Question 1

Which of the following best explains why RNA is hypothesized to have preceded DNA in the origin of the first cells?

Accepted Answer

RNA can act as both a genetic material and a catalyst for its own replication.

Question 2

Which property is shared by all cells, regardless of domain?

Accepted Answer

Presence of a plasma membrane

Question 3

A scientist is studying a cell that contains circular DNA, ribosomes, and a double membrane. According to the endosymbiont theory, this cell structure most likely originated from:

Accepted Answer

Ancestral aerobic bacteria

Question 4

Which of the following equations correctly represents the surface area to volume ratio for a cube-shaped cell with side length $l$?

Accepted Answer

$\frac{6l^2}{l^3}$

Question 5

Why are eukaryotic cells generally larger than prokaryotic cells?

Accepted Answer

They compartmentalize materials within membrane-bounded organelles, compensating for lower surface area/volume ratio.

Question 6

Which of the following is NOT a function of the cytoskeleton in eukaryotic cells?

Accepted Answer

Synthesis of ATP

Question 7

A mutation causes the nuclear envelope of a eukaryotic cell to lose its pores. Which process would be most directly affected?

Accepted Answer

Exchange of macromolecules between the nucleus and cytoplasm

Question 8

Which organelle is responsible for the synthesis of secretory and membrane proteins, and is often studded with ribosomes?

Accepted Answer

Rough endoplasmic reticulum

Question 9

Which of the following statements about mitochondria and chloroplasts supports the endosymbiont theory?

Accepted Answer

Both contain their own circular DNA and ribosomes.

Question 10

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

Accepted Answer

They contain hydrolytic enzymes for cellular digestion.

Question 11

A plant cell is observed to have a large number of glyoxysomes. What is the most likely function of these organelles?

Accepted Answer

Converting stored fat into carbohydrate during seed germination

Question 12

Which of the following is a key difference between viruses and living cells?

Accepted Answer

Viruses do not satisfy the basic criteria of living things, such as independent metabolism.

Question 13

Which of the following best explains why plant cells can be larger than animal cells without losing efficiency in material exchange?

Accepted Answer

They compartmentalize materials within organelles and have a large central vacuole.

Question 14

Which of the following is true regarding the function of peroxisomes?

Accepted Answer

They generate and degrade hydrogen peroxide.

Question 15

A cell is observed to lack a rigid cell wall but is surrounded by an extracellular matrix. This cell is most likely:

Accepted Answer

An animal cell

Question 16

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

Accepted Answer

It modifies, packages, and sorts proteins and lipids for delivery.

Question 17

Viroids differ from viruses in that viroids:

Accepted Answer

Are small RNA molecules that do not encode proteins.

Question 18

Which of the following is a function of the extracellular matrix in animal cells?

Accepted Answer

Providing support and facilitating communication between adjacent cells

Question 19

Which of the following best explains why prions are considered infectious agents?

Accepted Answer

They are misfolded proteins that induce other proteins to misfold.

Question 20

A cell biologist is comparing ribosomes in mitochondria, chloroplasts, and bacteria. Which observation would best support the endosymbiont theory?

Accepted Answer

Mitochondrial and chloroplast ribosomes are more similar to bacterial ribosomes than to cytoplasmic ribosomes of eukaryotes.

Chapter 4: Cells and Organelles – Structure, Function, and Invading Agents

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