The following flow chart shows a feedback mechanism related to parathyroid hormone - VCE - SSCE Biology - Question 13 - 2012 - Paper 1
Question 13
The following flow chart shows a feedback mechanism related to parathyroid hormone. Parathyroid hormone acts on various parts of the body and stimulates an increase ... show full transcript
Worked Solution & Example Answer:The following flow chart shows a feedback mechanism related to parathyroid hormone - VCE - SSCE Biology - Question 13 - 2012 - Paper 1
Step 1
a rise in the level of calcium in urine.
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Answer
This statement is incorrect as parathyroid hormone aims to increase blood calcium levels, not calcium in urine.
Step 2
an increase in absorption of calcium by bones.
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Answer
This statement is misleading. While parathyroid hormone does influence bone remodeling, its primary action in response to low blood calcium focuses on increasing calcium release from the bones.
Step 3
a reduction in the activity of the parathyroid glands.
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Answer
This statement is false; the parathyroid glands release more hormone when blood calcium levels are low.
Step 4
increased absorption of calcium from the intestines.
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Answer
This statement is correct. The parathyroid hormone promotes the activation of vitamin D, which enhances calcium absorption from the intestines.
