Question 1

Which of the following best describes the main function of the rough endoplasmic reticulum (rough ER) in eukaryotic cells?

Accepted Answer

Synthesis of proteins destined for secretion or for membranes

Question 2

A cell is exposed to a toxin that inhibits the addition of carbohydrates to proteins. Which organelle's function is most directly affected?

Accepted Answer

Rough endoplasmic reticulum

Question 3

Which of the following processes is most directly associated with the smooth endoplasmic reticulum?

Accepted Answer

Lipid synthesis and detoxification

Question 4

A mutation prevents the formation of transport vesicles from the transitional ER. Which cellular process would be most immediately disrupted?

Accepted Answer

Modification of proteins in the Golgi apparatus

Question 5

Which of the following best explains why lysosomal enzymes are less active if released into the cytosol?

Accepted Answer

The cytosol has a near-neutral pH, which is not optimal for lysosomal enzymes

Question 6

A patient is diagnosed with Tay-Sachs disease, a lysosomal storage disorder. Which cellular process is most directly impaired?

Accepted Answer

Digestion of specific lipids within lysosomes

Question 7

Which of the following is a function of the central vacuole in mature plant cells?

Accepted Answer

Storage of inorganic ions and water, contributing to cell growth

Question 8

During phagocytosis, which sequence of events correctly describes the fate of an engulfed bacterium?

Accepted Answer

Bacterium is enclosed in a food vacuole, which fuses with a lysosome for digestion

Question 9

Which of the following best describes the cisternal maturation model of the Golgi apparatus?

Accepted Answer

Cisternae move from the cis to the trans face, carrying and modifying cargo

Question 10

A plant cell is observed to have a large central vacuole filled with pigments. What is the most likely function of these pigments?

Accepted Answer

To attract pollinators to the plant's flowers

Question 11

Which of the following best explains how the endomembrane system contributes to the secretion of insulin from pancreatic cells?

Accepted Answer

Insulin is synthesized in the rough ER, modified in the Golgi apparatus, and transported in vesicles to the plasma membrane for secretion

Question 12

Which of the following is a key difference between the rough ER and the smooth ER?

Accepted Answer

Rough ER has ribosomes on its surface, while smooth ER does not

Question 13

A mutation causes the Golgi apparatus to fail in adding phosphate groups to proteins. What is the most likely consequence?

Accepted Answer

Proteins will not be properly sorted and targeted to their destinations

Question 14

Which of the following equations best represents the process of hydrolysis carried out by lysosomal enzymes?

Accepted Answer

$$	ext{Macromolecule} + 	ext{H}_2	ext{O} ightarrow 	ext{Monomers}$$

Question 15

Which of the following best describes autophagy?

Accepted Answer

The recycling of the cell’s own organelles and macromolecules by lysosomes

Question 16

A unicellular protist living in freshwater uses contractile vacuoles. What is the main function of these vacuoles?

Accepted Answer

To pump excess water out of the cell and maintain osmotic balance

Question 17

Which of the following best explains why the cytosol forms a thin layer between the central vacuole and the plasma membrane in mature plant cells?

Accepted Answer

To maintain a sufficient ratio of plasma membrane surface to cytosolic volume

Question 18

Which of the following is a real-life example of phagocytosis in human cells?

Accepted Answer

Macrophages engulfing and destroying bacteria

Question 19

A scientist observes that a cell is unable to detoxify drugs and poisons efficiently. Which organelle is most likely malfunctioning?

Accepted Answer

Smooth endoplasmic reticulum

Question 20

Which of the following best describes the flow of proteins through the endomembrane system?

Accepted Answer

Nucleus → Rough ER → Golgi apparatus → Plasma membrane

The Endomembrane System: Structure and Function in Eukaryotic Cells

Study Guide - Practice Questions