Q1.          (a)     Give three receptors which a mouse might use to detect food under natural conditions.
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(3)
(b)     Whilst observing mouse behaviour, a student drops a pen near the mouse’s cage. The mouse jumps at the noise.
          Describe, as fully as you can, the processes by which the mouse responds to the stimulus of the dropped pen.
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(6)
(Total 9 marks)

Q2.          

          The diagram shows how the blood sugar level is controlled in the body.
          Explain fully what would happen if somebody ate some glucose tablets.
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(Total 4 marks)
Q3.          A dog runs across the road in front of a car. The driver slams her foot on the brakes.
(i)      Explain how the nervous system brings about this response.
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(4)

(ii)      Explain why alcohol consumption would affect the driver’s response.
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(1)
(Total 5 marks)

 

Q4.         The diagram shows the nervous pathway used to coordinate the knee-jerk reflex.
When the person is hit at point P, the lower leg is suddenly raised.

(a)     Name neurones A, B and C.
A ....................................................................................................................
B ....................................................................................................................
C ....................................................................................................................
(3)

(b)     The receptor in the muscle in the leg is sensitive to a stimulus.
Suggest the stimulus.
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(1)

(c)     Describe what happens at the synapse during this reflex.
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(3)
(Total 7 marks)

 

Q5.          

(a)     (i)      Where are hormones produced?
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(1)
(ii)     How do hormones move around the body?
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(1)

(b)     Insulin is a hormone.
(i)      Where is insulin produced?
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(1)

(ii)     Explain the role of insulin in controlling blood sugar levels.
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(4)
(Total 7 marks)

 

Q6.          The doctor is testing the child’s nervous system by tapping the tendon just below the knee.
This pulls cells which are sensitive to stretching.

(a)     What are cells which are sensitive to stimuli called?
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(1)

(b)     These cells send information to the spinal cord.
          In what form is this information sent?
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(2)

(c)     The healthy response to the stimulus is the straightening of the leg.
What is the effector in this response?
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(1)

(d)     This response is one example of a reflex action.
Describe one other example of a reflex action in terms of:
stimulus  →  receptor  →  coordinator  →  effector  →  response
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(5)
(Total 9 marks)

 

Q7.          A person accidentally touches a hot pan.
Her hand automatically moves away from the pan.
The diagram shows the structures involved in this action.

(a)     Describe fully how the structures shown in the diagram bring about this reflex action.
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(6)

(b)     (i)      The nerve pathway in this reflex action is about 1.5 metres in length. A nerve impulse travels at 75 m s–1.
Use this information to calculate the time taken for this reflex action to occur.
Show clearly how you work out your answer.
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Time intervals ....................................... s
(2)

(ii)     The actual time interval is longer than the interval you have calculated in part (i).
Suggest an explanation for the difference.
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(1)
(Total 9 marks)

 

Q8.          The diagram shows the nervous pathway which is used to coordinate the knee-jerk reflex. When the person is hit at point P, the lower leg is suddenly raised.

(a)     (i)      Name the type of neurone labelled A. .............................................................
(1)

(ii)     On the diagram, draw arrows next to the neurones labelled A and B to show the direction in which an impulse moves in each neurone.
(1)

(b)     How is information passed across the synapse at C?
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(1)

(c)     On the diagram, label the effector with the letter X.
(1)
(Total 4 marks)

 

Q9.          The graph below shows the effect of a high carbohydrate diet on the stored carbohydrate in the muscles.

          Diet A    –     High carbohydrate diet, started after several days of eating a
                     diet without carbohydrate.
Diet B     –     High carbohydrate diet, started after normal mixed diet.
Diet C     –     Normal mixed diet.

          What advice would you give the athlete about the best diet preparation for a long race? Explain why you would give this advice.
          Diet ......................................................................
          Explanation
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(Total 2 marks)

 

##
          Read the following passage which is from an advice book for diabetics.

Insulin Reactions
Hypoglycaemia or ‘hypo’ for short, occurs when there is too little sugar in the blood.
It is important always to carry some form of sugar with you and take it immediately you feel a ‘hypo’ start. A hypo may start because:
•   you have taken too much insulin, or
•   you are late for a meal, have missed a meal altogether, have eaten too little at a meal, or 
•   you have taken a lot more exercise than usual.
The remedy is to take some sugar.
An insulin reaction usually happens quickly and the symptoms vary – sweating, trembling, tingling of the lips, palpitations, hunger, pallor, blurring of the vision, slurring of speech, irritability, difficulty in concentration.
Do not wait to see if it will pass off, as an untreated ‘hypo’ could lead to unconsciousness.	

(a)     Many diabetics need to take insulin.
(i)      Explain why.
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(2)

(ii)     Explain why there is too little sugar in the blood if too much insulin is taken.
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(3)

(iii)     Explain why there is too little sugar in the blood if the person exercises more than usual.
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(3)

(b)     Suggest why sugar is recommended for a ‘hypo’, rather than a starchy food.
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(3)

(c)     Explain how the body of a healthy person restores blood sugar level if the level drops too low.
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(3)

(d)     Explain, using insulin as an example, what is meant by negative feedback.
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(3)
(Total 17 marks)

 

Q11.          The hormone insulin is a protein. Insulin is produced in the pancreas and controls blood glucose concentration.
(a)     Which organ in the body monitors blood glucose concentration?
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(1)

(b)     We now know that a lack of the hormone insulin causes diabetes. In the early twentieth century there was no known cure for diabetes.
Frederick Banting and Charles Best carried out a number of experiments on dogs.
          In the first experiment they removed part of the pancreas from a healthy dog (dog A). They ground up the pancreas tissue and injected an extract into dog B, whose pancreas had been removed to make it diabetic. Dog B’s diabetes was not cured.
          Banting thought that an enzyme produced in the pancreas of dog A had digested the hormone before it was injected.
Name the enzyme that might have been responsible for digesting the hormone.
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(1)

(c)     In the second experiment with another healthy dog, Banting and Best tied off the duct which normally carries digestive enzymes out of the pancreas. This did not kill the dog.

(i)      The dog survived even though enzymes from the pancreas could not digest food in the intestine.
Explain why the dog survived.
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(1)

(ii)     As a result of these experiments, a method was developed to extract insulin from the pancreas.
Insulin is used to treat humans with diabetes.
The amount of insulin injected needs to be carefully controlled.
Explain why.
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(1)

(d)     Evaluate the use of dogs in experiments of this type.
Remember to include a conclusion to your evaluation.
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(3)
(Total 7 marks)

 

Q12.          The diagram shows a section through the spinal cord.

(a)     Coordination of a reflex movement of the arm, in response to the hand touching a hot object, involves three neurones. One of these, the relay neurone, is shown in the diagram. Complete the nerve pathway between the receptor and the muscle on the diagram by drawing and labelling:
(i)      the sensory neurone; 
(ii)     the motor neurone.
(2)

(b)     The nerve pathway linking the heat receptor in the hand with the arm muscle is about 
1.5 metres in length. It would take the nervous impulse 0.02 seconds to travel this distance along a neurone. However, it takes about 0.5 seconds for the arm to start moving during the reflex response to the heat stimulus.
          Explain the difference.
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(2)
(Total 4 marks)

 

M1.          (a)     light/eye
smell/nose
taste/chemical/tongue 
for 1 mark each
3

(b)     6 of e.g.
receptors in ear detect sound waves/vibrations
impulses/electrical signals to brain
brain co-ordinates response
impulses sent along nerves
to muscles/effectors which contract to bring about response
any 6 for 1 mark each
6
[9]

 

M2.          idea:
glucose level rises
pancreas releases insulin
glucose → glycogen (in liver)/removes xs glucose
glucose level falls/returns to normal
for 1 mark each
[4]

 

M3.          (i)      eyes as sense organs/detector/receptors in eye, 
electrical signals (impulses),
to co-ordinator,
then to leg muscles/effector
for 1 mark each
4

(ii)      affects the nervous system and slows down the reactions
for 1 mark
1
[5]

 

M4.          (a)     ignore nerve / neuron(e) throughout
A sensory
accept afferent
1

B motor
accept efferent
1

C relay
accept intermediate
1

(b)     stretch
allow pressure / pull / tension (in muscle)
allow a hit at (point) P
ignore pain
1

(c)     any three from:
•        chemical (release)
accept neurotransmitter / acetylcholine
•        diffuses (across the gap / synapse)
•        transmits impulse / information (across synapse)
allow transmits signal / message
•        between neurones / nerve cells / named
if named, must be either sensory / A to relay / C or relay / C to motor / B
allow ‘to the next neurone‘
3
[7]

M5.          (a)     (i)      endocrine glands or endocrine system
allow a specific named gland
1

(ii)     (dissolved) in the blood(stream) or plasma
1

(b)     (i)      pancreas or islets of Langerhans
1

(ii)     (it or insulin) lowers blood sugar level [1]
         (by) (speeding up or increasing)
conversion of glucose to glycogen [1]
         in the liver [1]
         (and) speeding up or increasing uptake of glucose by body cells [1]
4
[7]

 

M6.          (a)     receptors
for 1 mark
1

(b)     electrical/nerve
signals/impulses
for 1 mark each
2

(c)     muscle
for 1 mark
1

(d)     correct description of:
stimulus
receptor
co-ordinator
effector
response
for 1 mark each
5
[9]

 

M7.          (a)     stimulus / heat detected by temperature receptors in skin
1
impulses travel along sensory neurone to spinal cord / CNS
1
chemical transmission across synapse
1
via relay neurone
1
impulses to muscle / effector via motor neurone
1
muscle / effector contracts, moving the hand away
1

(b)     (i)      0.02 s
correct answer gains 2 marks
if answer incorrect, evidence of 1.5 / 75 gains 1 mark
2

(ii)     impulse slowed down because of time taken for
diffusion of the chemical across the synapse
1
[9]

 

M8.          (a)     (i)      sensory / afferent
1
(ii)     on diagram:
         arrow (next to neurone A) pointing towards spinal cord
and
arrow (next to neurone B) pointing towards muscle
1

(b)     chemical (released) or neurotransmitter
or by diffusion
accept correct named example of a neurotransmitter
1
(c)     on diagram:
          X labelling muscle or motor end plate
do not accept on stretch receptor
1
[4]

 

M9.          follow diet A because it gives the highest proportion of stored sugar in the muscles
for 1 mark each
[2]

 

M10.          (a)     (i)      blood sugar rises because insufficient insulin secreted by body
for 1 mark each
2

(ii)     increase in rate of conversion of glucose to glycogen
in liver
for 1 mark each
3

(iii)     muscles use more glucose from blood in respiration to release
energy needed for exercise
for 1 mark each
3

(b)     3 of    
         sugar soluble
         therefore absorbed
         quicker than starch
         which has to be digested
any 3 for 1 mark each
3

(c)     increased secretion of glucagons by pancreas
results in increases rate of conversion of glycogen into glucose
for 1 mark each
3

(d)     3 of eg
         higher blood sugar level results in increased secretion of insulin
         effect of insulin is to lower blood sugar 
         which in turn reduces rate of insulin secretion
         overall result is to keep fluctuations in sugar level to a minimum
any 3 for 1 mark each
3
[17]

 

﻿
M11.          (a)     pancreas
1
(b)     protease
allow proteinase
1
(c)     (i)      (same) enzymes / named enzymes produced in other parts /
named parts of digestive system
if named, enzymes and part must be correct
1
(ii)     diet / activity varies / amount of glucose in blood varies
accept too much insulin leads to coma / hypo / low blood sugar
accept too little insulin leads to coma / hyper / high blood sugar
1
(d)     any two from:
          pros
•        less / no experimentation on humans
•        dogs (more) similar to humans (than lower / named organisms)
•        it allows us to find a treatment or improves medical understanding
accept allows us to find a cure
          cons
•        harmful / cruel to dogs
accept kills dogs
•        dogs may not be (metabolically) like humans
2
          conclusion justified by argument
1
[7]

 M12.          (a)     

sensory neurone correctly drawn and labelled
from receptor + via dorsal root + cell body in 
ganglion + synapse to relay neurone
1
motor neurone correctly drawn and labelled
to muscle + via ventral root + same shape as 
relay neurone + synapse with relay neurone 
OR correct pathways for both neurones given 
(ie without synapse or cell bodies) and labelled, 
or correctly drawn but unlabelled = 1 mark for this part)
1

(b)     any two from:
reference to synapses / gaps between neurones
extra time for release / movement of chemical
extra time for development of muscle ‘tone’ / tension
2
[4]