As edexcel biology unit 1 25 may 2017 unofficial mark scheme

Hi guys, hope we all smashed that exam, it was kind of good. Here are my answers that I managed to jot down. Please add your own too
1) a) i) Age ii) General increase in heart rate, avg 52 Beats per min iii) Zebrafish is transparent - easy to see heart etc. Abundant/not rare
iv)verterbrate unlike daphnia so feels pain
b) i) A ii) D
2) a) i) B ii) Diffusion through cell membrane only because single celled & low SA:VOL ratio
b) Alveoli - increase surface area etc
c) 1.05%
d) steepen concentration gradient to make up for high SA:VOL ratio caused by enlarged sacs
3) a) dipolar (explain) glucose attracted, cohesion etc
b) polar, requires channel/carrier protein therefore is facilitated diffusion
c) osmotic effect of glucose. Glycogen insoluble and not polar. Glucose is soluble and polar.
d) i) a-Glucose, 1-4 Glycosidic bonds
ii) Angles of 1-4 glycosidic bonds between a-glucose makes it coil up ->compact. Also insoluble so isnt hydrolysed and glucose not used up until necessary.
4) a) A
b) forgot my answer :/
c) repeat and get average
5) a) D
b) i) wtf was that diagram ii) A
c) i) 27.7% ii) C iii) stored as tryglyceride
d) Explain what CF is and how it happens (chloride ions not being released into mucus etc), mucus builds up in tube between pancreas and small intestine, less digestion, malnourishment, requires higher energy intake.
6) a) collagen - strength to withstand ; elastic fibres - contract to maintain high blood pressure
b) i) atherosclerosis explanation ii) increases blood pressure, risk of another damage and inflammatory response iii) B - antihypertensive
7) a) described structure of mononucleotide, phosphodiester bonds through condensation reactions between phoshate of one and pentose of another. hydrogen bonds, complementary base pairing.
b) just explain mesehlson-stahl findings and how its semi-conservative
c) both have pentose sugar but in DNA its DEOXYRIBOSE and in ATP its RIBOSE. both have phosphate but ATP had triphosphate. Both have nitrogenous base.
8) a) catalyses reactions in organisms by reducing activation energy.
b) i) say collagen is fibrous and enzyme is globular. both consist of polypeptide chains made of amino acids linked with peptide bonds. fibrous have little/no tertiary structure, globular does. explain solubility and insolubility and fibrous has a structural role while glob has functional
ii) 5 different solutions, same volume different concentration. place 5 pieces of same mass collagen and leave for set time. use colorimeter. more colour = less activity.
c) not really valid bc could just be due to enzyme being used up, didnt use control with 0% concentration to compare.

Hope we all smashed it. Please correct any mistakes ^

What do you think the grade boundaries are this year?

Hi guys, hope we all smashed that exam, it was kind of good. Here are my answers that I managed to jot down. Please add your own too
1) a) i) Age ii) General increase in heart rate, avg 52 Beats per min iii) Zebrafish is transparent - easy to see heart etc. Abundant/not rare
iv)verterbrate unlike daphnia so feels pain
b) i) A ii) D
2) a) i) B ii) Diffusion through cell membrane only because single celled & low SA:VOL ratio
b) Alveoli - increase surface area etc
c) 1.05%
d) steepen concentration gradient to make up for high SA:VOL ratio caused by enlarged sacs
3) a) dipolar (explain) glucose attracted, cohesion etc
b) polar, requires channel/carrier protein therefore is facilitated diffusion
c) osmotic effect of glucose. Glycogen insoluble and not polar. Glucose is soluble and polar.
d) i) a-Glucose, 1-4 Glycosidic bonds
ii) Angles of 1-4 glycosidic bonds between a-glucose makes it coil up ->compact. Also insoluble so isnt hydrolysed and glucose not used up until necessary.
4) a) A
b) forgot my answer :/
c) repeat and get average
5) a) D
b) i) wtf was that diagram ii) A
c) i) 27.7% ii) C iii) stored as tryglyceride
d) Explain what CF is and how it happens (chloride ions not being released into mucus etc), mucus builds up in tube between pancreas and small intestine, less digestion, malnourishment, requires higher energy intake.
6) a) collagen - strength to withstand ; elastic fibres - contract to maintain high blood pressure
b) i) atherosclerosis explanation ii) increases blood pressure, risk of another damage and inflammatory response iii) B - antihypertensive
7) a) described structure of mononucleotide, phosphodiester bonds through condensation reactions between phoshate of one and pentose of another. hydrogen bonds, complementary base pairing.
b) just explain mesehlson-stahl findings and how its semi-conservative
c) both have pentose sugar but in DNA its DEOXYRIBOSE and in ATP its RIBOSE. both have phosphate but ATP had triphosphate. Both have nitrogenous base.
8) a) catalyses reactions in organisms by reducing activation energy.
b) i) say collagen is fibrous and enzyme is globular. both consist of polypeptide chains made of amino acids linked with peptide bonds. fibrous have little/no tertiary structure, globular does. explain solubility and insolubility and fibrous has a structural role while glob has functional
ii) 5 different solutions, same volume different concentration. place 5 pieces of same mass collagen and leave for set time. use colorimeter. more colour = less activity.
c) not really valid bc could just be due to enzyme being used up, didnt use control with 0% concentration to compare.

Hope we all smashed it. Please correct any mistakes ^

1 B ii. A
2 B ii. Surely if its a single celled organism it has a large SA:V ratio
3 D ii. Glucose is soluble

the glycogen is insoluble not the glucose, the q was on glycogen and what was question 1bii again? thanks

It was about the blood pressure and we had to pick one of the arrows I believe

Is this new or old spec?

New

1 B ii. A
2 B ii. Surely if its a single celled organism it has a large SA:V ratio
3 D ii. Glycogen is easily hydrolysed because it has branches.

Are you guys the ones who got a 6 marker on what affects a microscopes resolution?

For 2 b ii. I said shorter diffusion thickness given that its 1 cell thick so diffusion from surroundings is adequate to supply cell organs, would this be correct?

nope

is this edexcel biology b or a

Hi guys, hope we all smashed that exam, it was kind of good. Here are my answers that I managed to jot down. Please add your own too
1) a) i) Age ii) General increase in heart rate, avg 52 Beats per min iii) Zebrafish is transparent - easy to see heart etc. Abundant/not rare
iv)verterbrate unlike daphnia so feels pain
b) i) A ii) D
2) a) i) B ii) Diffusion through cell membrane only because single celled & low SA:VOL ratio
b) Alveoli - increase surface area etc
c) 1.05%
d) steepen concentration gradient to make up for high SA:VOL ratio caused by enlarged sacs
3) a) dipolar (explain) glucose attracted, cohesion etc
b) polar, requires channel/carrier protein therefore is facilitated diffusion
c) osmotic effect of glucose. Glycogen insoluble and not polar. Glucose is soluble and polar.
d) i) a-Glucose, 1-4 Glycosidic bonds
ii) Angles of 1-4 glycosidic bonds between a-glucose makes it coil up ->compact. Also insoluble so isnt hydrolysed and glucose not used up until necessary.
4) a) A
b) forgot my answer :/
c) repeat and get average
5) a) D
b) i) wtf was that diagram ii) A
c) i) 27.7% ii) C iii) stored as tryglyceride
d) Explain what CF is and how it happens (chloride ions not being released into mucus etc), mucus builds up in tube between pancreas and small intestine, less digestion, malnourishment, requires higher energy intake.
6) a) collagen - strength to withstand ; elastic fibres - contract to maintain high blood pressure
b) i) atherosclerosis explanation ii) increases blood pressure, risk of another damage and inflammatory response iii) B - antihypertensive
7) a) described structure of mononucleotide, phosphodiester bonds through condensation reactions between phoshate of one and pentose of another. hydrogen bonds, complementary base pairing.
b) just explain mesehlson-stahl findings and how its semi-conservative
c) both have pentose sugar but in DNA its DEOXYRIBOSE and in ATP its RIBOSE. both have phosphate but ATP had triphosphate. Both have nitrogenous base.
8) a) catalyses reactions in organisms by reducing activation energy.
b) i) say collagen is fibrous and enzyme is globular. both consist of polypeptide chains made of amino acids linked with peptide bonds. fibrous have little/no tertiary structure, globular does. explain solubility and insolubility and fibrous has a structural role while glob has functional
ii) 5 different solutions, same volume different concentration. place 5 pieces of same mass collagen and leave for set time. use colorimeter. more colour = less activity.
c) not really valid bc could just be due to enzyme being used up, didnt use control with 0% concentration to compare.

Hope we all smashed it. Please correct any mistakes ^

probably, it makes sense

Okay phew😂 Also, for 8c, the enzyme isn't used up, it's the substrate going from reactants to products!

wow i think I did okay then
lol for that question for UK death rate per 10000 i got 1 in 95 im not sure because people were putting percentages i did 10000/105