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It is important that our body maintains a constant internal environment - OCR Gateway - GCSE Biology Combined Science - Question 11 - 2021 - Paper 1
Question 11
It is important that our body maintains a constant internal environment. Complete these sentences about maintaining a constant internal environment. You can use ea... show full transcript
Worked Solution & Example Answer:It is important that our body maintains a constant internal environment - OCR Gateway - GCSE Biology Combined Science - Question 11 - 2021 - Paper 1
Step 1
Complete these sentences about maintaining a constant internal environment.
Answer
The body needs a constant internal environment so that metabolic reactions take place at an appropriate rate.
The body needs to maintain oxygen levels so that aerobic respiration can take place.
Blood sugar levels are controlled by the hormone insulin.
Step 2
Step 3
Draw two arrows on Fig. 11.1 to show the direction the nerve impulse travels along each neurone in the arm.
Answer
One arrow should point from the 'receptors in skin' towards the 'spinal cord' (sensory to relay). The second arrow should point from the 'spinal cord' to the 'muscle' (relay to motor).
Step 4
Explain how the reflex arc prevents too much damage from the hot pan.
Answer
The reflex arc allows for a rapid response to a stimulus. When the receptors in the skin detect the heat from the hot pan, a signal is sent via the sensory neurone to the spinal cord, where it directly connects to a motor neurone. This causes an immediate withdrawal of the hand from the hot surface, preventing further damage.
Step 5
Use data from Fig. 11.2 to describe the effect of caffeine on reaction time.
Answer
From Fig. 11.2, it can be observed that the mean reaction time decreased from the time before the drink to 10 minutes after consuming the caffeine drink, indicating improved reaction time. However, the mean reaction time showed a slight increase 20 minutes after the drink, suggesting that the initial boost in reaction time may not be sustained over an extended period.