Biology; Chemistry; Physics: Post your doubts here!

[exploded diper]

Okay let's start discussing Biology ATP.
Describe two experiments that demonstrate how water is carried up the plant.
Describe two experiments to show the presence of stomata on the underside of the leaves.

1) take a (balsam) plant and put it in beaker of dyed water ( with ink) .... after a few hours cut a tranverse section of the stem .. the xylem will be coloured showing water goes up through the xylem.....
2)cut a shoot of an actively growing potted plant leaving 5cm of the stem over the soil.........fit a glass tubing ..to the cut end of the stem by means of rubber tubing ....partialy fill the glass tubing with water ..and support it with a retort stand mark the level of the water after a few hours it will rise.....showing tht water moves up by root pressure....is this correct?

 

[***amd***]

Okay let's start discussing Biology ATP.
Describe two experiments that demonstrate how water is carried up the plant.
Describe two experiments to show the presence of stomata on the underside of the leaves.

Describe two experiments that demonstrate how water is carried up the plant.
add any soluble dye (suppose its Blue) in the water in a beaker. take a small germinating plant and put it in the beaker with its roots dipped in the beaker. leave it there for 2 hrs. after it, when you cut thee plants stem and roots, u'll see their xylem tissues stained with the dye. am i right?
i dont know the other experiment .-.
Describe two experiments to show the presence of stomata on the underside of the leaves.
select a leaf from a plant. put a sheet of paper, soaked in cobalt chloride ppr, on the upper side of leaf and one on the lower side. press them tight by putting glass slides over them and tightening them with strings/rubber bands. after some time, you'll see the colour of lower ppr changing from blue to pink. this is because of the water being released from stomata pores on the lower surface. the ppr on upper surface will remain intact.

 

[***amd***]

Describe an experiment that relates force, mass and acceleration

TUKKA :-
take an object of a constant mass, push it along the table. the more u push (the more u apply force) the more will be its acceleration.
so we conclude, F is directly proportional to acc., with a constant mass

 

[exploded diper]

TUKKA :-
take an object of a constant mass, push it along the table. the more u push (the more u apply force) the more will be its acceleration.
so we conclude, F is directly proportional to acc., with a constant mass

and u can add light gates to measure the acceleration

 

[exploded diper]

Describe two experiments that demonstrate how water is carried up the plant.
add any soluble dye (suppose its Blue) in the water in a beaker. take a small germinating plant and put it in the beaker with its roots dipped in the beaker. leave it there for 2 hrs. after it, when you cut thee plants stem and roots, u'll see their xylem tissues stained with the dye. am i right?
i dont know the other experiment .-.
Describe two experiments to show the presence of stomata on the underside of the leaves.
select a leaf from a plant. put a sheet of paper, soaked in cobalt chloride ppr, on the upper side of leaf and one on the lower side. press them tight by putting glass slides over them and tightening them with strings/rubber bands. after some time, you'll see the colour of lower ppr changing from blue to pink. this is because of the water being released from stomata pores on the lower surface. the ppr on upper surface will remain intact.

can we do this : take a leaf from a plant and coat the top of the leaf with petroleum jelly and then dip it in a beaker full of water ... and put it in sunlight... .... after a few minutes bubbles will appear to be coming from the lower side of the leaf showing the presence of stomata

 

[exploded diper]

Describe two experiments that demonstrate how water is carried up the plant.
add any soluble dye (suppose its Blue) in the water in a beaker. take a small germinating plant and put it in the beaker with its roots dipped in the beaker. leave it there for 2 hrs. after it, when you cut thee plants stem and roots, u'll see their xylem tissues stained with the dye. am i right?
i dont know the other experiment .-.
Describe two experiments to show the presence of stomata on the underside of the leaves.
select a leaf from a plant. put a sheet of paper, soaked in cobalt chloride ppr, on the upper side of leaf and one on the lower side. press them tight by putting glass slides over them and tightening them with strings/rubber bands. after some time, you'll see the colour of lower ppr changing from blue to pink. this is because of the water being released from stomata pores on the lower surface. the ppr on upper surface will remain intact.

the colour on the top may change a little too...

1)take a potted plant and cover it with polythene bag till the stem... put the plant in a bell jar in strong sunlight for a few hours.... after a few hours test the liquid on the inside of the bell jar...we can test the the condensed vapour by cobalt chloride paper which will turn from blue to pink......

 

[***amd***]

can we do this : take a leaf from a plant and coat the top of the leaf with petroleum jelly and then dip it in a beaker full of water ... and put it in sunlight... .... after a few minutes bubbles will appear to be coming from the lower side of the leaf showing the presence of stomata

why do we need to oat the upper surface with petroleum jelly?

 

[exploded diper]

why do we need to oat the upper surface with petroleum jelly?

to show tht the lower surface contain stomata...........

 

[***amd***]

to show tht the lower surface contain stomata...........

but upper surface already has cuticle on it to work as a wax.

 

[funky brat]

but upper surface already has cuticle on it to work as a wax.

Actually it is not a hard and fast thing that stomatas are present only on the upperside for example in grasses so it would better to coat it with wax to increase the reliablility of results.

 

[Awesome12]

What is the experiment to demonstrate root-pressure?

 

[exploded diper]

You're so curious to know a question in the paper.

yeah.....maybe i am......

 

[exploded diper]

What is the experiment to demonstrate root-pressure?

the one i just explained is to demonstrate root pressure...........

 

[Faizan Muhammmad]

Guys any of you worried about drawing part?
My drawing is really bad

 

[kirann]

its a smooth curve ....cutting most of the points.......u can skip the points but if u skip two points one must be above the curve and the other below....

Y
Yes i know this, i can skip points in a line of best fit but how can i do this with the curve..

 

[Awesome12]

the one i just explained is to demonstrate root pressure...........

Which one. You have posted so many

 

[exploded diper]

Which one. You have posted so many

this one
cut a shoot of an actively growing potted plant leaving 5cm of the stem over the soil.........fit a glass tubing ..to the cut end of the stem by means of rubber tubing ....partialy fill the glass tubing with water ..and support it with a retort stand mark the level of the water after a few hours it will rise.....showing tht water moves up by root pressure...

 

[Awesome12]

this one
cut a shoot of an actively growing potted plant leaving 5cm of the stem over the soil.........fit a glass tubing ..to the cut end of the stem by means of rubber tubing ....partialy fill the glass tubing with water ..and support it with a retort stand mark the level of the water after a few hours it will rise.....showing tht water moves up by root pressure...

Why do we have to put it above the soil?

 

[exploded diper]

Why do we have to put it above the soil?

the plant stays inside only a part of it must be above the soil........

 

[Awesome12]

the plant stays inside only a part of it must be above the soil........

WHY?