Q1.
A leaf is a plant organ.
Figure 1 shows tissues in a leaf.
Figure 1

(a)  Which tissue is the epidermis?
Tick (✓) one box.
 
A		B		C		D		
(1)
(b)  Explain how the spongy mesophyll is adapted for its function.
Use Figure 1.
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(3)
(c)  The xylem is adapted to transport water through a plant.
Explain one way that xylem is adapted for its function.
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(2)
(d)  Figure 2 shows a pair of guard cells around a stoma.
Figure 2

During the day, glucose is made in the guard cells.
Describe how an increase in glucose concentration in the guard cells causes the stoma to open.
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(2)
(Total 8 marks)
Q2.
Blood glucose concentration in the human body needs to be kept within the normal range.
The figure below shows that two hormones control blood glucose concentration.
 
(a)  Name the type of hormonal control shown in the figure above.
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(1)
(b)  Name hormones A and B in the figure above.
A  ________________________________________________________________
B  ________________________________________________________________
(1)
(c)  Explain how the two hormones in the figure above keep the blood glucose concentration within the normal range for 3 hours after a meal.
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(6)
Female reproductive hormones are used to treat infertility in women.
(d)  Follicle Stimulating Hormone (FSH) and then Luteinising Hormone (LH) can be injected into a woman to help her become pregnant by sexual intercourse.
Explain how injecting FSH and then LH will help a woman to become pregnant.
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(3)
(e)  In some women the injections of FSH and LH are the first steps for In Vitro Fertilisation (IVF).
Describe the remaining steps in IVF.
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(4)
(f)  There are two different processes of cell division in humans.
Describe three differences between cell division to form sperm cells compared with cell division to form liver cells.
1  _________________________________________________________________
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2  _________________________________________________________________
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3  _________________________________________________________________
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(3)
(Total 18 marks)
Q3.
Cells are the basic units of all forms of life.
(a)     Describe four differences between a bacterial cell and a plant cell.
1. _________________________________________________________________
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2. _________________________________________________________________
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3. _________________________________________________________________
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4. _________________________________________________________________
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(4)
(b)     Gonorrhoea is a bacterial disease.
A new vaccine is being developed against gonorrhoea.
Describe how a vaccine would work to prevent gonorrhoea.
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(4)
Another disease caused by bacteria is salmonella food poisoning.
In the UK, chickens are vaccinated against Salmonella bacteria to reduce the number of cases of food poisoning in humans.
(c)     Explain how vaccinating chickens reduces the number of cases of salmonella food poisoning.
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(2)
(d)     Give one way that the spread of salmonella food poisoning from one human to another is controlled.
Do not refer to vaccination in your answer.
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(1)
(e)     The number of cases of salmonella food poisoning is usually higher in summer than in winter.
Suggest one reason why.
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(1)
(Total 12 marks)
Q4.
Figure 1 shows a root hair viewed using a microscope.
Figure 1
 
(a)  The root hair was viewed at a magnification of ×50
The image length of the root hair X–Y is 43 mm
Calculate the real length of the root hair in micrometres (µm).
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Real length = ___________________________ µm
(4)
(b)  A microscope has a ×5 eyepiece lens.
Describe how to use this microscope to observe a prepared slide of root hair cells at a magnification of ×50
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(4)
Root hair cells absorb water and mineral ions from the soil.
A scientist investigated the rate of nitrate ion uptake by two seedlings.
Figure 2 shows how the investigation was set up.
Figure 2
 
The scientist determined the mass of nitrate ions absorbed by each seedling every 30 minutes for 4 hours.
The table shows the results.
 
Time in hours	Total mass of nitrate ions absorbed by seedling in arbitrary units	
	With oxygen added	With no oxygen added	
0	0	   0	
0.5	100	  60	
1.0	145	  95	
1.5	170	105	
2.0	195	115	
2.5	215	120	
3.0	235	125	
3.5	250	130	
4.0	265	130	
(c)  Describe the changes in the rate of absorption of nitrate ions for the seedling with no oxygen added.
Use information from the table.
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(3)
(d)  Explain what the results in the table above show about how nitrate ions are absorbed.
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(4)
(e)  Nitrate ions are essential for plants to grow.
Describe how nitrate ions are used in a plant to help the plant grow.
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(3)
(Total 18 marks)
Q5.
A student investigated the effect of different concentrations of sugar solution on pieces of carrot.
This is the method used.
1.   Weigh five pieces of carrot.
2.   Place each piece into a different tube.
3.   Into each tube add 20 cm3 of water or one of the sugar solutions as shown in Figure 1
4.   Leave the apparatus for 2 hours.
5.   Remove the carrot and dry each piece on paper towel.
6.   Reweigh each piece.
7.   Calculate the percentage (%) change in mass of each piece.
Figure 1 shows how the investigation was set up.
Figure 1
 
The table below shows the results.
 
Concentration of sugar solution in mol/dm3	Percentage (%) change in mass	
0.0	+24	
0.2	+12	
0.4	+1	
0.6	−8	
0.8	−15	
(a)  Suggest why the student calculated the percentage (%) change in mass of each piece of carrot.
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(1)
(b)  Complete Figure 2 using the results in the table above
•   Choose a suitable scale and label for the y-axis.
•   Plot the results.
•   Draw a line of best fit.
Figure 2
 
(4)
(c)  Estimate the concentration of sugar solution inside the carrot cells.
Use your completed graph on Figure 2
Concentration = _______________________ mol/dm3
(1)
(d)  Explain why the mass of the carrot in the 0.6 mol/dm3 sugar solution changed.
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(4)
(e)  The student repeated the investigation using boiled pieces of carrot.
The pieces of carrot did not change in mass.
Suggest why.
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(1)
(Total 11 marks)
Q6.
Plants have tissues that are specialised for the transport of food and water molecules.
(a)     Which is a description of the role of the xylem?
Tick one box.
 
Transports dissolved sugars using translocation		
Transports starch in the transpiration stream		
Transports water in the transpiration stream		
Transports water using translocation		
(1)
(b)     Which is a description of the role of the pholem?
Tick one box.
 
Transports dissolved sugars in the transpiration stream		
Transports dissolved sugars using translocation		
Transports starch using translocation		
Transports water in the transpiration stream		
(1)
In plants water is lost through stomata.
Figure 1 shows stomata on the lower surface of a leaf.
Figure 1

(c)     Calculate the number of stomata per mm2 for the leaf shown in Figure 1.
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Number of stomata = ____________________ 
(2)
(d)     Most plants have more stomata on the lower surface of a leaf than on the upper surface.
Explain why there are more stomata on the lower surface of a leaf.
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(3)
(e)     Particles can move into and out of cells by different processes.
Figure 2 shows different particles inside and outside a root hair cell.
Figure 2

Explain the processes by which the different particles would enter the root hair cell.
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(6)
(Total 13 marks)
Q7.
This question is about stem cells.
(a)  Give one place in a plant where stem cells are found.
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(1)
(b)  What is one economic use of plant stem cells?
Tick one box.
 
To create genetically modified crops		
To create new species of plants		
To increase variation in plants		
To produce large numbers of identical plants		
(1)
Embryonic stem cells divide by mitosis.
Figure 1 represents a cell cycle for a human embryonic stem cell.
Figure 1
 
(c)  The mass of DNA in the cell at the start of the cycle is 6 picograms.
A picogram is 10−3 nanograms.
Convert 6 picograms to grams.
Give your answer in standard form.
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Mass = _____________________ g
(1)
(d)  The time taken for this complete cell cycle is 15 hours.
Calculate how many hours the cell spent in mitosis.
Give your answer to 3 significant figures.
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Time spent in mitosis = _____________________ hours
(2)
(e)  Describe what happens in each of the three stages of the cell cycle.
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(5)
(f)  Figure 2 shows how embryonic stem cells are produced in therapeutic cloning for use in patients.
Figure 2
 
Give two advantages and two disadvantages of therapeutic cloning in medical treatments.
Use Figure 2 to help you.
Advantage 1 ________________________________________________________
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Advantage 2 ________________________________________________________
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Disadvantage 1 ______________________________________________________
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Disadvantage 2 ______________________________________________________
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(4)
(Total 14 marks)
Q8.
Eukaryotic cells respire continuously to transfer energy.
(a)     Give two uses of energy transferred by respiration in eukaryotes.
1. _________________________________________________________________
2. _________________________________________________________________
(2)
(b)     Name the cell structure in a eukaryotic cell where aerobic respiration occurs.
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(1)
(c)     Muscle cells and plant cells can respire anaerobically.
Compare the processes of anaerobic respiration in muscle and plant cells.
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(4)
(d)     Anaerobic respiration in muscle cells creates an oxygen debt.
What does oxygen debt mean?
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(1)
(Total 8 marks)

Mark schemes
Q1.
(a)  A
1
(b)  has (large) air spaces (between cells)
allow has (large) gaps (between cells)
1
(so) gases can diffuse / move through the leaf
allow carbon dioxide or oxygen or water vapour for gases
1
to / from the photosynthetic / palisade / B layer
allow to / from the upper mesophyll
if named gas given for mp 2 direction of movement must be correct
1
if no other marks awarded allow 1 mark for cells have chloroplasts for photosynthesis
(c)  composed of hollow tubes / cells
allow cells are empty
allow no cytoplasm / nucleus / sub-cellular structures
1
(so) no obstruction to water flow
allow (so) water flows easily if linked to hollow tubes
allow to maintain the transpiration stream
OR
has lignin (1)
ignore has thick walls
(to) hold tubes open (1)
or
(to) strengthen the tubes
allow (to) keep water inside xylem
allow (to) make tubes rigid
OR
no end walls (1)
(so) water flows easily (1)
or
(so) water flows continuously
must be linked to an adaptation
allow (so) maintains a constant water flow
allow to maintain the transpiration stream
1
reason must correctly match the structure
(d)  water enters (guard) cells by osmosis
allow water enters (guard) cells because the concentration of water is higher outside the cell than inside the cell
1
cells swell and curve (to open the stoma)
allow cells become turgid and curve (to open the stoma)
allow inner wall of (guard) cell is thicker / stronger or less flexible than outer wall so cells curve (to open stoma)
1
[8]
Q2.
(a)  negative feedback (control)
ignore homeostasis
1
(b)  A = glucagon
B = insulin
both required in correct order
correct or phonetic spelling only
1
(c)  Indirect marking
view with (b)
(when blood glucose concentration is high after a meal) insulin / B is secreted (by the pancreas) causing glucose to enter cells
1
(glucose is) converted to glycogen in the liver / muscle (cells for storage)
1
(this causes) blood glucose concentration to return to normal so insulin / B secretion slows / stops / decreases
1
when blood glucose concentration is low glucagon / A is secreted (by the pancreas)
1
(which causes) breakdown of glycogen in the liver (into glucose)
allow (which causes) breakdown of glycogen in the muscle (cells)
1
(this causes) blood glucose concentration to return to normal so glucagon / A secretion slows / stops / decreases
1
(d)  FSH causes (several) ova / eggs to mature (in the ovary)
allow singular ovum / egg
allow follicle for ovary
1
(then) LH causes ovulation
or
LH causes release of the ova / eggs
allow singular ovum / egg
1
so more eggs / ova present therefore higher probability / chance of fertilisation
or
so more eggs / ova present therefore higher probability / chance of sperm fusing with an egg
1
(e)  collection of (mature) egg(s) from the ovary
allow follicle for ovary
1
(which are) fertilised (in the laboratory)
do not accept if in fallopian tube
allow egg and sperm fuse
1
develop into embryo(s) (in the laboratory)
allow develop / divide into small balls of cells (in the laboratory)
do not accept foetus
1
embryo(s) inserted into uterus / womb
1
(f)  any three from:
•   meiosis for sperm cells and mitosis for liver cells
•   two cell divisions to form sperm and one cell division to form liver (cells)
•   four genetically different sperm cells and two genetically identical liver cells
allow four genetically different cells formed from meiosis and two genetically identical cells formed from mitosis
•   sperm cells have 23 chromosomes and liver cells have 46 chromosomes
allow sperm cells have 23 chromosomes and liver cells have 23 pairs of chromosomes
allow haploid (sperm) and diploid (liver cells)
ignore reproduction
max 2 marks if reference to sperm cells dividing
3
[18]
Q3.
(a)  any four from:
•   bacterial cell is smaller (than a plant cell)
allow converse statements ‘it’ refers to bacteria
•   bacterial cell does not have chloroplasts (plant cell does)
ignore chlorophyll
•   bacterial cell does not have its DNA / genetic material inside a nucleus (plant cell does)
allow bacterial cell does not have a nucleus (plant cell does)
allow bacterial cell has DNA / genetic material in a ring / loop (plant cell does not)
allow bacterial cell has DNA / genetic material free in cytoplasm
•   bacterial cell (may) have plasmids (plant cell does not)
•   bacterial cell does not have mitochondria (plant cell does)
•   cell wall in bacterial cells is not made of cellulose (cell wall in plant cells is)
•   bacterial cell does not have a large / permanent vacuole (plant cell does)
•   bacterial cell has smaller ribosomes (than plant cells)
do not accept idea that bacterial cells do not have ribosomes
allow bacterial cell (may) have a flagellum (plant cells do not)
allow bacterial cell (may) have a slime capsule (plant cell does not)
4
(b)  any four from:
•   dead / inactive / weakened form of pathogen / bacterium / microorganism is introduced / injected
allow introduce / inject antigen(s) from the pathogen
allow dead / inactive / weakened form of Gonorrhoea (bacteria) introduced / injected
do not accept inject Gonorrhoea disease
•   white blood cells stimulated to produce antibodies
do not accept incorrect white blood cell, eg phagocyte
•   reference to memory cells made or remain
•   on re-exposure specific / correct antibodies are made (very) quickly
allow on re-exposure specific / correct antibodies are produced in large quantities
•   bacteria / pathogens / microorganisms killed and do not produce a large enough population to cause the disease
allow bacteria / pathogens / microorganisms killed and do not produce a large enough population to produce toxins
4
(c)  fewer bacteria / pathogens in chicken / eggs / food
ignore references to immunity unqualified
allow fewer chickens / eggs will carry the bacteria / pathogens ignore chickens do not get disease / infected
1
(so) fewer bacteria are ingested (by humans)
allow idea of fewer bacteria being passed on to humans in food
or
fewer bacteria / pathogens ingested (by humans) (1)
(so) fewer toxins produced (1)
allow idea of fewer bacteria being passed on to humans in food (1)
1
(d)  wash hands before preparing food
ignore wash hands unqualified
allow good food hygiene
wash hands after using the toilet
allow clean areas where a person has been ill
allow do not shake hands (with someone who has food poisoning)
1
(e)  warmer weather so bacteria reproduce / increase faster
ignore bacteria are killed at low temperatures
allow food not cooked properly on barbeques
1
[12]
Q4.
(a)   
1
(size of real object =)  
1
(size of real object =) 0.86 (mm)
1
(size of real object =) 860 (µm)
an answer of 860 (µm) scores 4 marks
allow correct conversion of their calculated value
if no other marks awarded allow 1 mark for
 
1
(b)  Level 2: Scientifically relevant facts, events or processes are identified and given in detail to form an accurate account.
3−4
Level 1: Facts, events or processes are identified and simply stated but their relevance is not clear.
1−2
No relevant content
0
Indicative content
•   place slide on stage
•   use lowest power / ×4 objective lens (initially)
•   adjust mirror or switch light on so light passes through slide
•   move stage as close to lens as possible
•   slide must not touch lens
•   turn focussing knob so slide moves away from lens
•   turn focussing knob until image comes into focus
•   use fine focus to get clear image
•   change objective lens to ×10
•   ×5 eyepiece and ×10 objective lenses (gives total magnification of ×50)
•   refocus slide using focussing knob
For Level 2 reference to how to focus the slide / cells and achieve magnification of ×50 is required
(c)  any three from:
•   (rate) fastest in the first 0.5 hours
allow fastest rate is 120 units per hour (at start)
•   (rate gradually) decreases after first 0.5 hours
allow mean rate over 3.5 hours is 37.14 units per hour
or
•   (rate gradually) decreases throughout the investigation
•   rate is constant between 1.0 and 2.0 hours
or
•   rate is constant between 2.0 and 3.5 hours
•   (rate) becomes zero between 3.0 and 3.5 hours
allow (rate) is zero after 3.5 hours
allow 'it’ for rate
3
(d)  more nitrate ions are absorbed in the presence of oxygen
allow nitrate ions absorbed faster in the presence of oxygen
1
(which suggests) they are absorbed by active transport / uptake
1
which requires energy from respiration
do not accept energy produced / created / made
1
some nitrate ions absorbed by diffusion
or
some nitrate ions absorbed (by active transport / uptake) requiring energy from anaerobic respiration
or
some nitrate ions absorbed by active transport / uptake using oxygen already dissolved in the solution
1
(e)  nitrate ions are used with glucose
1
to form amino acids
1
(which are) used to synthesise proteins (needed for growth)
1
[18]
Q5.
(a)  to control for the starting mass (of the pieces of carrot)
allow because the pieces of carrot were not all the same mass at the start
do not accept were not all the same size
do not accept as a control variable
1
(b)  suitable scale and label for y-axis
allow 5 or 6 per 2 cm
do not accept 5 per 1 cm
1
all points plotted correctly
allow ± ½ a square
allow 1 mark for 4 correct points
2
line of best fit
 
conc. …	percentage
(%) change…	
0.0	+24	
0.2	+12	
0.4	+1	
0.6	−8	
0.8	−15	
1
(c)  value from student’s line of best fit
allow ± ½ a square
1
(d)  mass decreased
1
(due to) loss of water by osmosis
ignore diffusion
1
through a partially / selectively / semi permeable membrane
1
a clear reference to concentration of water or concentration of sugar is required for the fourth mark
(as) concentration of sugar solution is greater than concentration of sugar (solution) inside cells / carrot
allow (as) concentration of sugar solution inside cells / carrot is lower than the concentration of sugar solution (in the tube or around the carrot)
or
(as) the concentration of water is less outside the cells / carrot than the concentration inside the cells / carrot
allow answers in terms of dilute and concentrated solutions
1
(e)  the (partially permeable / cell) membrane was damaged
allow idea that cell membrane is no longer intact
or is more permeable / leaky
allow the membrane is denatured
ignore cells are dead
1
[11]
Q6.
(a)     transports water in the transpiration stream
1
(b)     transports dissolved sugars using translocation
1
(c)     2/(0.1 × 0.1)
or
2/ 0.01
1
200
an answer of 200 scores 2 marks
1
(d)     cooler around lower surface
1
more humid around lower surface
allow converse argument for upper surface of leaf if qualified
1
(so) less water evaporated
allow less breeze around lower surface
1
(e)     
Level 3: Relevant points (correct processes / explanations) are identified, given in detail and linked logically to form a clear account.	5-6	
Level 2: Relevant points (correct processes / explanations) are identified and there are attempts at logical thinking. The resulting account is not fully clear.	3-4	
Level 1: Points are identified and stated simply, but their relevance is not clear and there is no attempt at logical thinking.	1-2	
No relevant content	0	
Indicative content
•   water is absorbed by osmosis
•   osmosis is a passive process, or described
•   water in soil is at a higher concentration than inside cell
•   water moves down concentration gradient
•   through a partially permeable membrane
•   phosphate ions absorbed by diffusion
•   diffusion is a passive process, or described
•   phosphate ions are in a higher concentration in soil than inside cells
•   magnesium ions are absorbed by active transport
•   magnesium ions are in lower concentration in soil than inside cells
•   magnesium ions move from an area of lower concentration to an area of higher concentration inside the cells
•   magnesium ions move up the concentration gradient
•   process requires energy
•   energy from respiration	 	
6
[13]
Q7.
(a)  any one from:
•   meristem(s)
•   tip of shoot
ignore stem and embryo
•   tip of root
1
(b)  to produce large numbers of identical plants
1
(c)  6 × 10−12 (grams)
1
(d)  
or
1.166666666(r)
 
allow correct rounding
allow 1.16
1
1.17 (hours)
allow 1 mark for 1 hour 10 minutes or 1 and 1/6 hours or 70 minutes only if units given
1
an answer of 1.17 (hours) scores 2 marks
(e)  stage 1
cell growth
or
increase in number of organelles
allow increase in named organelle e.g. ribosomes / mitochondria
1
DNA replicates*
or
two copies of each chromosome form*
*allow DNA duplicates / doubles
*ignore genetic information replicates
*if this statement given as part of stage 2 allow max 4 marks
1
stage 2 / mitosis
one set of chromosomes moves to each end of cell
allow chromosomes separate or are pulled apart
1
nucleus divides
allow nucleus splits into two
1
stage 3
cytoplasm / cell membrane divides to form two (genetically) identical cells
allow cytokinesis
1
max 4 if correct sequence but no reference to stage numbers
max 4 marks if no stage numbers given
ignore names of phases
marks can be awarded for labelled diagrams
(f)  any two from:
advantages:
•   may be used to cure / treat (current / future) diseases
    or
    cure medical conditions
    or
    produce replacement cells / tissues / organs
allow example e.g. diabetes / paralysis
ignore used for medical treatments
•   cells / tissues of any type could be produced
allow cells differentiate into many types
•   cells / tissues of any type could be produced
ignore identical cells are produced unqualified
•   many cells produced
•   cells produced could be used for research
•   would reduce waiting time for organ transplants
2
any two from:
ignore references to cost
ignore unethical unqualified
ignore references to religion / beliefs
disadvantages:
•   potential life is killed / destroyed
allow embryo is destroyed
ignore cells destroyed or wasted
•   shortage of donors / eggs
•   egg donation / collection has risks
•   do not yet know risks /side effects of the procedure on the patient
allow may cause tumours / cancer
•   may transfer (viral) infection
•   poor success rate to produce viable eggs / embryo
2
ignore references to cost
[14]
Q8.
(a)     any two from:
•        synthesis of new molecules
allow named molecule eg starch / glycogen / cellulose / lipids / fats / proteins / hormones / antibodies
•        for active transport
•        to keep warm (in mammals / birds)
allow description
allow to keep warm (in animals)
allow for movement (in animals)
allow for transmission of nerve impulses (in animals)
2
(b)     mitochondria / mitochondrion
1
(c)     both occur without oxygen
1
both release (a small amount of) energy
1
muscle cells produce lactic acid but plant cells produce ethanol
1
muscle cells do not produce carbon dioxide but plant cells do
marks can be awarded from correct word or balanced symbol equations
1
(d)     the amount of oxygen needed to react with the lactic acid formed
allow the amount of oxygen needed to break down
or oxidise the lactic acid
1
[8]