1. In boys, iron deficiency occurs due to  cellshormonesmuscle spurtpubertythroat .
2. the secretions of endocrine glands without ducts which secrete them directly into the bloodstream is called  cellshormonesmuscle spurtpubertythroat.
3.Adam's Apple is the protruding part of the  cellshormonesmuscle spurtpubertythroat.
4.Glands are the group of  cellshormonesmuscle spurtpubertythroat which secrete hormones.
5.The chemical substances secreted in the body are termed as  cellshormonesmuscle spurtpubertythroat.
6.The period at which an organism attains sexual maturity is  cellshormonesmuscle spurtpubertythroat.