Questions: Multiple Select Question Select all that apply Which of the following are characteristics of many types of dyes used to stain microorganisms? They have chromophore groups. They are able to bind cells only by covalent bonds. They do not have chromophore groups. They are able to bind cells by ionic, covalent, or hydrophobic bonds.

The answer is:

• They have chromophore groups.
• They are able to bind cells by ionic, covalent, or hydrophobic bonds.

Explanation for each option:

1. They have chromophore groups.

   • Correct. Chromophore groups are the part of the dye molecule responsible for its color. These groups absorb light at specific wavelengths, which is essential for the dye to be visible under a microscope.

2. They are able to bind cells only by covalent bonds.

   • Incorrect. Dyes can bind to cells through various types of bonds, not just covalent bonds. Limiting the binding mechanism to only covalent bonds is not accurate.

3. They do not have chromophore groups.

   • Incorrect. As mentioned earlier, chromophore groups are essential for the dye to impart color. Without chromophore groups, the dye would not be able to stain the microorganisms effectively.

4. They are able to bind cells by ionic, covalent, or hydrophobic bonds.

   • Correct. Dyes can bind to cells through different types of interactions, including ionic bonds (e.g., between positively charged dye molecules and negatively charged cell components), covalent bonds, and hydrophobic interactions.

Summary: Many types of dyes used to stain microorganisms have chromophore groups and can bind to cells through ionic, covalent, or hydrophobic bonds.