5 (a) Motor neurones are found in the nervous system - Edexcel - GCSE Biology Combined Science - Question 5 - 2021 - Paper 1
Question 5
5 (a) Motor neurones are found in the nervous system.
Figure 8 shows a motor neurone.
(i) Draw an arrow on Figure 8 to show the direction of travel of an electric... show full transcript
Worked Solution & Example Answer:5 (a) Motor neurones are found in the nervous system - Edexcel - GCSE Biology Combined Science - Question 5 - 2021 - Paper 1
Step 1
(a)(i) Draw an arrow on Figure 8 to show the direction of travel of an electrical impulse along the motor neurone.
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Answer
An arrow should be drawn from left to right on Figure 8 to indicate the direction of the electrical impulse traveling along the motor neurone.
Step 2
(a)(ii) Name both structure K and structure L.
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Answer
K - myelin (sheath)
L - axon
Step 3
(b)(i) Describe how an impulse passes from the relay neurone to the motor neurone.
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Answer
The impulse in the relay neurone triggers the release of a chemical neurotransmitter. This neurotransmitter then diffuses across the synapse and triggers a new impulse in the motor neurone.
Step 4
(b)(ii) Explain the function of a reflex arc.
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Answer
The reflex arc is a process that occurs in response to danger, which bypasses the brain for a quicker response. It allows for a faster transmission of electrical impulses, leading to rapid actions that protect the body from harm, such as pulling back from a hot surface.
Step 5
(c)(i) Which is the median result for these students?
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The median reaction time for the students is 210 milliseconds, which is the middle value when the reaction times are arranged in order.
Step 6
(c)(ii) Describe how the scientist could compare the reaction times of these students when they respond to red squares turning into yellow squares.
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Answer
The scientist should measure the reaction times using red squares, while keeping all other variables constant (e.g., using the same setup as with the blue squares). Measurements should be repeated for each student. Finally, the scientist should calculate the mean reaction time from the results gathered.
