Question 1
Which statement describes homeostasis?
- Responding to a stimulus
- Maintaining a constant internal environment
- Producing hormones in a gland
- Releasing energy from food
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Answer: B (1)
Question 2
After a meal rich in carbohydrate, the concentration of glucose in the blood rises. Name the hormone that decreases the blood glucose concentration and name the organ that secretes it.
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- insulin (1)
- pancreas (1)
Question 3
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanExplain how negative feedback keeps the blood glucose concentration close to a set point.
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- the set point is the normal level / concentration of blood glucose (1)
- a change away from the set point is detected (1)
- a response occurs that reverses the change / brings the concentration back towards the set point (1)
- for example, if too high, insulin is secreted which lowers it / if too low, glucagon is secreted which raises it (1)
- when the set point is reached the response reduces / stops (1)
- Max 4
Question 4
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanDescribe how the blood glucose concentration is controlled after a meal and several hours later, when the concentration has fallen. Refer to the pancreas, the liver, insulin and glucagon.
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- after a meal, blood glucose concentration rises and the pancreas secretes insulin (1)
- insulin causes the liver to convert glucose to glycogen (1)
- blood glucose concentration decreases (1)
- when the concentration falls too low, the pancreas secretes glucagon (1)
- glucagon causes the liver to convert glycogen to glucose, released into the blood (1)
- blood glucose concentration increases (1)
- Max 5
Question 5
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanOutline the treatment of Type 1 diabetes.
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- insulin injections (1)
- monitor / test blood glucose concentration (1)
- control the diet / amount of carbohydrate eaten (1)
- injected at mealtimes / dose matched to glucose concentration (1)
- Max 3
Question 6
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanA person exercises and their body temperature starts to rise. Which change occurs in the skin?
- The arterioles supplying the skin surface capillaries narrow
- The arterioles supplying the skin surface capillaries widen
- The hair erector muscles contract
- Shivering begins
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Answer: B (1)
Question 7
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanExplain how a mammal responds to a fall in the temperature of its surroundings, to keep its internal body temperature constant.
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- receptors detect the change / the brain coordinates the response (1)
- vasoconstriction: arterioles supplying skin surface capillaries narrow (1)
- less blood flows near the skin surface so less heat is lost (1)
- shivering: muscles contract, respiration releases heat (1)
- hair erector muscles raise the hairs to trap air (insulation) (1)
- no sweating / less sweating (1)
- Max 4