[BIO 120.12] Final Exam - Exercises 3-4

TRUE

T/F: Endospores are metabolically dormant

FALSE

T/F: Endospores are metabolically vegetative

TRUE

T/F: Endospores function only for protection and survival, but not for metabolism and reproduction

FALSE

T/F: Endospores function for protection, survival, and metabolism, but not for reproduction

FALSE

T/F: Endospores function for protection and reproduction, but not for metabolism

Endospore

Spore that develops within the parent bacterial cell (vegetative cell/sporangium)

TRUE

T/F: Endospores are chemically more complex than the vegetative cell

FALSE

T/F: Vegetative cells are chemically more complex than the endospores

Calcium, Dipicolinic Acid

Endospores are high in what nutrients?

Heat resistant, Thick walled, Highly refractile, Resistant to physical and chemical agents

What are the 4 characteristics of endospores (heat tolerance, thickness, refraction, resistance)

TRUE

T/F: Endospores are resistant to both physical and chemical agents

FALSE

T/F: Endospores are resistant only to physical agents, but may be broken by chemical agents

Ribosomes, Nucleoid, Core Wall, Cortex, Spore Coat, Exosporium

What are the parts of the endospore shown?

Central, Subterminal, Terminal, Swollen Sporangium

Label the endospore positions in the mother cell

Axial filament formation, Septum formation and forespore development, Engulfment of forespore, Cortex formation, Coat Synthesis, Completion of coat synthesis + Increase in refractility and heat resistance, Lysis of sporangium + spore liberation

What are the 7 stages of endospore formation?

Schaeffer-Fulton Procedure

Endospore staining is alternatively called as?

Prepare smear → Flood with malachite green for 15 minutes → Rinse with distilled water → Cover smear with safranin for 30 seconds → Pour off excess and rinse with distilled → Observe under OIO

What are the steps for endospore staining?

Steaming helps stain permeate endospore

What is the purpose of steaming in some endospore staining procedures?

Cold Method

What method of endospore staining uses no steam?

Reduces exposure to toxic effects of malachite green

What is the purpose of the cold method?

TRUE

T/F: In the endospore staining technique, both vegetative cells and endospores are stained green during the flooding of malachite green

FALSE

T/F: In the endospore staining technique, only vegetative cells are stained green during the flooding of malachite green

TRUE

T/F: In endospore staining technique, water serves as a decolorizer to decolorize vegetative cells

FALSE

T/F: In endospore staining technique, 95% ethanol serves as a decolorizer to decolorize vegetative cells

FALSE

T/F: In endospore staining technique, water serves as a decolorizer to decolorize both vegetative cells and endospores

Safranin

What is the counterstain used in endospore staining?

Bacillus anthracis, Bacillus cereus, Clostridium botulinum, Clostridium tetani

What are 4 examples of medically important endospore forming bacteria?

Bacillus anthracis

Endospore forming bacteria that is known to be a bioterrorism agent

TRUE

T/F: Bacillus anthracis infection is often obtained through contact with infected animals

FALSE

T/F: Bacillus anthracis infection is often obtained through fecal-oral route

Bacillus cereus

Endospore forming bacteria that is a common rice contaminant

Log phase or sporulation

When does toxin production of B. cereus occur?

Localized infections, Systemic infections, Food poisoning, Food infection

What are 4 diseases that B. cereus can cause?

Clostridium botulinum

Endospore forming bacteria that can be occasionally found in feces and honey

Clostridium botulinum

A major potential agent for bioterrorism and biologic warfare

Clostridium tetani

Endospore forming bacteria that is known to cause toxemia

4-5 days to 3 weeks

How long can tetanus or toxemia last?

Self propulsion

Motility refers to movement of cells by some form of ___.

Exploit new resources, from unfavorable conditions

What are two benefits of motility?

Swarming

Multicellular surface movement powered by rotating helical flagella

Swimming

Individual movement in liquid powered by rotating flagella

Twitching

Surface movement powered by the extension and retraction of pili

Gliding

Active surface movement that does not require flagella or pili and involves focal adhesion complexes

Sliding

Passive surface translocation powered by growth and facilitated by a surfactant

Surfactant

What facilitates sliding?

Focal adhesion complexes

Gliding is unique as it involves?

Sliding

Spreading by growth

Flagella

Extremely thin, hairlike appendages for locomotion

Electron Microscope

What can be used to see flagella directly?

Swimming

What motility type is flagella helpful in?

Flagella

What bacterial appendage is useful in taxonomic identification of bacteria?

Pilus

Thin (2–10 nm in diameter) filamentous structures made of protein that extend from the surface of a cell

TRUE

T/F: Pili is typically long and only one or a few pili are present on the surface of a cell

FALSE

T/F: Pili is typically long and numerous and surface on the cell

Hanging Drop Technique, Motility Band, Flagella Staining

What are the 3 Tests for Motility

Hanging Drop Technique

Simple method to observe motility

TRUE

T/F: Hanging drop technique involves observations of living microorganisms

FALSE

T/F: Hanging drop technique involves observations of dead microorganisms

Brownian Movement

Vibration of the cell due to collision with water molecules

Brownian Movement

Oscillating and quivering movement

True Motility

Allows the cell to move in different directions

True Motility

Changes in position with respect to neighboring cells

Semi-solid medium

What kind of medium is needed if we want to do a motility band experiment?

TRUE

T/F: Motility band requires a culture medium with low agar concentration

FALSE

T/F: Motility band requires a culture medium with no agar

Allows bacteria to move away from the line of inoculation, Must be able to support growth, Low concentrations of metabolizable substrate

Why do we require a semi solid medium in motility bands?

EDTA

What substance enhances motility through its chelating action?

Zn, Cu

What heavy metals can abolish motility?

Clump on surface, leaving rest of medium clear, Growth spreads out only in one direction, Sharply differentiated edge between the growth and the agar

What are the observations for a non-motile motility band?

Move down from the surface of the medium and disperse throughout the media, Diffuse growth radiating from the stab line, Medium is slightly turbid, Growth throughout the tube

What are the observations for a motile motility band?

Thickness of flagella must be increased

In flagella staining, what must be done to observe flagella in a light microscope?

Mordants like tannic acid and potassium alum

What is used to coat flagella in flagella staining?

Staining with pararosaniline (Leifson method) or basic fuchsin (Gray method)

What are the 2 options for flagella staining?

TRUE

T/F: Flagella staining does not involve heat fixing

FALSE

T/F: As a staining technique, flagella staining involves heat fixing

Flagella is denatured by heat

Why do we not do heat fixing in flagella staining?

Taxis

Ability to sense and respond to stimuli in their environments

Osmotaxis

A response to an ionic strength gradient

Ionic strength gradient

Osmotaxis is a response to what gradient?

O2 gradient

Aerotaxis is a response to what gradient?