Turn on thread page Beta
    Offline

    10
    ReputationRep:
    Both exams were quite simple tbf, same standard as previous years imo. Therefore it seems most likely that the grade boundaries will replicate those of last year, i.e. 47/48 for C2 and 45-47 for C3.
    Offline

    3
    ReputationRep:
    (Original post by fabsafxo)
    can you do one for biology B2 please??
    Cardiac output.

    148x38=5624 volume ml/blood min, units were given dw.

    Explain why person two had a lower cardiac output? (2 mark)

    Because his stroke volume was much lower, which meant a lower cardiac output.

    Explain why person one ran faster than person two? (5 marks)

    Because person one had a greater cardiac output this meant more blood flow to the muscles from the heart. Therefore a constant supply of glucose and oxygen reached the muscles allowing aerobic respiration to release energy compared to anaerobic which releases less energy and lactic acid. More energy released for running.


    Fossils

    Explain he formation of the fossil archaeopteryx? (2 marks)

    The animal must first die, and the hard parts of the animal were not able to decay leaving a fossil.

    Give two reasons why there were gaps in the record? (2 marks)

    i) More fossils are yet to still be discovered.
    ii)Fossil couldn't be formed because of decay.

    Explain how species could be formed from the ancestor archaeopteryx? ( 4 marks)

    You must first explain natural selection, and then speciation. So something like for e.g Variations in gene caused certain characteristics to be better suited for the environment these animals survived (natural selection) and passed their genes to the future generations. These animals would become so different that interbreeding successfully would not be viable so a specie has been formed. Isolation must be said at the start of this question though.


    Alleles & genetics.

    Describe where the dna is found in human cells? (2 marks)

    Dna found in the nuclear cells as nuclear Dna.

    Minimum allele that needs to be present for polydactyly to be expressed?(1 mark)

    Well considering it is a dominant condition, only one needs to be present.

    Minimum allele that needs to be present for cystic fibrosis to be expressed? (1 mark)

    It's recessive, so two.

    Mendel's experiment.

    The ratio I personally think it's 3:1 as the experiment is directly from his work which consisted of the same ratio esp from the genetic diagram. Also 729/228 = 3.1 makes sense for the ratio to be 3:1. (1 mark)

    Give two reasons why his work wasn't accepted or on those lines which is what they were essentially asking for. (2 marks)

    i) Because he wasn't a renowned scientist, a monk his work wasn't accepted.
    ii) At the time inheritance factors weren't known and hence they didn't really appreciate how important Mendeleev work.

    For the tick boxes, if you do the genetic diagram it was most definitely.(3 marks)

    -Homo
    -Homo
    -Hetero

    Cell structure

    Mitochondria - Sight at which respiration occurs. (1 mark)

    Ribosome - Where protein synthesis occurs. (1 mark)

    Muscle cell magnification is 400. idk how many marks.

    Explain why muscle cells cover the stomach? (2 marks)

    Help to churn the food which would mix with the digestive enzymes.

    Some answers could be wrong tbf, but here you go.
    Offline

    12
    ReputationRep:
    PLease please please can someone post an unofficial mark scheme for C3 and/or the C3 paper if possible?
    Offline

    2
    ReputationRep:
    How did u get 5624 as his cardiac output? i got 3232 or something
    Offline

    3
    ReputationRep:
    (Original post by varun1212)
    How did u get 5624 as his cardiac output? i got 3232 or something
    I'm pretty certain 5624 is correct.
    Offline

    2
    ReputationRep:
    Can somebody post the possible points for the six marker?
    Offline

    2
    ReputationRep:
    (Original post by Decklan)
    I'm pretty certain 5624 is correct.
    Do u know anyone who has the paper for the B2?
    Offline

    3
    ReputationRep:
    (Original post by laura555)
    Can somebody post the possible points for the six marker?
    If it's the sodium thiosulphate concentration question that you're regarding to then:

    -As concentration increased so did gas produced to a certain extent? if that's the other variable can't remember now.

    -This is because there's more particles of Sodium thosulphate for zinc to react with so more gas produced.

    -At 0.7 concentration and afterwards there was no increase in gas production, i.e the reaction has stopped.

    -This is because all the zinc would be reacted (reactant) with the acid and increasing the concentration just meant the additional sodium thiosulphate particles have nothing to react with.
    Offline

    2
    ReputationRep:
    (Original post by Decklan)
    If it's the sodium thiosulphate concentration question that you're regarding to then:

    -As concentration increased so did gas produced to a certain extent? if that's the other variable can't remember now.

    -This is because there's more particles of Sodium thosulphate for zinc to react with so more gas produced.

    -At 0.7 concentration and afterwards there was no increase in gas production, i.e the reaction has stopped.

    -This is because all the zinc would be reacted (reactant) with the acid and increasing the concentration just meant the additional sodium thiosulphate particles have nothing to react with.

    Thanks this is really helpful!
    Offline

    16
    ReputationRep:
    I think I lost 9 marks according to this so should be an A* (51/60)

    is there a C3 unofficial mark scheme?
    Offline

    0
    ReputationRep:
    on the empirical formula i got pbo6 isn't that the same as pb2o3 - thanks for the mark scheme too dude
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by AbdallaAyanle)
    on the empirical formula i got pbo6 isn't that the same as pb2o3 - thanks for the mark scheme too dude
    Unfortunately no, but if you can remember what you did for your working out, I can tell you how many marks you probably will have gotten from workings out?

    And my grade boundaries prediction will be:
    Unit 2:
    A* - 49/60
    A - 42/60
    B - 35/60
    C - 28/60
    D - 22/60

    Unit 3:
    A* - 46/60
    A - 37/60
    B - 28/60
    C - 21/60
    Offline

    1
    ReputationRep:
    5(d) for the pb2O3 isn't it pbO6 because u can't put a 2 infront on of the O unless u make it 2BPO3? (i'm not sure) but i wrote pbO6 if im wrong what's the maximum marks i can lose? i put in to a ratio between the 6.21 and the 0.72 and then i made it both whole numbers and divided it by the mass which was 207 and 16 for both of them.
    Offline

    14
    ReputationRep:
    I predict 47 for A* 40 for A in both papers. I found them hard but people generally found it quite easy and they were actually quite simple looking back. Does anyone have the C3 unofficial Markscheme or can make one?
    Offline

    1
    ReputationRep:
    (Original post by NeverGrowUp)
    I predict 47 for A* 40 for A in both papers. I found them hard but people generally found it quite easy and they were actually quite simple looking back. Does anyone have the C3 unofficial Markscheme or can make one?
    most people in twitter found c3 hard and my school found it hard even though i found it decent, it won't be 47+ for c3 definitely not, i think maybe 45, lol 2013 b3 paper biology 36 for an a* and that was paper was so easy hence why i think this (as it's based on how the whole country does).
    Offline

    2
    ReputationRep:
    (Original post by neil20143)
    Hi I tried to make an unofficial mark scheme for this. Please be free to add things

    1a. State one conclusion about the effect of temperature on the rate of reaction? (1 mark)
    -An increase in temperature increases the rate of reaction

    aii. One reason why? (1 mark)
    -Because the volume of gas being produced at 40 degrees was more rapid than at 20 degrees.

    a(iii). Average rate (1 mark)
    -2 cm cubed per second (I think)

    1 (b) two students should the student keep constant? (2 marks)
    -Mass of Marble Chips
    -Concentration of acid

    b ii. Increasing the surface area affect the rate of reaction? (2 marks)

    -Increases the rate of reaction
    -As the particles are colliding more frequently (more successful collisions)

    c. Why does a catalyst reduce costs?
    -Because less energy is needed to start the reaction (as it has a lower activation energy)

    (there may be alternatives)

    2 (a). What could the student see? (1 mark)
    -Copper being formed (brown) or zinc disappearing

    2(b).Improves the investigation? (2 marks)
    Improvement: Use a lid/ insulate the container
    Reason: Prevents heat from being transferred to the surroundings/escaping.

    2c (6 marker - will do later at some point)

    3 (a). How does a metal conduct electricity? (4 marks)
    -Delocalised electrons can move through the metal
    -Transfer electrical charge
    -Sea of moving electrons (structure)
    -Lattice of positive ions (structure)

    3(b). Describe the structure of an alloy is different to a metal (2 marks)
    -Different elements with different sizes
    -Distort layers in the mixture, preventing them from sliding over each other.
    OR
    -Irregular pattern of atoms.

    3(c). Why is Nitinol used in braces? (1 mark)
    -Hard/strong/corrosive-resistant/smart-alloy

    3(c) (ii). Why are coins not made out of pure copper? (1 mark)
    -Because it is too soft so will corrode

    3 (c) (iii)). Aluminium Oxide

    3 (c) (iv). How can the reaction produce two different products? (1 mark)
    -Made using different reaction conditions / any specified reaction condition (e.g. pressure, temperature).
    -Using different catalysts

    3(d). Instrumental methods are used to detect impurities? (2 marks)
    Any two from:
    -They use very little samples.
    -Accurate
    -Sensitive
    -Fast

    4 (a). Why does Lithium have 7 as it's atomic number? (3 marks)
    -3 protons
    -4 neutrons
    -3 + 4 = 7 which is its mass
    -electrons have a very small mass.

    4(b). Complete the sentences (2 marks)
    -Grams
    -Carbon-12

    4(c). Isotope differences (3 marks)
    -18-Oxygen had 2 more neutrons than 16-Oxygen
    -Same number of protons
    -Same number of electrons

    5 (a). Name a soluble compound that contains silver
    (1 mark)
    -Silver Nitrate

    5(a) ii Compound containing carbonate ions (1 mark)
    -Potassium or Sodium Carbonate

    5(b) (1 mark)
    -(insoluble)Base

    5(c) (i). State how lead nitrate can be obtained from lead nitrate oxide (1 mark)
    -Crystalisation
    -Evaporate and leave to dry.

    5c(ii) (1 mark)

    Pbo + 2HNO3 = PB(NO3) + H2O

    5c (iii). number of atoms in the compound
    -9

    5(d). Empirical Formula (4 marks)
    Pb2O3


    6(a). Structure and bonding in sodium chloride (4 marks)
    -Ionic Bonding
    -Sodium atoms lose one electron to form positive ions
    -Chloride ions gain one electron to form negative ions
    -Opposites attract
    -Giant ionic structure
    -Cubic Lattice
    -Electrostatic forces

    Any of these should get the mark I think

    6(b). Other products when brine is electrolysed (2 marks)
    -Sodium Hydroxide
    -Hydrogen

    6(c). Ethical reason for not putting Iodine in food (1 mark)
    -People may not want to have these extra Iodine amount (no choice)

    6(d) (i). (2 marks)
    -3 electrons lone pairs and one covalent bond

    6(d) (ii). Why does Iodine have a low melting point (3 marks)
    -Simple molecules
    -Weak intermollecular forces
    -Little energy needed to break them down

    6(d) (iii). Why does iodine not conduct electricity? (2 marks)
    -No overall charge so can't carry electrical charge

    (I'm not sure about this question)
    Isn't the answer to 6(d) (iii) Because it has no free electrons able to carry charge due to them being used in the covalent bond?
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by RG110man)
    Isn't the answer to 6(d) (iii) Because it has no free electrons able to carry charge due to them being used in the covalent bond?
    Not sure, I used my AQA book to put in the answer for it.
    Offline

    14
    ReputationRep:
    (Original post by Abdalla__67)
    most people in twitter found c3 hard and my school found it hard even though i found it decent, it won't be 47+ for c3 definitely not, i think maybe 45, lol 2013 b3 paper biology 36 for an a* and that was paper was so easy hence why i think this (as it's based on how the whole country does).
    45 is still high
    Offline

    0
    ReputationRep:
    Could you make a Mark Scheme for C3 by any chance?
    Offline

    0
    ReputationRep:
    (Original post by neil20143)
    Hi I tried to make an unofficial mark scheme for this. Please be free to add things

    1a. State one conclusion about the effect of temperature on the rate of reaction? (1 mark)
    -An increase in temperature increases the rate of reaction

    aii. One reason why? (1 mark)
    -Because the volume of gas being produced at 40 degrees was more rapid than at 20 degrees.

    a(iii). Average rate (1 mark)
    -2 cm cubed per second (I think)

    1 (b) two students should the student keep constant? (2 marks)
    -Mass of Marble Chips
    -Concentration of acid

    b ii. Increasing the surface area affect the rate of reaction? (2 marks)

    -Increases the rate of reaction
    -As the particles are colliding more frequently (more successful collisions)

    c. Why does a catalyst reduce costs?
    -Because less energy is needed to start the reaction (as it has a lower activation energy)

    (there may be alternatives)

    2 (a). What could the student see? (1 mark)
    -Copper being formed (brown) or zinc disappearing

    2(b).Improves the investigation? (2 marks)
    Improvement: Use a lid/ insulate the container
    Reason: Prevents heat from being transferred to the surroundings/escaping.

    2c (6 marker - will do later at some point)

    3 (a). How does a metal conduct electricity? (4 marks)
    -Delocalised electrons can move through the metal
    -Transfer electrical charge
    -Sea of moving electrons (structure)
    -Lattice of positive ions (structure)

    3(b). Describe the structure of an alloy is different to a metal (2 marks)
    -Different elements with different sizes
    -Distort layers in the mixture, preventing them from sliding over each other.
    OR
    -Irregular pattern of atoms.

    3(c). Why is Nitinol used in braces? (1 mark)
    -Hard/strong/corrosive-resistant/smart-alloy

    3(c) (ii). Why are coins not made out of pure copper? (1 mark)
    -Because it is too soft so will corrode

    3 (c) (iii)). Aluminium Oxide

    3 (c) (iv). How can the reaction produce two different products? (1 mark)
    -Made using different reaction conditions / any specified reaction condition (e.g. pressure, temperature).
    -Using different catalysts

    3(d). Instrumental methods are used to detect impurities? (2 marks)
    Any two from:
    -They use very little samples.
    -Accurate
    -Sensitive
    -Fast

    4 (a). Why does Lithium have 7 as it's atomic number? (3 marks)
    -3 protons
    -4 neutrons
    -3 + 4 = 7 which is its mass
    -electrons have a very small mass.

    4(b). Complete the sentences (2 marks)
    -Grams
    -Carbon-12

    4(c). Isotope differences (3 marks)
    -18-Oxygen had 2 more neutrons than 16-Oxygen
    -Same number of protons
    -Same number of electrons

    5 (a). Name a soluble compound that contains silver
    (1 mark)
    -Silver Nitrate

    5(a) ii Compound containing carbonate ions (1 mark)
    -Potassium or Sodium Carbonate

    5(b) (1 mark)
    -(insoluble)Base

    5(c) (i). State how lead nitrate can be obtained from lead nitrate oxide (1 mark)
    -Crystalisation
    -Evaporate and leave to dry.

    5c(ii) (1 mark)

    Pbo + 2HNO3 = PB(NO3) + H2O

    5c (iii). number of atoms in the compound
    -9

    5(d). Empirical Formula (4 marks)
    Pb2O3


    6(a). Structure and bonding in sodium chloride (4 marks)
    -Ionic Bonding
    -Sodium atoms lose one electron to form positive ions
    -Chloride ions gain one electron to form negative ions
    -Opposites attract
    -Giant ionic structure
    -Cubic Lattice
    -Electrostatic forces

    Any of these should get the mark I think

    6(b). Other products when brine is electrolysed (2 marks)
    -Sodium Hydroxide
    -Hydrogen

    6(c). Ethical reason for not putting Iodine in food (1 mark)
    -People may not want to have these extra Iodine amount (no choice)

    6(d) (i). (2 marks)
    -3 electrons lone pairs and one covalent bond

    6(d) (ii). Why does Iodine have a low melting point (3 marks)
    -Simple molecules
    -Weak intermollecular forces
    -Little energy needed to break them down

    6(d) (iii). Why does iodine not conduct electricity? (2 marks)
    -No overall charge so can't carry electrical charge

    (I'm not sure about this question)

    do u have the 6 markers answers yet?
    also so far from the unofficial mark scheme you have produced i have got 41/60 what grade do u think that would be?
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: April 10, 2016

1,271

students online now

800,000+

Exam discussions

Find your exam discussion here

Poll
Should predicted grades be removed from the uni application process

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.