BIOL 221 Lab Review

Front

What is the first step to take in any laboratory emergency?

Back

Turn off the Bunsen burners.

Front

What is the purpose of a wet mount in microscopy?

Back

To observe motile organisms.

Front

What term describes bacteria that are arranged in chains?

Back

Strepto.

Front

What is the correct order of steps in a Gram stain procedure?

Back

3 - 4 - 1 - 5 - 2 (Fixation - Stain with Crystal Violet - Iodine treatment - Decolorizer - Stain with Safranin).

Front

What material is used to seal Petri plates to prevent contamination?

Back

Parafilm.

Front

What is the role of iodine in the Gram staining process?

Back

Iodine acts as a mordant, helping to fix the crystal violet dye to the bacterial cell wall.

Front

What is the difference between prokaryotic and eukaryotic cells?

Back

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have both.

Front

What is the significance of using a decolorizer in the Gram staining process?

Back

The decolorizer differentiates between Gram-positive and Gram-negative bacteria based on their cell wall structure.

Front

What type of organisms can be observed using a wet mount?

Back

Motile organisms such as protozoa and some bacteria.

Front

What is the function of Safranin in the Gram staining procedure?

Back

Safranin is used as a counterstain to visualize Gram-negative bacteria after decolorization.