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Karnataka Board PUCPUC Science Class 11

You have learnt that a characteristic feature of endocrine system is the presence of feed back loops. - Biology

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Question

You have learnt that a characteristic feature of endocrine system is the presence of feed back loops. By this what is meant if hormone A stimulates gland ‘X’ to secrete hormone B, the production of ‘A’ could be modified when the level of B changes in our blood. An example is the relation between hormones LH and estrogen (E2). An old woman exhibits the following features. High levels of LH in blood but low levels of E2 in the blood. Another woman exhibits high level of LH in blood and also high level of E2 in the blood. Where is the defect in both these women? Provide suitable diagram to support this answer.

Short/Brief Note
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Solution

If an old woman exhibits high levels of LH in her blood but low levels of E2 in the blood then it may be due to any abnormality in the anterior pituitary. If an old woman exhibits high levels of LH in blood and high levels of E2 in the blood then it may be due to any abnormality in the anterior pituitary or ovary.

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Chapter 22: Chemical Coordination and Integration - Exercises [Page 127]

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NCERT Exemplar Biology [English] Class 11
Chapter 22 Chemical Coordination and Integration
Exercises | Q 9. | Page 127

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