Question 1

Frederick Griffith's experiment demonstrated the concept of 'transformation' in bacteria. What was the key finding of his experiment?

Accepted Answer

Heat-killed virulent bacteria can transfer genetic material to non-virulent bacteria, making them virulent.

Question 2

In the Hershey and Chase experiment, what evidence supported DNA as the genetic material?

Accepted Answer

Radioactive phosphorus was found inside the bacterial cells, indicating DNA entered the cells.

Question 3

What was the main conclusion from Oswald Avery's experiment regarding the 'transforming principle'?

Accepted Answer

DNA is the substance responsible for transformation in bacteria.

Question 4

Which scientists are credited with discovering the double helix structure of DNA, and what technique did they use?

Accepted Answer

Watson and Crick; X-ray crystallography

Question 5

What does it mean that the strands of DNA are 'antiparallel'?

Accepted Answer

One strand runs 5' to 3' and the other runs 3' to 5'.

Question 6

During DNA replication, which enzyme is responsible for unwinding the DNA double helix?

Accepted Answer

Helicase

Question 7

The Meselson-Stahl experiment provided evidence for which model of DNA replication?

Accepted Answer

Semi-conservative

Question 8

Which enzyme joins Okazaki fragments during DNA replication?

Accepted Answer

Ligase

Question 9

What is the function of telomerase in eukaryotic cells?

Accepted Answer

It adds repetitive nucleotide sequences to the ends of chromosomes to prevent shortening.

Question 10

Which of the following best describes the difference between the leading and lagging strands during DNA replication?

Accepted Answer

The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments called Okazaki fragments.

Question 11

Which enzyme synthesizes RNA primers during DNA replication?

Accepted Answer

Primase

Question 12

A mutation in the gene encoding DNA polymerase results in frequent errors during DNA replication. What is the most likely consequence?

Accepted Answer

Higher mutation rates in daughter cells

Question 13

Which of the following best explains why DNA replication is described as 'semi-conservative'?

Accepted Answer

Each new DNA molecule contains one parental strand and one newly synthesized strand.

Question 14

Which enzyme relieves the tension caused by unwinding of the DNA helix during replication?

Accepted Answer

Topoisomerase

Question 15

If a cell lacks functional DNA ligase, what would be the most immediate effect during DNA replication?

Accepted Answer

Okazaki fragments on the lagging strand would not be joined together.

Question 16

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

Accepted Answer

Synthesizing proteins directly

Question 17

What is the role of histones in chromatin structure?

Accepted Answer

They help package DNA into nucleosomes, aiding in compaction and regulation.

Question 18

Which of the following best describes heterochromatin?

Accepted Answer

It is tightly packed and generally transcriptionally inactive.

Question 19

A scientist observes that a cell has abnormally short telomeres. What is a likely consequence for this cell?

Accepted Answer

The cell may undergo senescence or apoptosis due to loss of chromosome protection.

Question 20

Which of the following equations correctly represents the complementary base pairing in DNA?

Accepted Answer

$$A = T$$ and $$G = C$$

Chapter 16: DNA Structure, Replication, and Chromosomal Organization – Study Guide

Study Guide - Practice Questions