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AQA AS Biology paper 1 2018 unofficial markscheme

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how did u find today's paper! :)





This is the official page for the mark scheme for the bio paper done today for AQA if anyone knows any answers please share them on here I will input what I got! :smile:)

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Reply 1
1) D E G?
Coronary arteries
* I can't remeber the order of questions *
Cell surface memebrane
Slime capsule
Cell wall
Flagella

Phospholipids
Melanin

Glycogen
Fatty acid

Add ethanol for the lipid to dissolve and shake then transfer to a testube of water and an emulsion should form that is milky and inseparable when shaken
for Alevoli one:
-across alveoli epithelium
-across alveoli Elastin cell wall
-across capillary endothelium
-simple diffusion as oxygen is non polar

for Water buffer:
-high specific heat capacity
-due to high latent heat of evaporation
-lots of energy needed to break h bonds
-so little energy to change temp of water

for first Cohn Disease one:
-phagocytes attracted to forgein antigen on the surface of bacteria
-macrophage presents on surface
-t cells complementary receptor site binds to antigen so stimulated
-t cell activity increases
-more Crykoemin (that weird toxin thing) released
-so more swelling of artery

Crohn disease why only work for some?
-different strain of bacteria
-immunologically distinct
-antigenic variation changes surface antigen
what did she have to control? (2)
-same starting mass of muscle
-muscle form same organism

what did results show and why?
-conc increases, length decreases
-more atp means more phosphate groups and more high energy bonds broken so more hydrolysis

maths tick box
-i got 440 (B)

Last Crohn Disease one about Enzyme:
-not enough bases for complementy base pairing
-so no replication of T cells
-cannot survive for long
-so less Cryokemina (the weird thing) produced

Alveoli gas exchange:
-Thin alevoli epithelieum
-short diffusion pathway

mrna and trna:
-mrna is simple single strand, trna is clover
-mrna has no paired bases, trna does due to h bonds
-mrna has no amino binding site, trna does
Original post by flosiphy
what did she have to control? (2)
-same starting mass of muscle
-muscle form same organism

what did results show and why?
-conc increases, length decreases
-more atp means more phosphate groups and more high energy bonds broken so more hydrolysis

maths tick box
-i got 440 (B)

Last Crohn Disease one about Enzyme:
-not enough bases for complementy base pairing
-so no replication of T cells
-cannot survive for long
-so less Cryokemina (the weird thing) produced

Alveoli gas exchange:
-Thin alevoli epithelieum
-short diffusion pathway

mrna and trna:
-mrna is simple single strand, trna is clover
-mrna has no paired bases, trna does due to h bonds
-mrna has no amino binding site, trna does


it was 550

latency of evaporation was not needed

if i said coronary blood vessels would that cout?
Lactaolase compared to Lactose
-Similar: both have glycosidic bonds
-Difference: lactaolase has not got glucose, a hexose sugar

the Poo one:
-Lactolase has higher water potential
-Water moves out through osmosis
- Poo and water mix so less hard

The weird Fly one:
-Closely related: Sine song is similar
-Different: the other song had different peaks and different number of peaks
Original post by RickHendricks
it was 550

latency of evaporation was not needed

if i said coronary blood vessels would that cout?


for which question sorry?
I got 660 for the tick box one because it said x base pairs and then nucleotides per second so you had to times it by two
The Smoking one:
-something about SD overlap in open windows
but not in closed (maybe other way round i forgot)
-basically just pros and cons
7.3 Translation Question: (5) - tRNA carries the amino acids to the ribosomes (attachment of amino acids requires ATP) - mRNA attaches to the ribosome - tRNA anticodon attracted to complementary codon on mRNA strand - Two tRNA with two amino acids in ribosome - Peptide bond forms between the two amino acids (condensation, release of water molecule) - Stops translation at stop codon on mRNA - Polypeptide formed
What would ATP hydrolyse into(2)
-ADP
-Pi (inorganic phosphate)
Reply 11
What did u guys get for the energy question released from one dm3 from 1 moldm3
And the percentage question : I got either 84.4 or 87.1
Reply 12
Weird fly question: the two females couldn't mate as they produced the same mating song and therefore would recognise they were female and would not attempt mating
Translation (5)
-mrna leaves through nuclear pore and attaches to ribosome
-ATP used to create bond between trna and amino acid
-trna brings amino acids to ribosome
-trna anticodon bind to complementary mrna codon (first being start codon)
-peptide bonds between amino acids
-trna detached and collects another amino
-polypeptide chain is pulled until stop codon
monomer:
a single simple molecule used to join through condensation to make polymer

proteome:
the complete set of proteins that can be expressed from complete set of genes (genome)
Draw DNA nucleotide:
-phosphate group (circle)
-deoxyribose sugar (pentose)
-nitrogen containing organic base (square) - Adenine Thymine Guanine Cystine
The energy release one:1dm^3= 30500
You convert for cm^3 so multiply by 1,000 Then you divide by 20 to get it for a 0.05cm^3 volume Then you find 40% of that as that is how much is used for contractions= 61,000
Reply 17
i got 1.22x10-4 or something like that because you had to convert it to dm3 and work out the conc. of the atp solution in slide D
Maaaan, I don’t remember what I wrote so I have no idea if what I did was ok
The question about hierachy:
I put it is a hierachy as there are groups within groups and there is no overlap.
The taxon was Family

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