Well I made this thread as we have recently started on Unit 2 and surprisingly noone has made the thread for the AQA Biology exam. Unit 2 Biology seems to be smaller in content than Unit 1 & past pupils from my college seemed to do better on Unit 2 than 1.
I made this for anyone to share their ideas and work together and prepare for the Bio2 exam. Sharing revision notes and strategies.
I have provided some links below that can help you with revision and learning the content, most of it is just for AQA but theres the odd link where the stuff on there overlaps to another specification. This shouldn't be an issue .
All the best -Ahmed (AD) Official exam papers for practice: (Here)
UNIT1 (BIO1 THREAD) Click here to navigate ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unofficial Markscheme - [NOTE] - Wasnt made by me
Quote me to edit certain parts although I am revising for chem2 atm
[QUOTE]BIOL2 JUNE 2014 UNOFFICIAL MS: Note: not all of the answers, only the ones i could remember. Hardest BIOL2 paper in my opinion
1) a) Define hierarchy: (1) - Groups within groups - No overlap between groups
b) How many families: (1) - 3
c) Name the phylum: (1) - Starts with C i think named Chordata, (vertebrate)
d) Independent segregation: (2) - Shuffling of maternal and paternal chromosomes - leads to new/different combinations of alleles - pair of chromosome line along equator in random orietation
2a) Selective Breeding: (1) way of improving species of crop or animal by breeding with individuals for desires/best charactersitics
b) Explain: (2) - reduces genetic diversity - as alleles chosen - best alleles rejected - leads to alleles for unfavourable characteristics being bred out of population
c) not sure
d) Describe the SD data; (2) - SD shows spread of data around mean - SD's do not overlap so differences are significant i.e not due to chance
3) a) This will be the MS answer for countercurrent system: - Water and blood flow in opposite directions/counter-current; - maintains concentration gradient (along gill) /equilibrium not reached; - As water always next to blood with lower concentration of oxygen;
b) Seal features: (2) B] - Flat body surface thus small surface area to vol ratio - less heat lost - blubber for insulation
c) AGH thickness of lamellae: (2) - longer diffusion pathway - smaller SA:Vol ratio
6 marker: How DNA is related to its function, i put: - stable molecule due to its double helix - strong due to the strong covalent bonds in sugar phosphate backbone - complementary base pairing allows DNA to replicate itself when needed and pass on genetic info - DNA is a long molecule, coiled very tightly thus store large amounts of genetic info - has a precise genetic code, determined by sequence of bases which controls protein synthesis - double helix protects the hydrogen bonds, thus prevents code being corrupted - has 4 bases (named) so can code info in any order
Immunological Techniques: (3) - Inject blood serum/protein from A into B - Obtain antibodies - Obtain antibodies from B and place into C - More closely related species = more precipitate, more similar antigens and more antigen-antibody complexes
Gibbons least closely related to humans: (2) - highest mean decrease in separation - fewer hydrogen bonds - shares fewer complementary bases
HSW Double blind trial (2): a) - prevents vested interest from scientists - prevents bias from scientists - prevents psychological effects from volunteers
b) question after that ^ regarding why different people had different antibody concentrations (2): - different amounts absorbed - differences in metabolic rates
There was one which asked to suggest a reason for the vaccine reducing the amount of smokers
My answer was - the vaccine alters the amino acid sequence responsible for creating the protein which the nicotine binds to. This alters its primary structure which leads to changes in the hydrogen/disulfide/ionic bonds, leading to alterations in the tertiary structure. As a result, the nicotine can no longer bind to the protein, so the chemicals aren't released so people see no point in smoking and stop.
Another question asked why the antibiotics shouldn't be given in higher doses.
I said about a mutation occurring which produces a resistant gene/allele which can be passed on between differebt species by means of horizontal gene transmission as the plasmid is transferred via a conjugation tube. It can also be passed between members of the same species by vertical gene transmission, leading to a higher frequency of the resistant gene and a larger population of resistant bacterium My opinion is that the grade boundaries are going to be very very low
My predictions Full UMS - 67/68 A - 53 B - 47 C - 42 D - 38 E - 32
Was attempting a question in the Nelson thornes book and I dont understand how to get the write answer.
Oage 127 Q2) In a population of men the systolic blood pressure shows a normal distribution. The mean of the population is 125 and the standard deviation is 10. If the population was 1000, how many of them have a blood pressure between 115 & 135
Hi just want to ask if anyone knows if we have to learn about Okazaki fragments and DNA ligase in DNA replication for AS? Because we learned about it anyway in our lessons but I don't see it on the specification
I'm really enjoying BIO2 so far, i'm finding it generally easier that BIOL1. I've done classification, variation, and DNA. DNA is the hardest thing to remeber so far.
Has anyone done a Biology PSA based on Unit 2? any idea what to expect? I have mine on friday - doing a distance course and my tutor has been less than helpful so far!
I'm really enjoying BIO2 so far, i'm finding it generally easier that BIOL1. I've done classification, variation, and DNA. DNA is the hardest thing to remeber so far.
Oh great, Im finding it a lot easier aswell...& its more interesting that Unit 1 it seems to me. We have nearly finished now we only have 2 chapters left.
Has anyone done a Biology PSA based on Unit 2? any idea what to expect? I have mine on friday - doing a distance course and my tutor has been less than helpful so far!
Sweet is that the real EMPA or just doing the PSAs for the EMPAs.....We did one of the PSAs, Transpiration pull using a pedometer or something like that cant perfectly recall the exact name, and we also did movement of water up the xylem.
Sweet is that the real EMPA or just doing the PSAs for the EMPAs.....We did one of the PSAs, Transpiration pull using a pedometer or something like that cant perfectly recall the exact name, and we also did movement of water up the xylem.
Just the PSA. I have the ISA a month after the PSA. I'm a little worried - have done some reading and the PSA is on respiration and enzymes - which is BIOL1. Due to some work conflicts i'm doing BIOL2 and BIOL4 this year (and BIOL3 obviously), and BIOL1 AND BIOL5 next year...
my college seems to have set my practical BIOL3 on BIOL1.... do i need to know the subject really indepth for the PSA? it obviously only gives me 3 days to learn enzymes and respiration - compared to the months i've spent on BIOL2!
Oh great, Im finding it a lot easier aswell...& its more interesting that Unit 1 it seems to me. We have nearly finished now we only have 2 chapters left.
How far ahead is your college?
Just finished everything. The last chapter for me was mitosis.
My school gave me a empa pack for the last 5 years of empa questions. so im getting that done. I'm also revision the topics that was listed in this upcoming empa.
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