Chapter 3 & 4 Assignments
What general type of stain is used to separate types of bacteria based on their cellular structures?
differential
The differential stage of the Gram stain is the application of ________.
ethanol
True or False: All bacteria can be classified as either gram-positive or gram-negative.
false
True or False: Bacteria are larger than human cells.
false
True or False: Bacteria are only visible with an electron microscope.
false
True or False: Endospores function in the reproduction of bacterial genera such as Bacillus and Clostridium
false
True or False: Most bacterial genera are capable of forming endospores
false
True or False: The presence of flagella can be determined by a Gram stain.
false
True or False: The thinner peptidoglycan layer of gram-positive bacteria allows the crystal-violet-iodine complex to leave the cell.
false
True or False: When a spore germinates, it gives rise to two vegetative cells.
false
Which of these organisms has the best potential to survive in extreme environments?
fungi
How long can spores survive?
million of years
When spore formation begins, the vegetative cell is referred to as the ________.
mother cell
Why must fresh cells be used when performing a Gram stain?
old cells may not gram-stain properly
Which of the following is considered an "adverse condition" by most bacteria
pH=4
The cortex is formed from ________.
peptidoglycan
In the final step of spore formation, a ________ coat forms around the cortex.
protein
When ethanol is applied correctly, gram-positive cells appear ________ and gram-negative cells appear ________.
purple; colorless
The term used to describe a cluster of spherical bacteria is _________.
staphylococci
Which of the following diseases is NOT caused by a spore-forming bacterium?
strep throat
The developing spore is surrounded by ________.
the membrane of the mother cell
Yeasts are _______ fungi, and molds are ________ fungi.
unicellular; filamentous
When is sporulation initiated by spore-forming bacteria?
when nutrients are depleted or conditions becomes= adverse
If the Gram's iodine step was skipped in this technique, what would likely be seen under the microscope?
Most cells would appear red/pink
1. A vegatative cell is _____
a metabolically active cell
After Gram's iodine is added, what color do the cells appear under a light microscope?
all cells appear purple
which of the following conditions needs to be suitable for bacteria to grow
all of the choices are correct
In the next phase of spore formation, ________ enters the cortex and ________ leaves the cortex
calcium; water
Rod-shaped bacteria ________.
can be either gram positive or gram negative