted to know is all. i don't plan on getting fancy in my final O levels EXAM!!

Yeah same here keeping it simple and being composed is the key !
ANd no problem !

 

[sunflower789]

can somebody tell me wht experiment is done to find out tht chorophyl and carbondioxide are neccesary for photosynthesis??

 

[Fallen316]

can somebody tell me wht expweriment is done to find out tht chorophyl and carbondioxide are neccesary for photosynthesis??

for chlorophyll:
- take a well-watered, de-starched and VARIEGATED potted plant.
- leave the plant in sunlight for 8 hours.
- Remove one leaf and carry out the starch test.
- starch is made only in areas of the leaf where chlorophyll is present. Thus , chlorophyll is necessary for photosynthesis

for CO2:
- take two well-watered, de-starched potted plants.
- place one plant in a bell jar (JAR A) which is closed to prevent entry of Co2 and contains NaOH to absorb CO2.
- apply vaseline to seal bell jar on to the floor/glass plate
- tie a polythene bag over pot and around stem to prevent escape of Co2 from soil
- place the other plant in a bell jar (JAR B) which is open. (the control experiment)
- place both of them in sulight for 8 hours
- take a leaf from both plants and carry out starch test
- leaf in JAR A contains no starch while leaf in JAR B contains starch . Thus , CO2 is necessary for photosynthesis

HOPE I HELPED !!!

 

[sunflower789]

for chlorophyll:
- take a well-watered, de-starched and VARIEGATED potted plant.
- leave the plant in sunlight for 8 hours.
- Remove one leaf and carry out the starch test.
- starch is made only in areas of the leaf where chlorophyll is present. Thus , chlorophyll is necessary for photosynthesis

for CO2:
- take two well-watered, de-starched potted plants.
- place one plant in a bell jar (JAR A) which is closed to prevent entry of Co2 and contains NaOH to absorb CO2.
- apply vaseline to seal bell jar on to the floor/glass plate
- tie a polythene bag over pot and around stem to prevent escape of Co2 from soil
- place the other plant in a bell jar (JAR B) which is open. (the control experiment)
- place both of them in sulight for 8 hours
- take a leaf from both plants and carry out starch test
- leaf in JAR A contains no starch while leaf in JAR B contains starch . Thus , CO2 is necessary for photosynthesis

HOPE I HELPED !!!

thanks ALOT! it really did help
i hav another ques tht do we have to know about the experiment of demonstrating root pressure??

 

[Fallen316]

thanks ALOT! it really did help
i hav another ques tht do we have to know about the experiment of demonstrating root pressure??

i dont think so ..

 

[nightmaressana]

do we always have to draw a line or curve of best fit or when just asked to draw? please reply urgently

 

[sunflower789]

do we always have to draw a line or curve of best fit or when just asked to draw? please reply urgently

i think we draw it only when they ask for it...otherwise we just draw a smooth curve or straight line...i guess
someone plz correct me it im wrongg!

 

[Fallen316]

i think we draw it only when they ask for it...otherwise we just draw a smooth curve or straight line...i guess
someone plz correct me it im wrongg!

we draw it only when they ask for it... otherwise we connect the dots with a ruler or just draw a normal curve joining all points..
Corrected

 

[MAHmad]

How can we design experiments? like what cud be the steps in sequence 1, 2. .. :S

 

[MAHmad]

Also, how to make tables. Please help me :O

 

[sunflower789]

we draw it only when they ask for it... otherwise we connect the dots with a ruler or just draw a normal curve joining all points..
Corrected

lol thnx for correcting me and wait i wanna ask how do we draw a curve of best fit??i get lil confused at times :S

 

[Fallen316]

lol thnx for correcting me and wait i wanna ask how do we draw a curve of best fit??i get lil confused at times :S

like this
http://www.xtremepapers.com/community/attachments/untitled-png.9656/

 

[sunflower789]

like this
http://www.xtremepapers.com/community/attachments/untitled-png.9656/

ohhh ya....theres a question related to penicillin which i never understand how to answer
it goes like this


'Assume that:
• you are provided with a 10% solution of the antibiotic, penicillin, that is produced by this
fungus
• you have some Petri dishes containing a culture medium on which bacteria are growing,
forming a cloudy layer
• when the bacteria are killed by the penicillin a clear area shows on the plate
• the usual laboratory instruments are also available.

(b) Make an outline plan of an investigation to determine the minimum concentration of this
penicillin needed to kill the bacteria.'

 

[Fallen316]

ohhh ya....theres a question related to penicillin which i never understand how to answer
it goes like this


'Assume that:
• you are provided with a 10% solution of the antibiotic, penicillin, that is produced by this
fungus
• you have some Petri dishes containing a culture medium on which bacteria are growing,
forming a cloudy layer
• when the bacteria are killed by the penicillin a clear area shows on the plate
• the usual laboratory instruments are also available.

(b) Make an outline plan of an investigation to determine the minimum concentration of this
penicillin needed to kill the bacteria.'

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.