BIOLOGY PRACTICAL P33

[daviruss]

HOW WAS THE PRACTICAL PEOPLE :")
DID THE ONION MAKE YOU CRY

 

[mariyam95]

easy good bt the last question was a nytmare

 

[daviruss]

the percentage question ? btw the graph was a bar chart right ?

 

[samwickz]

the percentage question ? btw the graph was a bar chart right ?

really cuz i got a normal decreasing graph!

 

[Aarjit]

the percentage question ? btw the graph was a bar chart right ?

It was a SIGMOIDAL graph. How do expect candidates to calculate the [NaCl] when 50% erythrocytes were destroyed from a BAR graph? We were plotting a cumulative frequency curve.

 

[DARK DRAGON]

what were the improvements for onion experiment?

 

[samwickz]

what were the improvements for onion experiment?

i wrote add a dye not sure wbt u?

 

[Abhaya Poudel]

i wrote add a dye not sure wbt u?

I did write so, the onion must be stained with some dye to observe the clear plasmolysis.

 

[DARK DRAGON]

i wrote add a dye not sure wbt u?

i wrote do serial dilution to get diferent concentrations , make sure onion is from same plant and use more onion epidermis for each concentration.

is that right?

 

[samwickz]

i wrote do serial dilution to get diferent concentrations , make sure onion is from same plant and use more onion epidermis for each concentration.

is that right?

same here i kinda wrote abt d wide range of conc part tooooooooo

 

[Aarjit]

what were the improvements for onion experiment?

>> using narrower ranges of concentrations to obtain accurate [unknown];
>> using a fast dye (safranin red, methylene blue, fast green, I2 in KI);
>> The onions must be placed in their respective solutions for the same period of time.

 

[DARK DRAGON]

what about how to make it accurate? i wrote make sure time between mounting and observing is the same and use the same number of drops.
for the last question i got 7.55 micrometer for width of cell u?
and when anotating the diagram where did u put the egg yolk? i put it between the water and oil.

 

[Aarjit]

You're correct.
The range for the mean diameter of erythrocytes is ~ 6.0 to 8.0 um; but since the cells underwent lysis, the mean should be < 8.0 um (standard diameter of a turgid erythrocyte).

 

[daisy1234]

what?i drew a large rbc and got a 37.8um.
I drew the rbc and wbc of the same sizes.is that okay?

 

[daisy1234]

and what do you guess the grade threshold to be around?reply asap!:/

 

[samwickz]

what about how to make it accurate? i wrote make sure time between mounting and observing is the same and use the same number of drops.
for the last question i got 7.55 micrometer for width of cell u?
and when anotating the diagram where did u put the egg yolk? i put it between the water and oil.

yeppy i got 7.6 coooooooooooooool

 

[DARK DRAGON]

what?i drew a large rbc and got a 37.8um.
I drew the rbc and wbc of the same sizes.is that okay?

U were suppose to measure the length of red blood cell on the diagram and use the magnification to find the actual width

drawing same size is NOT ok

 

[samwickz]

hay how did u guys draw the emulsion thingy did yall draw water?

 

[OakMoon!]

You can't add a dye. There is a reason why they didn't give us iodine in the first place. Because that will further cause error in the experiment. The concentration of dye will also have to be taken into account, as that will effect the water potential of the surroundings. So dye was not a possibility.

 

[OakMoon!]

what?i drew a large rbc and got a 37.8um.
I drew the rbc and wbc of the same sizes.is that okay?

You didn't have to take the measurement of the drawing. You just had to show in the drawing and nothing else.

Since it was one image, the dimensions of the drawing should have been in the same ration as that in the picture.