Dehydration is the correct answer because the formation of both peptide and glycosidic bonds involves the removal of a water molecule. Let's explore this in more detail:

Peptide Bonds:
- A peptide bond is a covalent bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid.
- The formation of a peptide bond involves a condensation reaction, also known as a dehydration synthesis reaction.
- In this reaction, the carboxyl group of one amino acid undergoes a nucleophilic attack by the amino group of another amino acid.
- The resulting intermediate is an unstable tetrahedral intermediate, which then undergoes dehydration.
- During dehydration, a water molecule is eliminated, and the amino acids are joined together by a peptide bond.
- This process is repeated to form a polypeptide chain, which is the basis for protein synthesis.

Glycosidic Bonds:
- A glycosidic bond is a covalent bond that forms between the anomeric carbon of a sugar molecule and a hydroxyl group of another sugar molecule.
- The formation of a glycosidic bond also involves a condensation reaction or dehydration synthesis reaction.
- In this reaction, the anomeric carbon of one sugar molecule reacts with the hydroxyl group of another sugar molecule.
- The reaction results in the elimination of a water molecule, and the two sugar molecules are joined together by a glycosidic bond.
- This process is repeated to form complex carbohydrates, such as polysaccharides.

In both peptide and glycosidic bond formation, the removal of a water molecule is essential for the formation of a covalent bond between two molecules. This process is known as dehydration because it involves the loss of a water molecule. It is important to note that dehydration is a general term used to describe the removal of water in various chemical reactions, not just peptide and glycosidic bond formation.