Question 1

Which of the following statements best distinguishes prokaryotic (bacterial) cells from eukaryotic cells?

Accepted Answer

Prokaryotic cells lack membrane-bound organelles, whereas eukaryotic cells possess them.

Question 2

A scientist discovers a cell with the following features: cytoplasm, ribosomes, a cytoskeleton, and no membrane-bound organelles. Which type of cell is this most likely to be?

Accepted Answer

A bacterial cell

Question 3

Which of the following best describes the function of ribosomes in both prokaryotic and eukaryotic cells?

Accepted Answer

They are responsible for protein synthesis using RNA and protein components.

Question 4

Which protein is specifically mentioned as being involved in the bacterial cytoskeleton and cell division?

Accepted Answer

FtsZ

Question 5

A mutation prevents the formation of the nuclear envelope in a eukaryotic cell. Which of the following processes would be most directly affected?

Accepted Answer

Physical separation of the nuclear genome from the cytoplasm

Question 6

After transcription of a gene in the nucleus, what is the next step in the process of protein synthesis in a eukaryotic cell?

Accepted Answer

The mRNA is translated by ribosomes in the cytoplasm or on the rough ER.

Question 7

Which of the following best describes the role of the signal recognition particle (SRP) during protein synthesis?

Accepted Answer

It directs the ribosome to the endoplasmic reticulum by recognizing the ER signal sequence.

Question 8

A protein destined for secretion from a eukaryotic cell will most likely follow which pathway?

Accepted Answer

Rough ER → Golgi apparatus → Vesicle → Plasma membrane

Question 9

Which of the following modifications can occur to proteins as they pass through the Golgi apparatus?

Accepted Answer

Addition of sugars (glycosylation)

Question 10

Vesicles play a critical role in the endomembrane system. Which of the following best describes their function?

Accepted Answer

They transport molecules between organelles such as the ER, Golgi, and plasma membrane.

Question 11

During insulin synthesis, which of the following steps occurs first?

Accepted Answer

Translation of preproinsulin on ribosomes associated with the rough ER

Question 12

A researcher observes that a protein is not being properly secreted from a cell. Which defect is most likely responsible?

Accepted Answer

A mutation in the ER signal sequence prevents SRP binding.

Question 13

Which of the following best explains why vesicles can fuse with different organelles within the endomembrane system?

Accepted Answer

Vesicles have specific membrane proteins that recognize and bind to target organelles.

Question 14

Which of the following is NOT a function of the Golgi apparatus?

Accepted Answer

Synthesizing ribosomal RNA

Question 15

A protein is synthesized with a 20-30 amino acid ER signal sequence. What is the fate of this sequence during protein targeting?

Accepted Answer

It is recognized by the SRP and then cleaved off in the ER lumen.

Question 16

Which of the following best describes exocytosis in the context of insulin secretion?

Accepted Answer

Fusion of a vesicle containing insulin with the plasma membrane, releasing insulin outside the cell.

Question 17

If a cell's vesicles are unable to fuse with the plasma membrane, which process would be most directly impaired?

Accepted Answer

Exocytosis of proteins such as insulin

Question 18

Which of the following equations best represents the process of protein synthesis from DNA to protein in a eukaryotic cell?

Accepted Answer

$$ DNA \xrightarrow{transcription} mRNA \xrightarrow{translation} Protein $$

Question 19

A patient has a genetic disorder that prevents the addition of sugars to proteins in the Golgi apparatus. Which cellular process is most likely to be affected?

Accepted Answer

Glycosylation of secreted proteins

Question 20

Which of the following best explains why bacterial cells can rapidly adapt to environmental changes compared to eukaryotic cells?

Accepted Answer

They lack membrane-bound organelles, allowing for faster molecular diffusion and response.

Cell Structure and the Endomembrane System

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