This question was quite popular among the candidates and they had high scores. Most
candidates showed a good knowledge of the components of a reflex arc and functions
of the components.
The difference between reflex actions and voluntary actions were correctly tallied but
candidates failed to mention that reflex action is controlled by the spinal cord and hind
brain. Some candidates could not state how blood glucose is regulated by
insulin.
The expected answers are:
(b) Regulation of Blood glucose by insulin.
When the level of glucose in the blood rises; insulin is secreted from the pancreas/ Islets of Langerhans; insulin stimulates liver/fat/muscles to metabolise glucose; stimulates muscles and liver to store glucose as glycogen; promotes the buildup of fats and protein; inhibits their use as an energy source; leading to lowering of the level of glucose in the blood;
When the blood sugar level falls; pancreas releases glucagon; which stimulates the breakdown of stored nutrients/conversion of glycogen to glucose; causing the blood sugar level to normalise.
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