Biology paper 52

[samantha liyanage]

yep it's used when it's continuous and comparing 2 means.

 

[samantha liyanage]

in q1
we're supposed to find the area of the brown area.
by keeping the enzyme solution in the well to find out the unknown concentration using c1v1=c2v2

 

[Princess Raven]

in q1
we're supposed to find the area of the brown area.
by keeping the enzyme solution in the well to find out the unknown concentration using c1v1=c2v2

I did that but some ppl are saying we have to draw a graph..I hope u are right

 

[samantha liyanage]

you can find it out using the graph aswell
both ways are fine

 

[anonymous1122]

you can find it out using the graph aswell
both ways are fine

I wrote to prepare concentrations and compare the area stained with the area stained by the extract
Is that fine? :/

 

[samantha liyanage]

that does sound right.
But, the concentrations we might find may not be the concentrations we're preparing so then we might have a problem with comparing the the two areas :/

 

[anonymous1122]

that does sound right.
But, the concentrations we might find may not be the concentrations we're preparing so then we might have a problem with comparing the the two areas :/

Plot a graph with the values would lead to concentration no? ._.

 

[samantha liyanage]

sort of i guess :')

 

[Jassim]

Threshold about 24-25, highest in recent years for sure, I'm guessing. It was very basic, nothing tricky at all.
Its very clearly the T-test, the reason being that the data was continuous and even a normal distribution curve could be obtained. Plus, they even gave upper and lower limits, but don't worry too much, that part was like 2 marks only.

 

[anonymous1122]

Threshold about 24-25, highest in recent years for sure, I'm guessing. It was very basic, nothing tricky at all.
Its very clearly the T-test, the reason being that the data was continuous and even a normal distribution curve could be obtained. Plus, they even gave upper and lower limits, but don't worry too much, that part was like 2 marks only.

2 marks but still i think i might lose 2-3 more here and there like in explanation question so :/
What was the procedure you wrote for 8 marks in q1?

 

[Jassim]

I did that but some ppl are saying we have to draw a graph..I hope u are right

You could draw a graph as well for accuracy and illustrating the results of the investigation, but the principle factor was the size of the area that got stained due to concentration of amylase in the extract you placed in the wells.

 

[Jassim]

2 marks but still i think i might lose 2-3 more here and there like in explanation question so :/
What was the procedure you wrote for 8 marks in q1?

Waaay too long to explain, but basically had to compare sizes of stained areas that students got, and compare all results with the control of 0.5 g per mol of amylase. Theres so much more but too lazy to type

 

[anonymous1122]

You could draw a graph as well for accuracy and illustrating the results of the investigation, but the principle factor was the size of the area that got stained due to concentration of amylase in the extract you placed in the wells.

Is comparison method correct? To prepare concentrations of amylase and calculate area. The area of concentration prepared corresponding to area stained by fungal extract is the required concentration?

 

[Jassim]

Is comparison method correct? To prepare concentrations of amylase and calculate area. The area of concentration prepared corresponding to area stained by fungal extract is the required concentration?

The question was whether the size of stained area was proportional to concentration of amylase. You couldn't calculate the exact concentration, but you had to find the relative trend when you increased/decreased the concentration, and to calculate the size of area you would need the diameter and radius, and surface area, of the plate, of the well, and the stained area and find the difference in them also using the formula pi r^2.
You could replicate the experiment using 4 or more different types of fungi which would have a different concentration of amylase to cross-check whether the proportionality trend obtained by the students was reliable too.

 

[Omar Haider]

I said to dilute the initial stock sample (because the independent variable was amylase concentration) and then find the area stained with each dilution. Plot the graph of the results. Then carry out the same experiment from the amylase from the yeast extract. For the given area (from the yeast extract), create construction lines on the graph and thus find the concentration of the amylase.

 

[anonymous1122]

The question was to find unknown concentration of amylase in the extract of fungus.
And we didnt have to verify the trend. The trend given was suppose to be used in calculating the concentrations.

Threshold is gonna be 21-23 because this question was a bit tricky.

 

[anonymous1122]

I said to dilute the initial stock sample (because the independent variable was amylase concentration) and then find the area stained with each dilution. Plot the graph of the results. Then carry out the same experiment from the amylase from the yeast extract. For the given area (from the yeast extract), create construction lines on the graph and thus find the concentration of the amylase.

Exactly! The comparison method. I didnt mention graph but we could find compare areas for the concentration.

 

[aka abdul]

I forgot to compare the area of stained region with the amylase from fungal cells .how many marks could I loose for this ?

 

[anonymous1122]

I forgot to compare the area of stained region with the amylase from fungal cells .how many marks could I loose for this ?

Max 1 or no marks deducted
Provided you covered other experimental points.

 

[aka abdul]

n secondly why did the activity of amylase solution decreased in different extract in q1