The purpose of a mordant in the Gram stain is to The purpose of a mordant in the Gram stain is to make the flagella visible. make gram-negative cells visible. make the bacterial cells larger. prevent the crystal violet from leaving the cells. remove the simple stain.

prevent the crystal violet from leaving the cells

Explanation:

Mordant is a chemical substance that is used during the staining procedure in order to identify the bacteria. The mordant fixes the dye on to the tissue when it forms the complex with the stain added during the staining procedure.

During gram staining, the mordant added is iodine which forms a complex with the crystal violet and attaches to the cell wall layer. This attachment does not allow the dye to leave the cell and help in differentiating the bacterial strains.

Thus, the selected option is correct.

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.