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) [B]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

e) Infertile: (2)

- homologous chromosomes cannot pair

- thus meiosis cannot occur

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

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

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Last edited by AhmedDavid; 5 hours ago at 19:34.

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10-02-2014 12:42

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Re: AQA As Biology June 2014 - [BIO2]

Thank you for starting this thread. This has been really helpful.

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17-02-2014 10:34

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Re: AQA As Biology June 2014 - [BIO2]

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