What is a hormone?
Ait is a gland that is produced by the endocrine system
Cit is a chemical messenger that is produced by the excretory system
Bit is a chemical messenger that is produced by the endocrine system
Dit is a chemical messenger that is produced by an exocrine gland
Ait is a gland that is produced by the endocrine system
Cit is a chemical messenger that is produced by the excretory system
Bit is a chemical messenger that is produced by the endocrine system
Dit is a chemical messenger that is produced by an exocrine gland