Describe the structure of a trna molecule.

A tRNA means a transfer RNA. It is a adaptor molecule composed of RNA having about 76 to 90 nucleotides that serves a bond between mRNA and the amino acid sequence. The structure of a tRNA consists of a 5'-terminal phosphate group, acceptor stem, D arm, anticodon arm,  T arm and bases that have been modified.

Covalent bond is the correct answer

the glands which are associated with each description is given below:

pancreas - is an endocrine and exocrine gland that secretes juices with enzymes for digestion. salivary glands- with protection and digestion in the mouth. liver- secretes bile for digestion.   lachrymal glands - secrete tears to moisten eyes and protect them from particles and infection.   sweat gland -regulates water, salt, and temperature. oil glands - to form a protective barrier on the skin.   goblet cells - secrete mucus for protection.