OCR Biology F212 Revision [3rd June 2013] (Now Closed)

What were the possible differences between Haemoglobin and Collagen

Damn!! I wrote myobacterium tuberculosis!


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I think I lost one or two marks on that, I realised last minute that the "water bear" was actually that microscopic organism on the insert...not an actual bear, silly me.

okay
i need some reassurance
for the 7 marker on phagocytes- i spoke about phagocytosis and chucked on the bit about antigen presenting at the end. i may just have said lysins instead of lysosomes but i cant remember exactly- how many marks would that be?

for the last question it said suggest and i didnt really look at the insert cos i was too good for it lol, but i wrote that speciation occurred only recently for the waterbear to be discovered- its a new species

for the calculations question i think i got like 0.801 or something.

for the biodiversity definition i said- the range of variation in organisms in a habitat
for the definitions for both eveneness and richness i wrote- in a habitat at the end of both

for the tb incidence question- i wrote lack of protection and condoms means people have hiv- more susceptible to tb
overcrowding in houses means they have a higher risk
and lack of ventilation means they have a higher risk

for the two tubes i put both at the bottom - what the heck was that?!

for meselson and stahl i put shake them at the same speed.
and use the same volume of solution in each tube
and use the same concentration of sugar solution

for importance of base pairing- i wrote it is needed for semi conservative. and it is also needed to make our proteins and characteristcs as mrna cant be made without it- as an exact copy of the coding starnd.

for sampling i wrote do it at different times, and repeat the procedure or standardize your procedure

the selective breeding question i wrote selecive brreeding for long term and antibiotics for short term.

for the reason why plants may be susceptible to disease (i think it was something like that - a one marker)- i wrote they dont have an advantageous characteristic or resistance because theyre more or less the same

for the one after that i wrote climate change means that selectively bred plants will produce less yields in different conditions as theyre made to perform best in specific conditions. some years wud have been optimum conditions, some years not.

Q1
Polypeptide(1)
H2NCHRCOOH (3)
Collagen is flexible(1)
Collagen:
3 polypeptide chains,linked by covalent bonds to fibres,left handed helix,1 in 3 amino acids is glycine(6)
Haemoglobin combine to oxygen to transport blood(1)
Haemoglobin:
Globular,4 polypeptide chains(3)

Q2
Enzymes(1)
Similar elements,similar bonds,similar shape which is complementary to the enzyme so can for enzyme-substrate complex.(3)
It can outcompete the -thing- so it is more likely to form an enzyme substrate complex with ethanol than with -thing-.This means that more ethanol will be broken down than -thing-(3)

Q3
Cells B and C(1)
As its the bodies response to a foreign antigen(1)
As it carries of phagocytosis on all cells.Doesnt involve lymphoctes(1)
Pinches pathogen into vehicle via phagoctosis.This pathogenic vehicle fuses with lysosomes which secrete enzymes breaking down the pathogen.Then the substances can be absorbed by the phagocyte via diffusion(7)

Genus name(1)
Order(1)
Phylum(1)
Animals(1)
Eukarya(1)
Phylogeny is study of evolutionary relationships.Allows us to see how closely relate two organism are via DNA similarities etc,so can be used to group organism based on similarities therefore helpfull in classification(3)
Too small to see with the eye as its only 2-3 mm long.Only discovered when microscopes were around(2)


A very rough start to an unofficial mark scheme
If we all add to this and improve this.
Marks next to answers represent marks avaliable and not marks gained by the answer next to it.

What amount of marks do you think will be 100UMS?

With the species evenness and richness could you just write the definitions?

Yes very good answers !


What was the question on phagocytes

What does everyone think A and B boundary will be?

Guys do you thin the exam companies look at these unofficial mark schemes and develop mark scheme so people get answers wrong? (For science exams)

uhhh i put primary structure for the first questions xD is that wrong?

Did you guys get around 0.6366 (or something like that) for the diversity index.