BIOL 230 Lab Exam 2 Review ('HOLY COW' Edition)

A colorful illustration of bacteria with flagella, endospores, and cell structures in a laboratory setting, emphasizing microscopic detail and diversity of bacterial shapes.

BIOL 230 Lab Exam 2 Review Quiz

Prepare yourself for the BIOL 230 Lab Exam with our comprehensive review quiz designed specifically for biology students. This engaging quiz will test your knowledge of bacterial structures, motility, and essential staining techniques.

Key Features:

50 carefully crafted questions.
In-depth coverage of major concepts.
Instant feedback on your responses.

50 Questions12 MinutesCreated by StudyingCell543

Select the components of bacterial flagellum

Filament

Hook

Basal Body

Golgi Body

The filament is the rigid helical structure that extends from the cell surface.

True

False

The hook is a flexible coupling between the filament and the basal body.

True

False

The _________ anchors the flagellum to the cell wall and cytoplasmic membrane and acts as a rotary molecular motor.

Filament

Hook

Basal Body

Golgi Body

To move forward, the flagella rotate in a clockwise direction.

True

False

To change direction (tumble), the flagella rotate in a counter-clockwise direction,

True

False

Taxis is a motile response to an environmental stimulus and functions to keep bacteria in an optimum environment.

True

False

Example of taxis include:

Phototaxis

Magnetotaxis

Chemotaxis

Hemotaxis

Example of amphitrichous.

Example of peritrichous.

Example of monotrichous.

Example of lophotrichous.

Direct observation of motility using special-purpose microscopes allow for the observation of live bacteria. The two 2 types are what?

Phase contrast microscopy

Dark-field microscopy

Electron microscopy

Prism microscopy

In order to see Flagella, special dyes are used that build up as layers of precipitate along the length of the flagella . This is known as Flagella staining.

True

False

Motility test medium may be used to detect motility. The agar concentration (0.3%) is sufficient to form a soft gel without hindering motility.

True

False

When motile organisms are stabbed into the medium, growth only occurs along the line of inoculation.

True

False

The two endospore forming genera of bacteria are what?

Bacillus

Escherichia

Pseudomonas

Clostridium

Note the green endospores within pink bacilli.

Note the endospore within the rod(Clostridium tetani) gives the bacterium a "tennis racquet" shape (arrows)

A dye or stain used to differentiate one component or cellular structure from another is what?

Differential stain

Occlusive stain

Phase stain

Gram staining is called a differential stain since it differentiates between gram-positive and gram-negative bacteria.

True

False

Describe a gram-negative cell wall.

The color of a gram-positive and a gram-negative bacterium at each step in the process.

The theory as to why gram-positive bacteria retain the crystal violet-iodine complex while gram-negative bacteria become decolorized.

Capsules help many pathogenic and normal flora bacteria to initially resist phagocytosis by the host's phagocytic cells. In soil and water, capsules help prevent bacteria from being engulfed by protozoans. Capsules also help many bacteria to adhere to surfaces and thus resist flushing. It also enables many bacteria to form biofilms. Enterobacter aerogenes; Note the colorless capsules surrounding purple bacilli.

_____________ are secreted by bacteria into the surrounding environment in order to break down larger nutrient molecules so they may enter the bacterium.

Endoenzyme

Exoenzyme

_______________ are located within the bacterium and function to further break down nutrients that come into the cell to yield energy for driving various cellular functions or to form building blocks for the synthesis of cellular components .

Exoenzymes

Endoenzymes

The enzyme called diastase can hydrolyze or break down the starch so it may enter the cell

True

False

Starch Hydrolysis by Bacillus subtilis on Starch Agar. The clear zone around the growth of Bacillus subtilis no longer contains starch to react with the iodine. The starch was hydrolized by a diastase produced by the bacterium.

No Starch Hydrolysis by Escherichia coli on Starch Agar. The starch was not hydrolized by the Escherichia coli on the left. The starch reacts with the iodine producing the dark color.

The hydrolysis of protein is termed protease and the enzyme involved is called a proteolysis. In lab 8 bacteria hydrolyze the protein casein.

True

False

The clear zone around the growth of the Bacillus subtilis on the right no longer contains casein. The casein was hydrolized by a protease produced by the bacterium.

The casein was not hydrolized by the Escherichia coli on the left. The agar remains white and opaque.

Using the pH Indicator Phenol Red to Detect Acid. What does this tube indicate about the presence of fermenting microorganisms?

They can ferment

They can't ferment

Can this microorganism ferment?

Yes

Select all that apply about this tube in relation to the fermentation of carbohydrates.

Acid end products

Gas production

Alkaline end products

Some bacteria use the enzyme tryptophanase to convert the amino acid tryptophan into molecules of indole, pyruvic acid and ammonia.

True

False

To test for indole and hydrogen sulfide production, SAM (sulfide, amonnium, motility) medium is used

True

False

Some bacteria produce hydrogen sulfide as a result of their metabolism they use sulfur as a final electron acceptor in anaerobic cellular respiration.

True

False

Interpret the hydrogen sulfide and indole results in this SIM medium tube.

(+) Indole

(-) Indole

(+) Hydrogen sulfide

(-) Hydrogen sulfide

Interpret the hydrogen sulfide and indole results in this SIM medium tube. Hint Kovac's reagent is added.

(+) Indole

(-) Indole

(+) Hydrogen sulfide

(-) Hydrogen sulfide

Catalase is the name of an enzyme found in most bacteria which initiates the breakdown of hydrogen peroxide (H2O2) into water (H2O) and free oxygen (O2). Therefore what does this sample of Staphylococcus aureus(TOP SLIDE) indicate?

(+) Catalase

(-) Catalase

Basic dye: the color portion of the dye is the _____________ion.

Negative

Positive

Acidic dye: the color portion of the dye is the _____________ion.

Positive

Negative

With a basic dye, the positively charged color ion combines with the negatively charged bacterial cytoplasm. Therefore The organism becomes _____________.

Directly stained

Indirectly stained

Negative staining

Is this a direct stain or an indirect stain?

Direct Stain

Indirect Stain

Why do we heat fix the bacteria to the slide before staining?

So the bacteria hold the stain better.

So the bacteria don’t wash off the slide.

To kill the bacteria.

All bacteria have a slight negative charge; a basic dye has the color in the positive ion. Opposite charges attract. This is the principle behind _____________________.

Indirect staining.

Why Gram-positive bacteria don’t stain pink

Direct staining

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BIOL 230 Lab Exam 2 Review ("HOLY COW" Edition)

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