Qualitative biology ocr!!! As!!

I've got mine on Wednesday but half my year has already done it. As far as I'm aware the questions are fairly simple and you should get them if you've listened through the year. I think there's some theory-based questions around water potential; what would happen if you put the leaf cells into high and low concentration solutions.

As far as the actual practical goes, all you have to do is put a lettuce in a water bath with an enzyme that digests the cell wall, keep it at a constant temperature and then draw a few different views from a microscope. Make sure you know how to prepare a slide and draw an image.

Good luck!

Edit: Just found this from another post:

"One of them was to draw a lettuce cell displaying the chloroplasts (3 marks)
One was about why you had to warm the water before adding enzyme (1 mark) ( enzymes work at optimum temperature)
one mark for practical
2 marks - why the shape of the cell changed from rectangular to circular - to do with lysis
3 marks- this was about osmosis, and how different concentrations would affect it"


Also, we had a prep session where they covered how to draw things, to summarise:
- Use clear continuous lines
- Draw everything in pencil
- Use ruled lines for labels
- Don't shade
- Use at least half of the available space
- Use a sharp pencil

The system they use to mark it means you lose marks for not doing any of the above, rather than gaining marks for doing them, so be sure to know what you're doing before you go into the exam

So we don't need to draw table for qualitative ?

It breaks down the cell wall, more specifically the cellulose or pectin, so you can suggest that the enzyme is cellulase or pectinase. It does tell you briefly at the start of the paper so if you forget just use your logic and you'll be fine

Thank you so much for the help ������ so how does the water diffuse across if the cell wall is broken down does it just pass through?

I've got mine on Wednesday but half my year has already done it. As far as I'm aware the questions are fairly simple and you should get them if you've listened through the year. I think there's some theory-based questions around water potential; what would happen if you put the leaf cells into high and low concentration solutions.

As far as the actual practical goes, all you have to do is put a lettuce in a water bath with an enzyme that digests the cell wall, keep it at a constant temperature and then draw a few different views from a microscope. Make sure you know how to prepare a slide and draw an image.

Good luck!

Edit: Just found this from another post:

"One of them was to draw a lettuce cell displaying the chloroplasts (3 marks)
One was about why you had to warm the water before adding enzyme (1 mark) ( enzymes work at optimum temperature)
one mark for practical
2 marks - why the shape of the cell changed from rectangular to circular - to do with lysis
3 marks- this was about osmosis, and how different concentrations would affect it"


Also, we had a prep session where they covered how to draw things, to summarise:
- Use clear continuous lines
- Draw everything in pencil
- Use ruled lines for labels
- Don't shade
- Use at least half of the available space
- Use a sharp pencil

The system they use to mark it means you lose marks for not doing any of the above, rather than gaining marks for doing them, so be sure to know what you're doing before you go into the exam

Thank you so much! Do you have any tips on how to do the drawing? We were told not to shade in anything, use a sharp pencil and don't let your arrows cross, but is there anything specific to the lettuce cell that you need to draw? Do you just draw one cell or more, and do you include organelles that you can see or is it just an outline? Thanks