Q: A nerve cell is modeled as an elongated cell measuring $$125 \times 1 \times 1$$ arbitrary units. What is its surface area-to-volume ratio?

Surface area: $$2(125 \times 1) + 2(125 \times 1) + 2(1 \times 1) = 252$$; Volume: $$125 \times 1 \times 1 = 125$$; Ratio: $$\frac{252}{125} \approx 2.02$$

Question 1

Which of the following best explains why eukaryotic cells can compartmentalize their functions more efficiently than prokaryotic cells?

Accepted Answer

Eukaryotic cells possess internal membranes that create specialized organelles for distinct functions.

Question 2

A scientist isolates an organelle with a double membrane, its own DNA, and ribosomes. This organelle is most likely responsible for which of the following cellular processes?

Accepted Answer

ATP production through cellular respiration

Question 3

Which of the following pathways correctly traces the route of a protein destined for secretion from a eukaryotic cell, starting from the mRNA that encodes it?

Accepted Answer

mRNA → bound ribosome on rough ER → transport vesicle → Golgi apparatus → plasma membrane

Question 4

A nerve cell is modeled as an elongated cell measuring $$125 	imes 1 	imes 1$$ arbitrary units. What is its surface area-to-volume ratio?

Accepted Answer

Surface area: $$2(125 	imes 1) + 2(125 	imes 1) + 2(1 	imes 1) = 252$$; Volume: $$125 	imes 1 	imes 1 = 125$$; Ratio: $$\frac{252}{125} \approx 2.02$$

Question 5

Which of the following is NOT a function of the smooth endoplasmic reticulum (ER)?

Accepted Answer

Protein glycosylation

Question 6

A mutation prevents the formation of the nuclear lamina in a eukaryotic cell. Which of the following consequences is most likely?

Accepted Answer

The nucleus will lose mechanical support and may become misshapen.

Question 7

Which evidence supports the endosymbiont theory for the origin of mitochondria and chloroplasts?

Accepted Answer

Both organelles contain their own DNA and ribosomes, and replicate independently of the cell.

Question 8

A cell is observed to have an extensive network of rough endoplasmic reticulum. Which of the following is the most likely function of this cell?

Accepted Answer

Production of large amounts of secreted proteins

Question 9

Which of the following best describes the role of lysosomes in animal cells?

Accepted Answer

They hydrolyze macromolecules and recycle cellular components.

Question 10

A plant cell is placed in a solution that causes its central vacuole to shrink. Which of the following best explains the observed effect?

Accepted Answer

Water leaves the vacuole, causing loss of turgor pressure.

Question 11

Which of the following statements about ribosomes is correct?

Accepted Answer

Ribosomes are composed of rRNA and protein and are the site of polypeptide synthesis.

Question 12

A liver cell exposed to high levels of barbiturates is observed to have an increased amount of smooth ER. What is the most likely explanation for this observation?

Accepted Answer

The cell is increasing its capacity for detoxification of drugs.

Question 13

Which of the following best describes the function of the Golgi apparatus in the endomembrane system?

Accepted Answer

It modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Question 14

A mutation causes a defect in the transport vesicles that bud from the rough ER. Which process would be most directly affected?

Accepted Answer

Delivery of newly synthesized proteins to the Golgi apparatus

Question 15

Which of the following is a function of peroxisomes in eukaryotic cells?

Accepted Answer

Breakdown of fatty acids and detoxification of alcohol by producing hydrogen peroxide

Question 16

Which of the following best explains why mitochondria have highly folded inner membranes (cristae)?

Accepted Answer

To increase the surface area for enzymes involved in ATP production

Question 17

A cell is observed to have a large central vacuole, chloroplasts, and a cell wall. Which of the following is most likely true about this cell?

Accepted Answer

It is a plant cell capable of photosynthesis and storage.

Question 18

Which of the following best describes the relationship between the nucleus and ribosomes in a eukaryotic cell?

Accepted Answer

The nucleus contains DNA, which is transcribed into mRNA; ribosomes translate mRNA into proteins.

Question 19

Which of the following is a real-world example of the importance of the endomembrane system in human health?

Accepted Answer

Defects in lysosomal enzymes can lead to Tay-Sachs disease, a fatal genetic disorder.

Question 20

Which of the following statements about the cytoskeleton is correct?

Accepted Answer

The cytoskeleton is a dynamic network of fibers that organizes structures and activities in the cell.

A Tour of the Cell: Structure and Function of Eukaryotic Cells

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