Advertisement Upgrade to remove ads

The resolving power of a microscope is described as the ability of the microscope to

view as separate two objects that are very close together

In viewing a microscopic specimen, emersion oil is used to

Improve the resolution and increase the refractive index

Which of the following microscope types would be the most useful in view unstained living cells?

Phase contrast

Basic dyes

are positively charged and bind well to DNA

Which of the following stains is considered differential

Gram stain and acid fast stain

The order of reagents in the Gram stain reaction are

crystal violet, iodine, alcohol, safranin

The acid-fast stain

uses both carbolfusion and methylene blue; stains a small group of organisms with a waxy cell envelope such as Mycobacterium

India ink is an example of

a negative stain and a capsule stain

Which term refers to bacterial morphology

Coccus, Spirilium, and Bacillus

Most hydrophilic solutes pass through the cytoplasmic membrane of bacteria via

transport proteins

LPS is found in the outer membrane of Gram-positive bacteria.

False

Which of the following bacteria lack a cell wall?

Mycoplasma pneumonia

Which is true concerning the cell wall of prokaryotes?

it helps cell maintain shape, prevents cell from bursting in high salt conditions, is composed of peptidoglycan, it is the target of some antimicrobials

A physician sends a stool sample to your lab, and wants to know if there are lactose fermenting Gram-negative microbes in the sample. How might you determine if these microbes are present or not from this mixed-microbe specimen?

Plate the specimen on MacConkey agar

A bacterial culture medium that inhibits the growth of organisms other than the one being sought is termed a

selective

All the bacterial cells that result from the replication of a single original bacterial organism are said to be

pure culture

A urine sample with more than 100,000 organisms is considered indicative of infection. A urine sample containing 5,000 bacteria, with a generation time of 30 minutes, sits for 3 hours before finally being assayed. How many bacteria will then be present within the sample after 3 hours?

5,000 x 2^6 = 320,000

A hot tub (approx. 104 F or 40 C) would most likely contain

Mesophiles

Organisms that require molecular oxygen (O2) for metabolism are referred to as

Obligate aerobes

Enzymes that destroy toxic oxygen intermediate molecules include

superoxide dismutase and catalase

Organisms that use CO2 as their source of carbon are called

Autotrophs

One would expect most strict (obligate) anaerobic organisms to have enzymes that detoxify reactive oxygen molecules.

False

All of the following are part of the cell envelope (inner and outer membrane) of Gram-Negative cells:

Phospholipids, peptidoglycan, lipid A

NOT techoic acid

You are working in a clinical laboratory in a hospital setting. You're handed a throat swab from a patient. You are told specifically that the physician is only interested in what kind Gram-positive cells present. What might you do first to go about working towards this goal?

You culture the bacteria on the swab on medium that is selective from Gram-positive cells, while suppressing the growth of Gram-negative cells.

Which of the following distinguish nucleotides of RNA from DNA?

Uracil and ribose

Bacterial flagella move in a counter-clockwise rotation during a tumbling event.

False

In doing the gram stain, you accidently forgot to stain with safranin. What would be the color of gram-negative organisms?

colorless

The 70S prokaryotic ribosome is composed of a 30S subunit and a ___ subunit

50S

Transport across the cytoplasmic membrane of prokaryotes that requires the expenditure of energy is called

active transport

Which of the following would improve the resolution of a microscope

Increasing the refractive index (D=0.61x/rsin@)

The scientist usually considered the first to see live microorganisms, which he called "animalcules", was

van Leeuwenhoek

The idea of Spontaneous Generation postulated that

Organisms could arise from non-living material

Bioremediation refers to

using bacteria to clean up pollutants

Bacteria

are normal residents on or in our body / may occupy spaces that otherwise would be occupied by pathogens

Which is usually true of bacteria

They are rods, spheres, or spirals in shape/they are usually single celled/they reproduce by binary fission/they contain a rigid cell wall of peptidoglycan

Both Eubacteria and Eukarya contain membrane bound intracellular organelles.

False

The parts of the atom that are most involved in chemical reactivity (bonding) are

Electrons

The sharing of electrons between two atoms constitutes a

covalent bond

The bonds between hydrogen and oxygen atoms within a molecule of water are

polar covalent

What type of bonding holds one strand of DNA to the complementary strand of DNA?

hydrogen

The sugars found in nucleic acids consists of

5 carbons

The components of fats are long chain acids and

Glycerol

Water soluble (hydrophilic) compounds freely pass through the membranes of bacteria.

False

Amino acids in proteins are linked to one another by peptide bonds between the

terminal carboxyl group of one amino acid and the terminal amino group of another amino acid

The primary structure in a protein refers to the

sequence of amino acids in the polypeptide

Weak bonds are important in the _____ structure of a protein.

secondary, tertiary, and quaternary

Dehydration reactions are involved in the formation of

polypeptides and polysaccharides

Phospholipids are amphipathic molecules.

True

Helices and B sheets of amino acids form a protein's

secondary structure

The magnifying lenses found in a compound light microscope are the

objective lens and ocular lens

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set