Biology Paper 62:What were the "Improvements" in experiment?

[Rashu712]

In Biology ATP Second Variant, we had a question on 4 improvement suggestions for the experiment of finding the concentration of Vitamin C.
I wrote these because I had nothing else come across my mind at that time.

1. Repeat the experiment for more accuracy.
2. Maintain a constant temperature.
3. Use a pipette or a burette to measure the volume of Iodine solution more accurately.
4. Wear gloves.

I'm doubtful about most of my points, but I could think of nothing else.

Also, for the first part of the first question, I got 0.1% for the concentration of Vitamin C on S3 sample.

Then from the bar chart, Blackcurrant had the most vitamin C from all other fruits. (even though I thought orange was rich in Vitamin C)


Also, how were we supposed to draw the magnified diagram of the annelid? It was for 5 marks and we were not supposed to label the parts.
I just did the enlarged drawing by about x1.04. And usually they give v3 marks for a magnified image and for labels. So I don;t get what I haven't done. I'm confused.

The percentage area of damaged leaf was 34.4% according o my calculation, so will there be a range for the answer?

 

[1bilalm]

Re: Biology Paper 62:What were the "Improvements" in experim

i also took varient 2
so for the first one i think ur very much right
for the second vitamin c thing i wrote the same 0.1 percent as u because 11 drops were added for s3 and 22 for s1 which was 0.2 so half
for the third one absolutely ur 100 percent right but how did u do the graph i mean what did u plot against x and y axis
for me the area thing was abut 20 percent but yeah tell me how u calculate it

 

[Rashu712]

Re: Biology Paper 62:What were the "Improvements" in experim

i also took varient 2
so for the first one i think ur very much right
for the second vitamin c thing i wrote the same 0.1 percent as u because 11 drops were added for s3 and 22 for s1 which was 0.2 so half
for the third one absolutely ur 100 percent right but how did u do the graph i mean what did u plot against x and y axis
for me the area thing was abut 20 percent but yeah tell me how u calculate it

Well it was a bar chart because there were different sets of data (Orange, Strawberry, Blackcurrant, Pineapple) and they were all tested on the same type of experiment, use of Iodine solution to reach the end point by counting the number of drops.

So the names of the fruits were on the x-axis and the number of drops were on the y-axis.

So you get a bar chart that compares the composition of Vitamin C for each type of data, I'm positive.

And Blackcurrant had the highest amount of Iodine Drops needed (48 drops) to reach the end point. And according to the experiment in the previous page, as the concentration increases, number of iodine drops needed to reach end point increases. So it must mean that Blackcurrant had the highest proportion of Vitamin C.

And about calculating the Percentage Suyrface Area affected by tunnels, you had to count the number of grids that occupies the leaf first to get the surface area of the leaf. I counted and my result was approximately 61 cm^2.
Then I counted the number of grids that had the damaged areas. That was approximately 21 cm^2.

Then to get the percentage,
21/61 x 100 = 34.4%

The answer will be different for different students because there's no correct way to get the actual answer. So I believe there will be a range for the percentage.

 

[angel786]

Re: Biology Paper 62:What were the "Improvements" in experim

well percentage area of damaged leaf was 30% according to my calculation so is this correct???

 

[Rashu712]

Re: Biology Paper 62:What were the "Improvements" in experim

well percentage area of damaged leaf was 30% according to my calculation so is this correct???

I think the range will be about 30% - 40% but I'm not sure.

 

[Rashu712]

Re: Biology Paper 62:What were the "Improvements" in experim

So what were the improvement suggestions?

 

[1bilalm]

Re: Biology Paper 62:What were the "Improvements" in experim

so that means i lose 3 marks for the percentage graph thing

 

[angel786]

Re: Biology Paper 62:What were the "Improvements" in experim

well percentage area of damaged leaf was 30% according to my calculation so is this correct???

I think the range will be about 30% - 40% but I'm not sure.

thanks