web viewthe neurons and other structures are arranged in a fixed pathway in the spinal reflex arc....
TRANSCRIPT
B6 Brain and Mind
Name:-
Target grade:-
CAG:-
Question overview
Question Topic Mark % Grade Date
B6a i Simple reflexes /5
B6a ii Simple reflexes /1
B6b CNS /7
B6c Nervous coordination /7
B6d Neurons /1
B6ei Synapses /4
B6eii Synapses /5
B6eiii Synapses/6
B6f Hormonal communication
B6gi Our brains /1
B6gii Our brains/2
B6h Conditioning /3
B6i Memory /10
Colour code each subtopic using pencils, on target = orange, above = green, below = red.
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B6 ai – Simple reflexes 13Jan 4a/b
Mirek blinks when he gets dust in his eyes.
(a) Blinking is a reflex action.Name two features of blinking that are typical of a reflex action.
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(b) The spinal reflex arc involves a number of structures.Look at the structures, A, B, C, D and E, in the diagram of a spinal reflex arc.
The arrows show the direction of the impulse.
(i) What are the structures found in the spinal reflex arc?Write the correct name of each structure in the boxes next to letters, A, B, C, D and E, inthe table.
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(ii) The neurons and other structures are arranged in a fixed pathway in the spinal reflex arc.Why is this an advantage?Put a tick (✓) in the box next to the correct answer.
B6aii – Simple reflexes 12June 1b
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B6b – CNS June13 6a/b
(ii) The fatty sheath speeds up the electrical impulses along neurons. It also insulates each neuron from
neighbouring neurons. Suggest why this insulation from neighbouring neurons is an advantage.
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B6c – Nervous coordination June12 1d
(d) Other reflexes involve the spinal cord. In these reflexes, the impulses travel along a spinal
reflex arc.
(i) Write down two features of a spinal reflex arc that allow the response to be very fast.
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(ii) Rachel has an injury to her spinal cord just above her waist. She cannot walk because
she cannot make her legs move. A doctor tests Rachel’s knee jerk reflex and finds that it still works, even
though she cannot walk.
Use information about the pathways followed by nerve impulses to suggest an explanation
for these observations.
The quality of written communication will be assessed in your answer.
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B6d – Neurons 12June 1c5
(c) Damage to the fatty sheath around neurons leading to and from the eye can cause vision problems.
Complete the sentences to explain this.
The fatty sheath surrounds the .......................................... of a neuron.
Neurons in the optic nerve that have lost their fatty sheath will transmit nerve impulses
more .......................................... . This could cause vision problems. [1]
B6ei – Synapses 13Jan 5a/b
The human brain has billions of neurons.Impulses are transmitted across synapses in the brain.
(a) Identify two features of synapses to explain how impulses travel in only one directionbetween adjacent neurons.
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(b) Ecstasy is a drug. Complete the sentences about Ecstasy and the brain. Use words from the list.Each word can be used once, more than once or not at all.blocksdecreasesincreasesopensproducedquicklyremovedsecretedslowlystays the same
Ecstasy ...................................... sites in the brain’s synapses.
These sites are where the transmitter substance, serotonin, is ................................. .
As a result, the concentration of serotonin .................................................... in each synapse.
The frequency of impulses transmitted across each synapse.................................................... . [2]
B6eii – Synapses June12 2b/c
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(b) The brain contains billions of synapses.Suggest why an impulse can only travel in one direction across a synapse.
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(c) Serotonin is a chemical that is released at synapses in the brain. When a nerve impulse arrives at a
synapse, serotonin is released from the neuron. The serotonin allows the nerve impulse to be transmitted
across the synapse. The serotonin is then reabsorbed into the first neuron so that it can be released again
when the next impulse arrives. A new antidepressant drug stops the serotonin from being reabsorbed into
the first neuron. The average (mean) dose of the drug over five days must be greater than 10 mg to cause
this effect. A patient takes part in two trials, A and B. In trial A the patient takes the drug each day for five
days. After a rest period of one week, the patient starts trial B and again takes the drug each day for five
days.
The doses taken in trial A and trial B are shown in the tables.
B6e iii – Synapses June13 6C
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(c) Jimmy’s teacher tells him that a synapse is found between a sensory neuron and a relay
neuron in a spinal reflex arc. An electrical impulse travels along the sensory neuron and reaches the
synapse. Describe what happens at the synapse and suggest why the impulse cannot travel back from
the relay neuron to the sensory neuron.
The quality of written communication will be assessed in your answer.
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B6gi – The Brain June12 2a
B6gii – Brain June12 2d
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(d) Scientists can map the regions of the human brain using different techniques.
Name one of these techniques and discuss the ethical issues associated with it.
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B6h – Conditioning 13Jan 4c
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B6i – Memory 13Jan 5c/d/e
(c) Alzheimer’s disease affects the brain. In early stages of the disease, the most common symptom is the
inability to acquire new memories.
Suggest which part of the brain is most directly affected by this disease in the early stages.
answer ......................................................... [1]
(d) A team of scientists is investigating the ability of humans to remember information.
The scientists ask three groups of people to remember a series of ten numbers.
The scientists conclude that they cannot be sure of the correlation between noise levels andthe ability to recall number sequences.
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Use the results in the table to support and to challenge this conclusion.
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(e) Different models have been proposed to explain how memory works.Describe the multi-store model for memory and show how the data collected in thisinvestigation supports this model.You can use the space provided to draw a model if this will help your explanation.The quality of written communication will be assessed in your answer.
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