Go to first unread
Back
to top
AQA A Level Biology Paper 3 18th June 2018 Unofficial Markscheme
Watch
Decent paper! Here's my mark scheme - Rehaan 
Q1 Osteoblast - Feedback
1.1
Positive feedback as more insulin produced
Which stimulates more osteoblasts (so deviates further from norm)
1.2
Acidic so more H+ which alter (polarity of) tertiarty structure
So active as complementary to receptors on membrane of Beta cells.
Q2 Rhiz B Cell Question
2.1
Spearman's Rank as looking for correlation.
2.2
The data shows conclusion as positive correlation.
But range for each point
Small sample/only 15
Unaware of effects overtime.
Unaware if healthy or cancer specifically killed.
2.3
1.8 x 10^8
2.4
Non functional NOCHAT1 so non-functional transcription factor
Mutated CD20/non-functional CD20 on membrane
So less Rhizo(?) binds so less death of B cells (as less destroyed)
Q3
CANT REMEMBER
Q4
Q5 (Was this the polar body one?)
a in both boxes.
33 mitochondria
Why is this treatement effective (removing nucleus and putting mitochondria disease cell body into egg).
Prevents inheritance as no nucleus
So when fertilised by sperm zygote will not have disease as no nucleus from mother's egg/may not even form successful zygote for that egg.
Q6 Ammonia
6.1
Microgram - small concentration of ammonia as bacteria
Per gram - allows for comparisons as per gram (so different initial masses accounted for)
6.2
4/5. something?
Graph shows more mRNA yet may not be equal to growth of bacteria. Why?
Not all mRNA translated
So not all secreted into soil as not all produced
So may not take up nitrates from soil
Nitrates used for growth. So cannot say that mRNA = growth.
Q7 Haemocytometer
5.8 something
Why bottom red blood cells counted?
Standardised readings
Bottom of one forms another square so accounted for.
ESSAY:
The importance of the control of movement in cells and organisms.
Calcium ions controlling muscle movement
Spindle fibres controlling chromosome movement
Carrier protein specificity controlling movement across membranes
Insulin controlling movement of glucose into cells
Muscle tissue in arteries controlling movement of blood in vessels
Control of movement of sodium and potassium ions in nerves by voltage gated channels
Enzymes in controlling cell cycle (off spec)
Regulation of gene expression and epigenetics
Control by tumour suppressor genes and protooncogene in tumour formation
IAA in controlling tropisms
Receptors and controlling heart rate as faster movement of blood etc
The importance of interactions
Q1 Osteoblast - Feedback
1.1
Positive feedback as more insulin produced
Which stimulates more osteoblasts (so deviates further from norm)
1.2
Acidic so more H+ which alter (polarity of) tertiarty structure
So active as complementary to receptors on membrane of Beta cells.
Q2 Rhiz B Cell Question
2.1
Spearman's Rank as looking for correlation.
2.2
The data shows conclusion as positive correlation.
But range for each point
Small sample/only 15
Unaware of effects overtime.
Unaware if healthy or cancer specifically killed.
2.3
1.8 x 10^8
2.4
Non functional NOCHAT1 so non-functional transcription factor
Mutated CD20/non-functional CD20 on membrane
So less Rhizo(?) binds so less death of B cells (as less destroyed)
Q3
CANT REMEMBER
Q4
Q5 (Was this the polar body one?)
a in both boxes.
33 mitochondria
Why is this treatement effective (removing nucleus and putting mitochondria disease cell body into egg).
Prevents inheritance as no nucleus
So when fertilised by sperm zygote will not have disease as no nucleus from mother's egg/may not even form successful zygote for that egg.
Q6 Ammonia
6.1
Microgram - small concentration of ammonia as bacteria
Per gram - allows for comparisons as per gram (so different initial masses accounted for)
6.2
4/5. something?
Graph shows more mRNA yet may not be equal to growth of bacteria. Why?
Not all mRNA translated
So not all secreted into soil as not all produced
So may not take up nitrates from soil
Nitrates used for growth. So cannot say that mRNA = growth.
Q7 Haemocytometer
5.8 something
Why bottom red blood cells counted?
Standardised readings
Bottom of one forms another square so accounted for.
ESSAY:
The importance of the control of movement in cells and organisms.
Calcium ions controlling muscle movement
Spindle fibres controlling chromosome movement
Carrier protein specificity controlling movement across membranes
Insulin controlling movement of glucose into cells
Muscle tissue in arteries controlling movement of blood in vessels
Control of movement of sodium and potassium ions in nerves by voltage gated channels
Enzymes in controlling cell cycle (off spec)
Regulation of gene expression and epigenetics
Control by tumour suppressor genes and protooncogene in tumour formation
IAA in controlling tropisms
Receptors and controlling heart rate as faster movement of blood etc
The importance of interactions
6
reply
Report
#3
(Original post by GCSEStudent903)
Osteoblast - Feedback
1.1
Positive feedback as more insulin produced
Which stimulates more osteoblasts (so deviates further from norm)
1.2
pH alters
Osteoblast - Feedback
1.1
Positive feedback as more insulin produced
Which stimulates more osteoblasts (so deviates further from norm)
1.2
pH alters
0
reply
Report
#4
I didn't get to finish my essay 😭 Thanks to stupid application questions taking my time
5
reply
Report
#5
Is this enough for interaction in cells
*DIABETS (ALPHA CELLSS) (I INCLUDED THE IDEA OF PREGNANT WOMEN HAVING GLUCOSE IN URINE AND TEST FOR DIABETES)
* EPITELIAL CELLS (ABSORPTION AND I MENTIONED KIDNEYS)
* COURTSHIP BEHAVIOUR
* TAXONOMY
* XYLEM
*PHLOEM
* TCELLS AND BCELLS ( I MENTIONED ABOUT SCID)
i ran out of time 😭😭😭
*DIABETS (ALPHA CELLSS) (I INCLUDED THE IDEA OF PREGNANT WOMEN HAVING GLUCOSE IN URINE AND TEST FOR DIABETES)
* EPITELIAL CELLS (ABSORPTION AND I MENTIONED KIDNEYS)
* COURTSHIP BEHAVIOUR
* TAXONOMY
* XYLEM
*PHLOEM
* TCELLS AND BCELLS ( I MENTIONED ABOUT SCID)
i ran out of time 😭😭😭
1
reply
Report
#7
(Original post by pploveash)
Is this enough for interaction in cells
*DIABETS (ALPHA CELLSS) (I INCLUDED THE IDEA OF PREGNANT WOMEN HAVING GLUCOSE IN URINE AND TEST FOR DIABETES)
* EPITELIAL CELLS (ABSORPTION AND I MENTIONED KIDNEYS)
* COURTSHIP BEHAVIOUR
* TAXONOMY
* XYLEM
*PHLOEM
* TCELLS AND BCELLS ( I MENTIONED ABOUT SCID)
i ran out of time 😭😭😭
Is this enough for interaction in cells
*DIABETS (ALPHA CELLSS) (I INCLUDED THE IDEA OF PREGNANT WOMEN HAVING GLUCOSE IN URINE AND TEST FOR DIABETES)
* EPITELIAL CELLS (ABSORPTION AND I MENTIONED KIDNEYS)
* COURTSHIP BEHAVIOUR
* TAXONOMY
* XYLEM
*PHLOEM
* TCELLS AND BCELLS ( I MENTIONED ABOUT SCID)
i ran out of time 😭😭😭
0
reply
Report
#8
(Original post by pploveash)
Is this enough for interaction in cells
*DIABETS (ALPHA CELLSS) (I INCLUDED THE IDEA OF PREGNANT WOMEN HAVING GLUCOSE IN URINE AND TEST FOR DIABETES)
* EPITELIAL CELLS (ABSORPTION AND I MENTIONED KIDNEYS)
* COURTSHIP BEHAVIOUR
* TAXONOMY
* XYLEM
*PHLOEM
* TCELLS AND BCELLS ( I MENTIONED ABOUT SCID)
i ran out of time 😭😭😭
Is this enough for interaction in cells
*DIABETS (ALPHA CELLSS) (I INCLUDED THE IDEA OF PREGNANT WOMEN HAVING GLUCOSE IN URINE AND TEST FOR DIABETES)
* EPITELIAL CELLS (ABSORPTION AND I MENTIONED KIDNEYS)
* COURTSHIP BEHAVIOUR
* TAXONOMY
* XYLEM
*PHLOEM
* TCELLS AND BCELLS ( I MENTIONED ABOUT SCID)
i ran out of time 😭😭😭
3
reply
Report
#9
(Original post by pploveash)
Is this enough for interaction in cells
*DIABETS (ALPHA CELLSS) (I INCLUDED THE IDEA OF PREGNANT WOMEN HAVING GLUCOSE IN URINE AND TEST FOR DIABETES)
* EPITELIAL CELLS (ABSORPTION AND I MENTIONED KIDNEYS)
* COURTSHIP BEHAVIOUR
* TAXONOMY
* XYLEM
*PHLOEM
* TCELLS AND BCELLS ( I MENTIONED ABOUT SCID)
i ran out of time 😭😭😭
Is this enough for interaction in cells
*DIABETS (ALPHA CELLSS) (I INCLUDED THE IDEA OF PREGNANT WOMEN HAVING GLUCOSE IN URINE AND TEST FOR DIABETES)
* EPITELIAL CELLS (ABSORPTION AND I MENTIONED KIDNEYS)
* COURTSHIP BEHAVIOUR
* TAXONOMY
* XYLEM
*PHLOEM
* TCELLS AND BCELLS ( I MENTIONED ABOUT SCID)
i ran out of time 😭😭😭
0
reply
Report
#13
I did the movement essay, linked movement of oxygen to cells with aerobic respiration to produce ATP for loads of other processes (muscle contraction, glucose co-transport etc). Anyone else take that approach/ a similar one?
I thought the paper was OK overall
I thought the paper was OK overall
7
reply
Report
#14
Oh my gosh I think I messed the hell up - for the control one the first one I talked about :
-siRNA binding to mRNA and controlling it by not allowing it to do translation
-Control of the movement of phagocytosis on pathogens
-Movement of H+ in respiration
-movement of Calcium in presyanpic neurone
—and something else that I’ll add if I can remember
Someone please help
-siRNA binding to mRNA and controlling it by not allowing it to do translation
-Control of the movement of phagocytosis on pathogens
-Movement of H+ in respiration
-movement of Calcium in presyanpic neurone
—and something else that I’ll add if I can remember
Someone please help
0
reply
Report
#15
(Original post by ppjk)
I got 33 for number of mitochondria in calculation
I got 33 for number of mitochondria in calculation
28
reply
Report
#16
(Original post by ppjk)
Why use micrometers and g-1?
Why use micrometers and g-1?
4
reply
Report
#17
(Original post by vinufailchem3)
What were the two essay titles?
What were the two essay titles?
0
reply
Report
#18
What did you guys get for the question about the haemoglobin and why the right and bottom are not counted???
0
reply
Report
#20
control of movement:
calcium ions controlling muscle movement
spindle fibres controlling chromosome movement
carrier protein specificity controlling movement across membranes
insulin controlling movement of glucose into cells
muscle tissue in arteries controlling movement of blood in vessels
control of movement of sodium and potassium ions in nerves by voltage gated channels
do these sound okay?
calcium ions controlling muscle movement
spindle fibres controlling chromosome movement
carrier protein specificity controlling movement across membranes
insulin controlling movement of glucose into cells
muscle tissue in arteries controlling movement of blood in vessels
control of movement of sodium and potassium ions in nerves by voltage gated channels
do these sound okay?
3
reply
X
Quick Reply
Today on TSR
-
How will Covid-19 affect my uni experience?Video Q&A - the experts answered your questions
- Should I date my friends ex?
- Is it better to live at home or in halls?
- Will I get anywhere with Psychology?
- Is your school opening?