NEETZoologyChemical Coordination and Integration
What is the definition of hormone according to current science?
Options
- AA chemical produced by endocrine glands and released into the blood
- BNon-nutrient chemicals which act as intercellular messengers
- CChemicals produced in large amounts
- DHormones secreted by the organised endocrine glands
Correct answer
B. Non-nutrient chemicals which act as intercellular messengers
Step-by-step solution
Endocrine glands lack ducts and are hence, called ductless glands. Their secretions are called hormones. The classical definition of hormone as a chemical produced by endocrine glands and released into the blood and transported to a distantly located target organ has current scientific definition as follows: Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts. The new definition covers a number of new molecules in addition to the hormones secreted by the organ