AQA GCSE Biology (8461), Higher tier · Homeostasis and response › Hormonal coordination in humans
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Adrenaline and thyroxine are two hormones. Name the gland that produces thyroxine.
Thyroid gland
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Adrenaline and thyroxine are two hormones.
(a) Which gland produces adrenaline? Tick (✓) one box.[1]
Adrenal gland
Pancreas
Pituitary gland
Thyroid gland
(b) Adrenaline is released in times of fear or stress. Give two effects of adrenaline on the body.[2]
(c) Name the gland that produces thyroxine.[1]
(d) Thyroxine stimulates the basal metabolic rate. Give one other role of thyroxine in the body.[1]
Show the answer and mark scheme
(a)Answer: Adrenal gland
(b)Answer: It increases the heart rate and boosts the delivery of oxygen and glucose to the brain and muscles
increases heart rate
increases the delivery of oxygen / glucose to the brain / muscles
(c)Answer: Thyroid gland
thyroid (gland)
(d)Answer: It is important in growth and development
growth / development
Question 2Medium5 marks
Cortisol is a hormone released by the adrenal glands when a person is under stress. Its release is controlled like this: • the pituitary gland releases a hormone called ACTH • ACTH stimulates the adrenal glands to release cortisol • a high concentration of cortisol in the blood causes the pituitary gland to release less ACTH.
(a) Describe what happens to the release of ACTH and cortisol if the concentration of cortisol in the blood falls below normal.[2]
(b) Which statement describes negative feedback? Tick (✓) one box.[1]
A change in a level causes a response that makes the change bigger
A change in a level causes a response that reverses the change
A level is kept constant by the nervous system only
Hormones are released only when a person is under stress
(c) Some people take tablets containing a drug that acts like cortisol for a long time. Suggest what happens to the amount of cortisol made by their own adrenal glands. Explain your answer.[2]
Show the answer and mark scheme
(a)Answer: The pituitary gland releases more ACTH, which stimulates the adrenal glands to release more cortisol, so the cortisol concentration rises back towards normal
the pituitary gland releases more ACTH
so the adrenal glands are stimulated to release more cortisol, and the cortisol concentration rises back towards normal
(b)Answer: A change in a level causes a response that reverses the change
(c)Answer: The drug acts like a high concentration of cortisol, so the pituitary gland releases less ACTH; the adrenal glands are stimulated less and make less of their own cortisol
the drug acts like a high cortisol concentration, so the pituitary gland releases less ACTH
so the adrenal glands are stimulated less and make less of their own cortisol
Question 3Hard8 marks
The thyroid gland needs iodine from the diet to make thyroxine. The pituitary gland releases TSH, which stimulates the thyroid gland to release thyroxine. TSH also stimulates the cells of the thyroid gland to grow and divide.
(a) People whose diet contains too little iodine often develop a swelling of the thyroid gland in the neck, called a goitre. Use the information to explain why.[3]
(b) Children who do not get enough iodine may grow more slowly. Suggest why.[2]
(c) In one region, 32% of 2500 children had a goitre. Salt with added iodine was then introduced. Five years later, 6% of 2800 children in the region had a goitre. Calculate the decrease in the number of children with a goitre.[3]
Show the answer and mark scheme
(a)Answer: Too little thyroxine is made; the low thyroxine concentration no longer inhibits the pituitary gland, so it releases more TSH; TSH stimulates the thyroid gland to grow
less thyroxine is made (without iodine)
low thyroxine concentration causes the pituitary gland to release more TSH / less inhibition of TSH release
(more) TSH stimulates the thyroid gland to grow (and swell)
(b)Answer: They make less thyroxine, and thyroxine plays an important role in growth and development
less thyroxine is produced
thyroxine is needed for (normal) growth and development / to stimulate metabolic rate