2016 OCR Biology A Breadth - Unofficial Mark Scheme

Does anyone disagree with my logic here for the evidence one on the back page? Can't remember the precise wording or letters attributed to the evidence.

Evidence that it's an active process
- Metabolic inhibitors stop translocation (i.e. it requires energy to take place, poisons prevent this energy production and therefore it will stop).
- High temperatures stop/slow the process (requires carrier proteins to load the phloem).

Evidence that it's from source to sink
- Whichever one said they import the assimilates was probably a good shout.
- T'other one.

Irrelevant (i.e. not written in answer)
- **** the aphids, they prove cock all. (it only told you they can be used to analyse sap in the phloem vessel).
- The one about movement from leaf into vessel (sure, it goes into a vessel, nothing about the net movement in this context is suggested though).

roast me

answers to multiple choice

Q. about similarity between eukaryote and prokaryote = ribosomes

Q. about stage of cell shown = metaphase

q. about inhalation = C

Q. about pathogens was athletes foot

q. about 'how are polynucleotide chains held together' = phosphodiester bonds between sugar and phosphate groups maintain the sugar phosphate backbone and the chains are held together by hydrogen bonds in base pairing. A - T , C - G. there are 3 hydrogen bonds between C and G and 2 between A and T. These keep the chains together.

What about the fake cell with the extra cellular fluid?

What about the fake cell with the extra cellular fluid?

Wtf even was that question

Root hairs with further extentions to the norm to increase surface area and overall expoure to the soil along with a high water potential in the cell to increase the water potential gradient and draw water inwards

What was the answer for the roots getting water from soil with low water potential?

For the ways in which zoos can help in preservation efforts, i said to educate the public to make them aware of the issues surrounding the rhino. Do you think this would be worthy of credit?

Root hairs with further extentions to the norm to increase surface area and overall expoure to the soil along with a high water potential in the cell to increase the water potential gradient and draw water inwards

I said mineral ions are actively pumped in to the root hair to lower the water potential( so it has an even lower water potential than the soil), and as a result, water would move from the soil into the root hair from high to low water potential, not sure if it's right tho

I said mineral ions are actively pumped in to the root hair to lower the water potential( so it has an even lower water potential than the soil), and as a result, water would move from the soil into the root hair from high to low water potential, not sure if it's right tho

I don't know mate, I related it to ex situ conservation, I imagine that would be the safest option, because they said that captive breeding didn't work out in the question.

For the ways in which zoos can help in preservation efforts, i said to educate the public to make them aware of the issues surrounding the rhino. Do you think this would be worthy of credit?