Question 1

Which of the following describes the correct pathway used by eukaryotic cells for the synthesis of proteins transported out of the cell?&#10;A) endoplasmic reticulum &#187; ribosomes &#187; Golgi apparatus &#187; plasma membrane&#10;B) plasma membrane &#187; ribosomes; Golgi apparatus &#187; endoplasmic reticulum&#10;C) Golgi apparatus; ribosomes &#187; endoplasmic reticulum &#187; plasma membrane&#10;D) ribosomes &#187; endoplasmic reticulum &#187; Golgi apparatus &#187; plasma membrane

Accepted Answer

The correct pathway for the synthesis of proteins transported out of the cell in eukaryotic cells is ribosomes → endoplasmic reticulum → Golgi apparatus → plasma membrane. Choice D is the only option that presents this pathway in the correct sequence. Choice A is incorrect because the Golgi apparatus should come after the ribosomes and before the plasma membrane. Choice B is incorrect because the endoplasmic reticulum should come before the Golgi apparatus. Choice C is also incorrect because the Golgi apparatus should come after the ribosomes and before the endoplasmic reticulum.

Question 2

Membrane phospholipids:&#10;A) are highly hydrophobic.&#10;B) are highly hydrophilic.&#10;C) have hydrophobic phosphate heads and hydrophilic fatty acid tails.&#10;D) have hydrophilic phosphate heads and hydrophobic fatty acid tails.&#10;E) are found in prokaryotic, but not eukaryotic, cells.

Accepted Answer

Membrane phospholipids have hydrophilic phosphate heads and hydrophobic fatty acid tails, which allows them to form a bilayer in aqueous environments. This arrangement is essential for the formation and function of cellular membranes in both prokaryotic and eukaryotic cells.

Question 3

________ bacteria lose their crystal violet when the decolorizer alcohol is added during the Gram stain procedure.&#10;A) Gram-negative&#10;B) Gram-positive&#10;C) Acid-fast&#10;D) Both Gram-negative and Gram-positive

Accepted Answer

Gram-negative bacteria have a thinner layer of peptidoglycan in their cell walls compared to Gram-positive bacteria. This makes them more susceptible to the decolorizer alcohol in the Gram stain procedure, causing them to lose their crystal violet stain and appear red or pink under the counterstain. Gram-positive bacteria, on the other hand, have a thicker layer of peptidoglycan in their cell walls which makes them more resistant to the decolorizer alcohol and retain the crystal violet stain, appearing purple under the microscope. Acid-fast bacteria have a unique cell wall structure and require a special staining method that involves heat and acid to retain their stain, which is different from the Gram stain procedure.

Question 4

Which of the following extracellular structures allows some bacteria to resist phagocytosis by phagocytic cells?&#10;A) capsule&#10;B) fimbriae&#10;C) sex pili&#10;D) flagella

Accepted Answer

The capsule is an extracellular structure that can prevent phagocytic cells from engulfing bacteria by blocking their access to the bacterial cell surface.

Question 5

What is taxis as it applies to bacteria? What structure does bacteria that are capable of taxis possess?

Accepted Answer

The answer of What is taxis as it applies to...

Question 6

Which of the following is released by dying Gram-negative bacteria, whereupon it acts as endotoxin?&#10;A) peptidoglycan&#10;B) O-polysaccharides&#10;C) porin proteins&#10;D) pentaglycine&#10;E) lipopolysacharides

Accepted Answer

Lipopolysaccharides (LPS) are components of the outer membrane of Gram-negative bacteria. When these bacteria die, their LPS is released and acts as an endotoxin, triggering an immune response in the host organism. Peptidoglycan, porin proteins, and pentaglycine are components of the bacterial cell wall, but they are not released specifically by dying Gram-negative bacteria and do not act as endotoxins. O-polysaccharides are components of the LPS molecule, but they do not specifically act as endotoxins when released by dying Gram-negative bacteria.

Question 7

________ is/are composed of long, slender protein filaments and act(s) as a type of scaffolding for eukaryotic cells.&#10;A) The cilia&#10;B) The cytoskeleton&#10;C) The endoplasmic reticulum&#10;D) The endomembrane system&#10;E) The endospore

Accepted Answer

The cytoskeleton of eukaryotic cells is composed of long, slender protein filaments, such as microtubules and microfilaments, that provide structure and support for the cell.

Question 8

Which of the following organelles found in eukaryotic cells is most likely to have been acquired by endosymbiosis?&#10;A) the nucleus&#10;B) the smooth endoplasmic reticulum&#10;C) the Golgi apparatus&#10;D) the lysosome&#10;E) the mitochondrion

Accepted Answer

The mitochondrion is the organelle most likely acquired by endosymbiosis, as it has its own DNA and ribosomes and is thought to have originated from a free-living prokaryotic organism that was engulfed by an ancestral eukaryotic cell. The other organelles listed are not thought to have been acquired through endosymbiosis.

Question 9

Bacteria which have a spherical shape are called ________.&#10;A) bacilli&#10;B) spirochetes&#10;C) vibrio&#10;D) spirilla&#10;E) cocci

Accepted Answer

Cocci are bacteria that have a spherical shape, while bacilli have a rod-like shape, spirochetes have a spiral shape, vibrio have a curved, comma-like shape, and spirilla have a corkscrew shape.

Question 10

As cells increase in size:&#10;A) their surface/volume ratio increases, and they become more metabolically efficient.&#10;B) their surface/volume ratio decreases, and they become more metabolically efficient.&#10;C) their surface/volume ratio increases, and they become less metabolically efficient.&#10;D) their surface/volume ratio decreases, and they become less metabolically efficient.

Accepted Answer

As cells increase in size, their volume increases at a faster rate than their surface area, resulting in a decreased surface/volume ratio. This means that there is less surface area available for essential processes such as gas and nutrient exchange, making the cell less metabolically efficient.

Question 11

Provide a basic description of the fluid mosaic model of membrane structure.

Accepted Answer

The answer of Provide a basic description of the fluid...

Question 12

Why is peptidoglycan such an attractive target for antibiotic drugs?

Accepted Answer

The answer of Why is peptidoglycan such an attractive target...

Question 13

Penicillin:&#10;A) prevents the linkage between N-acetyl-glucosamine and N-acetylmuramic acid.&#10;B) breaks the bonds between N-acetyl-glucosamine and N-acetylmuramic acid.&#10;C) prevents the formation of pentaglycine bridges.&#10;D) breaks pentaglycine bridges.&#10;E) perforates the plasma membrane of Gram-positive bacteria.

Accepted Answer

The answer of Penicillin:&#10;A) prevents the linkage between N-acetyl-glucosamine and...

Deck 3: The Cell: Where Life Begins