$\text{DNA} \xrightarrow{\text{transcription}} \text{RNA} \xrightarrow{\text{translation}} \text{Protein}$

Question 1

Which of the following statements best summarizes the cell theory as postulated by Schwann and later modified by Virchow?

Accepted Answer

All living organisms are composed of one or more cells, and all cells arise only from preexisting cells.

Question 2

Which microscopy technique would be most appropriate for observing the dynamic movement of organelles in a living cell without staining?

Accepted Answer

Phase-contrast microscopy

Question 3

A scientist wants to separate cellular organelles based on their size and density. Which method should they use?

Accepted Answer

Subcellular fractionation using centrifugation

Question 4

Which of the following units would be most appropriate for measuring the diameter of a ribosome?

Accepted Answer

Nanometer ($1 \mathrm{nm} = 10^{-9} \mathrm{m}$)

Question 5

Which discovery provided the first evidence that biological molecules obey the laws of chemistry and physics?

Accepted Answer

Friedrich Wöhler’s synthesis of urea in the laboratory

Question 6

A researcher uses an electrical field to separate DNA fragments by size. Which technique are they using?

Accepted Answer

Electrophoresis

Question 7

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

$	ext{DNA} \xrightarrow{	ext{transcription}} 	ext{RNA} \xrightarrow{	ext{translation}} 	ext{Protein}$

Question 8

Which of the following is NOT a reason why proteins were originally thought to be the genetic material instead of DNA?

Accepted Answer

DNA was known to catalyze biological reactions.

Question 9

Which of the following statements about model organisms is correct?

Accepted Answer

Model organisms are well-studied, easy to manipulate, and provide insights applicable to other species.

Question 10

A scientist is designing an experiment to test a new hypothesis about enzyme activity. Which of the following best describes a controlled experiment?

Accepted Answer

Only one variable (the independent variable) is changed, while all others are kept constant.

Question 11

Which of the following best explains why facts in science are considered provisional?

Accepted Answer

Scientific facts are based on current evidence and may change with new discoveries.

Question 12

Which of the following is a real-world application of recombinant DNA technology?

Accepted Answer

Producing insulin for diabetic patients using genetically engineered bacteria

Question 13

Which of the following statements about the use of light and electron microscopes is correct?

Accepted Answer

Electron microscopes have a much higher resolving power than light microscopes, allowing visualization of much smaller structures.

Question 14

Which of the following is an exception to the central dogma of molecular biology?

Accepted Answer

Viruses with RNA genomes that use reverse transcriptase to synthesize DNA

Question 15

A scientist wants to determine the sequence of all the genes in a newly discovered bacterium. Which field of study does this research belong to?

Accepted Answer

Genomics

Question 16

Which of the following best describes the function of tRNA during protein synthesis?

Accepted Answer

tRNA brings the appropriate amino acid to the ribosome during translation.

Question 17

Which of the following best describes the role of mass spectrometry in cell biology?

Accepted Answer

It is used to determine the size and composition of individual proteins.

Question 18

Which of the following statements about the scientific method is correct?

Accepted Answer

A hypothesis is a tentative explanation that can be tested experimentally.

Question 19

Which of the following best describes the difference between in vivo and in vitro experiments?

Accepted Answer

In vivo experiments are conducted in living organisms, while in vitro experiments are conducted outside living organisms.

Question 20

Which of the following is a key advantage of using confocal microscopy in cell biology?

Accepted Answer

It allows visualization of a single plane of a fluorescently labeled specimen, improving resolution in thick samples.

Chapter 1: A Preview of Cell Biology – Foundations, Methods, and the Flow of Genetic Information

Study Guide - Practice Questions