MCB2010 Adele Quiz 4 <3

first quiz <3

Which of the following statements is INCORRECT regarding prokaryotic cells?

-Their DNA is not enclosed within a membrane.

-They lack a plasma membrane.

-They reproduce by binary fission.

-They lack membrane-enclosed organelles.

-They typically have a circular chromosome.

They lack a plasma membrane

Each of the following statements concerning the gram-positive cell wall is true EXCEPT

-it maintains the shape of the cell.

-it is sensitive to penicillin.

-it contains teichoic acids.

-it protects the cell in a hypertonic environment.

-it is sensitive to lysozyme.

it protects the cell in a hypertonic environment.

Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5% NaCl?

Water will move out of the cell.

A gram-positive bacterium suddenly acquires resistance to the antibiotic methicillin. This trait most likely occurred due to acquisition of new genetic information through

conjugation.

By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration?

active transport

Which of the following is NOT a typical characteristic of most bacterial plasma membranes?

-composed of a phospholipid bilayer

-is selectively permeable

-contains cholesterol

-site of energy production

-contains proteins

contains cholesterol

Which one of the following organisms has a cell wall?

fungi

Which drawing in Figure 4.1 is a tetrad?

b

Which drawing in Figure 4.1 possesses an axial filament?

a

Which drawing in Figure 4.1 is streptococci?

d

Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of

osmotic lysis.

Bacteria are a commonly used organism for studies of genetic material in the research laboratory. The nucleic acids must first be isolated from the cells for these studies. Which of the following would most likely be used to remove the cell wall from gram-positive bacterial cells prior to their lysis for nucleic acid isolation?

lysozyme

Which of the following statements about gram-negative cell walls is FALSE?

-They are sensitive to penicillin.

-They are toxic to humans.

-Their Gram reaction is due to the outer membrane.

-They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids.

-They protect the cell in a hypotonic environment.

They are sensitive to penicillin.

Which of the following structures is NOT found in some prokaryotic cells?

-cilium

-flagellum

-peritrichous flagella

-pilus

-axial filament

cilium

Functions of the glycocalyx include all of the following EXCEPT

-biofilm formation.

-binary fission.

-increased virulence.

-protection against dehydration.

-source of nutrition.

binary fission.

Which structure protects bacteria from being phagocytized?

capsule

Which of the following is NOT part of the passive transport process?

ATP

Which of the following terms best describes the cell in Figure 4.2?

lophotrichous flagella

In bacteria, photosynthetic pigments are found in

chromatophores.

The difference between simple diffusion and facilitated diffusion is that facilitated diffusion

requires transporter proteins.

The terms "run" and "tumble" are generally associated with

taxic movements of the cell in response to attractants or repellents.

You have isolated a motile, gram-positive cell with no visible nucleus. You can safely assume that the cell

Has a cell wall

Fimbriae and pili differ in that

pili are used for transfer of DNA and motility.

In Figure 4.3, which diagram of a cell wall is a gram-negative cell wall?

b

In Figure 4.3, which diagram of a cell wall possesses lipid A/endotoxin responsible for symptoms associated with infection?

b

In Figure 4.3, which diagram of a cell wall has a structure that protects against osmotic lysis?

both a and b In Figure 4.3

In Figure 4.3, which diagram of a cell wall is resistant to many antibiotics (e.g., penicillin)?

b

In Figure 4.3, which diagram of a cell wall contains teichoic acids?

A

In Figure 4.3, which diagram of a cell wall contains porins?

b

Where are phospholipids most likely found in a prokaryotic cell?

the plasma membrane

Where are phospholipids most likely found in a eukaryotic cell?

the plasma membrane and organelles

Which of the following is NOT found or observed to occur in both mitochondria and prokaryotes?

cell wall

Which of the following statements is correct about passive diffusion?

It is a process in which molecules move from a region of higher concentration to a region of lower concentration (or down a concentration gradient).

Oxygen crosses a plasma membrane

through simple diffusion.

In a hypertonic solution, a bacterial cell will typically

plasmolyze.

What will happen if a bacterial cell is pretreated with a lysozyme solution, then placed in distilled water?

The cell will undergo osmotic lysis.

How do spirochetes and spirilla differ?

Spirilla have external flagella but spirochetes have axial filaments.

Which one of the following pairs is mismatched?

-ribosomes - carbon storage

-lipid inclusions - energy reserve

-sulfur granules - energy reserve

-metachromatic granules - phosphate storage

-gas vacuoles - flotation

ribosomes - carbon storage

Which of the following are NOT energy reserves?

carboxysomes

Which of the following is NOT a functionally analogous pair?

-9+2 flagella - bacterial flagella

-chloroplasts - thylakoids

-nucleus -nucleoid region

-mitochondria - prokaryotic plasma membrane

-cilia - pili

cilia - pili

The DNA found in most bacterial cells

is circular in structure

Cells may frequently find themselves in an environment with very low extracellular concentrations of substances needed in higher amounts inside the cell. To obtain these needed items, such cells would be most likely to engage in

active transport.

What is the best reason why oxygen (O2) can cross the plasma membrane by simple diffusion, but glucose must be transported across the barrier by facilitated diffusion?

Oxygen is a much smaller molecule, making it easier to pass through the molecules of the plasma membrane.

In bacterial ribosomes, a small 30S subunit and a large 50S subunit come together to produce the functional 70S ribosome. Why isn't it an 80S ribosome?

S stands for Svedberg units, which indicates the relative rate of sedimentation due to size, weight, and shape of a particle. The numbers aren't strictly additive.

A particular type of inclusion body that is used to orient bacteria in three-dimensional space in a fluid environment is the

gas vacuole.

Endospores are highly resistant to harsh environmental conditions due to all EXCEPT which one of the following?

-dipicolinic acid (DPA) in the endospore

-a thick spore coat

-small triggering molecules called germinants

-high concentration of calcium ions

-very low amounts of water

small triggering molecules called germinants