MCB2289L Module 04 LearnSmart Lab Quiz

• Question 1 In a negative stain, which of the following is stained?

Answers: Cell wall

Cytoplasm

Background

Cell membrane

• Question 2 In a differential staining technique, a ______ is used to remove the primary stain from the bacterial cell wall

Answers: Mordant

Decolorizer

Secondary stain

Counterstain

• Question 3 Why might it be important to perform a Gram stain on bacterial cells?

Answers:

As part of the information used to choose an appropriate antibiotic treatment

To investigate the cell's organelles

In order to determine the species of an infectious agent

To make the bacterial grow more efficiently on nutrient media

• Question 4 In the Gram stain, the chemical that fixes dye in or on cells by forming an insoluble compound in referred to as the _______________?

Answers:

mordant

decolorizer

counterstain

primary stain

• Question 5 In order to withstand hostile conditions and facilitate survival, some bacteria produce resistant structures known as:

Answers: Ribosomes

Endospores

Centrioles

Flagella

• Question 6 Staining allows for visualization of bacterial cells because it increases contrast during microscopic imaging?

Answers: True

False

• Question 7 The purpose of heat fixation is to _______.

Answers: Adjust the morphology of the organisms on the slide

Encourage growth of bacterial cells on the slide

Inactivate and adhere microorganism placed on the slide

Harden the bacteria so that they are not destroyed by the staining procedure

• Question 8 Gram negative cell walls contain a thin layer of peptidoglycan whereas Gram positive cell walls contain a thick layer of peptidoglycan.

Answers: True

False

• Question 9 During a simple stain, what will happen in the heat fixation step is omitted

Answers: The cells will not take up the dye

The cells will be destroyed by the staining process

The cells may wash off the slide

The cell morphology will change

• Question 10 All of the following are true regarding bacterial smears EXCEPT

Answers: Preparation of bacterial smears is required for bacterial staining procedures

Bacterial smears provide scientist with the means to look at microorganisms

Bacterial smears are used to treat infectious diseases

Preparation of smears disperses bacterial cells on a slide so that individual cells can be visualized under the microscope

• Question 11 A simple stain provides enough information about a microbe to clearly identify its species:

Answers: True

False

• Question 12 ________ is used to stain the endospore in the endospore staining procedure

Answers: Methylene blue

Crystal violet

Malachite green

Safranin

• Question 13 Staining techniques do NOT provide information on which of the following structures?

Answers: Inclusions

Ribosomes

Capsule

Cell wall

• Question 14 Encapsulated organisms are difficult to directly stain because ___

Answers: The capsule easily reacts with most stains

The capsule prevents bacteria from adhering to the slide

The capsule is easily removed from the cell

The capsule is not permeable to most stains

• Question 15 Spherical cells arranged in chains are called __________.

Answers: Staphylococci

Streptobacilli

Spirillium

Streptococci

• Question 16 The first dye applied in a differential staining technique is referred to as the counterstain

Answers: True

False

• Question 17 Gram negative cells appear purple after Gram staining whereas gram positive cells appear pink

Answers: True

False

• Question 18 In the Acid-fast stain, non-acid-fast bacteria appear pink under the microscope

Answers: True

False

• Question 19 Stains are commonly used for all of the following EXCEPT Answers: The pathogen identification process

The diagnosis of disease

The classification of organisms

The treatment of disease

• Question 20 Which of the following diseases are caused by acid-fast bacterium:

Answers: HIV

Influenza

Cholera

Tuberculosis (TB)