Biology; Chemistry; Physics: Post your doubts here!

[DaniyalK]

how do you write ionic equations, i mean i looked it up in the book but i didnt get it, can anyone explain it to me please. in an easy manner, because im dumb.

Have you studied it from Chemistry Matters? That explains it well imo.

 

[Faizan Muhammmad]

Oh, you mean Faizan Muhammad.

whatever gave you this idea?
I barely know you, you barely know me

 

[Dark Destination]

whatever gave you this idea?
I barely know you, you barely know me

Lol, not you.
I confused your name with him. Nevermind. xD
Mohammad Farzanullah got a world distinction in maths. Not you.

 

[Faizan Muhammmad]

Lol, not you.
I confused your name with him. Nevermind. xD
Mohammad Farzanullah got a world distinction in maths. Not you.

yeah mairee itnee auqat kahan

 

[exploded diper]

yeah mairee itnee auqat kahan

we all know tht

 

[exploded diper]

yeah mairee itnee auqat kahan

just jking.....

 

[exploded diper]

Assume Y has a Voltage of 200 V so From Y the electrons flow to plate 2 .ok? that you can undertstand but the Plate 1 will have 0 voltage against it so it will attract the electron toward itself i.e point X

r u giving papers this year or not.........?

 

[funky brat]

r u giving papers this year or not.........?

He's in A1.

 

[exploded diper]

He's in A1.

oh....cool stuff....

 

[exploded diper]

how to prepare a microscope slide..
for animal cell(10)
for plant cel(10)
basically eed to know thoroughly how to prepare a slide

 

[Awesome12]

how to prepare a microscope slide..
for animal cell(10)
for plant cel(10)
basically eed to know thoroughly how to prepare a slide

10 marks!!!
I saw it as a max of like 4 in the paper
This is for a plant cell

 

[exploded diper]

10 marks!!!
I saw it as a max of like 4 in the paper
This is for a plant cell

View attachment 40203

i saw it in a past paper for 1o marks,,,,,,,,

 

[Awesome12]

i saw it in a past paper for 1o marks,,,,,,,,

They must have been vintage past papers

 

[funky brat]

i saw it in a past paper for 1o marks,,,,,,,,

10 marks!!!
I saw it as a max of like 4 in the paper
This is for a plant cell

View attachment 40203

These points can be made upto 10 marks by explaining each briefly.

 

[exploded diper]

These points can be made upto 10 marks by explaining each briefly.

would u mind explaining briefly.....

 

[exploded diper]

They must have been vintage past papers

it was in 2006...and to check for cholorplast presence...i guess....

 

[exploded diper]

before statring ethanol emulsion test y do u make sure tht the ethanol test tube is dry...
and y is ethanol added before water....

 

[funky brat]

10 marks!!!
I saw it as a max of like 4 in the paper
This is for a plant cell

View attachment 40203

exploded diper here you go!

1. First add a few drops of water or solution on the microscope slide to avoid dryness and wilting
2. Take a small piece of onion and using forceps (tweezers), peel off the membrane from the underside (the rough side).
3. Lay the membrane flat on the surface of the slide
4. Using a pin, lower a thin glass cover slip or cover glass onto the slide. Make sure there are no air bubbles
5. Looking from the side (NOT through the eyepiece), lower the tube using the coarse focus knob until the end of the objective lens is just above the cover glass. Do this carefully so as not to crack the cover glass (and possibly damage the objective lens)
6. Now look through the eyepiece and turn ONLY the smaller, fine focusing knob to move the optical tube upwards until an image comes into focus. The cells should look something like lizard skin.
7. Swap the objective lens for a higher powered one so that you can see the cells at greater magnification. You should be able to make out a nucleus in each cell.
8. Repeat the process after adding a dye solution (iodine or methylene blue). Be very careful; these dyes can stain your skin and clothes.#copied. You may add that the section should be as thin as possible for clearer observation under the microscope.

 

[exploded diper]

exploded diper here you go!

1. First add a few drops of water or solution on the microscope slide to avoid dryness and wilting
2. Take a small piece of onion and using forceps (tweezers), peel off the membrane from the underside (the rough side).
3. Lay the membrane flat on the surface of the slide
4. Using a pin, lower a thin glass cover slip or cover glass onto the slide. Make sure there are no air bubbles
5. Looking from the side (NOT through the eyepiece), lower the tube using the coarse focus knob until the end of the objective lens is just above the cover glass. Do this carefully so as not to crack the cover glass (and possibly damage the objective lens)
6. Now look through the eyepiece and turn ONLY the smaller, fine focusing knob to move the optical tube upwards until an image comes into focus. The cells should look something like lizard skin.
7. Swap the objective lens for a higher powered one so that you can see the cells at greater magnification. You should be able to make out a nucleus in each cell.
8. Repeat the process after adding a dye solution (iodine or methylene blue). Be very careful; these dyes can stain your skin and clothes.#copied. You may add that the section should be as thin as possible for clearer observation under the microscope.

thx man

 

[Awesome12]

before statring ethanol emulsion test y do u make sure tht the ethanol test tube is dry...
and y is ethanol added before water....

The test tube must be dry because any water or chemicals in the test tube may affect the experiment and consequently the result
Ethanol emulsifies fats (fats are soluble in ethanol). If we added water first, then there would be no reaction. When the lipids dissolve in ethanol, they will precipitate in water