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Biology/Physics ATP Preparation Thread

J

Joker101

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hold an object in front of a light move lens to and fro until image formed on wall is very clear... distance between lens and wall is focal length

Light______O_____ <- L -> ________ W
 
S

Soulgamer

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Its easier if you make a tangent where the line hits the circle and make a normal perpendicular to the (line) tangent.
 
L

lionkill3r

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lol zain no offense but i think you are wrong. ask some teacher or something coz that middle piece is not the embryo.
Anyway you should not draw and label outer parts(testa) in the question. Are you sure bout da answer ???
 
adnanj

adnanj

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And someone now plz lOCK this thread.. over with these..! yuppeeeee..!! :lol: :ROFLMAO: :p :Bravo:
 
abcde

abcde

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May help candidates appearing in November or later so ease up on the anger! :p :)
 
adnanj

adnanj

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abcde said:
May help candidates appearing in November or later so ease up on the anger! :p :)
Click to expand...


but we r not angry.. and we r actually happy :D :Yahoo!:
 
Muhammad Talha

Muhammad Talha

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abcde said:
So am I. :D But I saw the 'mad' emoticon somewhere :p
Click to expand...
hahaha...it was me with mad emotion...i m happy bt i don't want to recall the papers i hv given thats y...so yes we can leave it open for other students... :D :D
 
S

Snowysangel

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intelnehalem said:
Tips on testing for Reducing Sugar/lipids/Protein/Starch
Starch:
Crush and grind a given solid sample
either you can make a solution with this or you can directly proceed to adding Iodine solution
Place the sample on a WHITE TILE (important!!)
Add Iodine SOLUTION (iodine disqualifies, it should be iodine solution)
Colour change:
red brown to blue black if starch is present

Reducing sugars:
Always for solutions only
If solid sample, crush and grind add 2cm3 of water and make a solution
Add equal amounts of Benedicts solution(if you have a 2cm3 solution, you have to add 2cm3 of benedicts )
HEAT over a WATER BATH
Colour change if reducing sugar is present:
blue to green/yellow/orange if only a little concentration of reducing sugar present in test solution
otherwise it is blue to BRICK RED PRECIPITATE!!

Proteins:
Add 2cm of Sodium/Potassium Hydroxide solution into the sample
Add a few drops of Copper sulphate solution using a pipette into the test tube containing the sample
If proteins are present:
Colour change is blue(due to Copper sulphate) to purple/mauve/lilac!

Lipids:
If it is a DRY solid, crush and grind the sample
Place it in a DRY test tube (have to be dry otherwise the experiment will be inaccurate)
add about 2cm3 of ethanol to the test tube containing the dry sample
pour ONLY THE LIQUID PART OF THE SAMPLE SOLUTION containing ethanol into another test tube containing 2cm3 of water!
If Lipids/fats are present, a cloudy EMULSION is formed

We tend to forget some of these minute details so I though of writing them down ! :D
Click to expand...

Why does the sample have to be kept in a dry test tube? How will that interfere with the test? I know it'll definitely give a white emulsion if the restive contains moisture, but why??
 
A

Aajinkya

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How can you measure the length of a spring in physics?
I mean springs have these circles at end, so do we do it from the top or what?
A detailed diagram would be appreciated! :)
 
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