Q: If a eukaryotic chromosome contains 100 replicons and each replicon is 100,000 base pairs long, what is the approximate length of the chromosome?

$$100 \times 100,000 = 10,000,000$$ base pairs

Question 1

Which of the following best describes a 'cis element' in the context of DNA replication initiation?

Accepted Answer

A DNA sequence that serves as a start site for replication

Question 2

Why are origins of replication (ori) typically rich in AT base pairs?

Accepted Answer

AT base pairs are easier to separate due to fewer hydrogen bonds

Question 3

In E. coli, which protein binds to the dnaA box to initiate DNA replication?

Accepted Answer

DnaA

Question 4

What is the role of Dam methylation in bacterial DNA replication initiation?

Accepted Answer

It is required for DnaA binding and proper initiation of replication

Question 5

Which of the following best defines a 'replicon'?

Accepted Answer

A piece of DNA controlled by a single origin of replication

Question 6

If a eukaryotic chromosome contains 100 replicons and each replicon is 100,000 base pairs long, what is the approximate length of the chromosome?

Accepted Answer

$$100 	imes 100,000 = 10,000,000$$ base pairs

Question 7

Which statement about DNA replication in eukaryotes is correct?

Accepted Answer

Replication origins are selected and activated in a coordinated manner

Question 8

What is the function of the Origin Recognition Complex (ORC) in eukaryotic cells?

Accepted Answer

It binds to the origin of replication and recruits other replication factors

Question 9

During DNA replication, what is the significance of the replication bubble?

Accepted Answer

It is the region where DNA is unwound and replication occurs

Question 10

In the Meselson-Stahl experiment, which model of DNA replication was supported by the results?

Accepted Answer

Semiconservative replication

Question 11

Which of the following is a trans-acting factor in DNA replication?

Accepted Answer

DNA polymerase

Question 12

A mutation prevents methylation of GATC sequences in E. coli. What is the most likely consequence?

Accepted Answer

DnaA will not bind efficiently, blocking replication initiation

Question 13

Which of the following best explains why eukaryotic chromosomes require multiple origins of replication?

Accepted Answer

Eukaryotic chromosomes are much larger and need multiple origins to replicate in a reasonable time

Question 14

Which of the following is true about the activation of replicons in eukaryotic cells during S phase?

Accepted Answer

Replicons near active genes are replicated earliest

Question 15

What is the main difference between bidirectional and unidirectional DNA replication?

Accepted Answer

Bidirectional replication involves two replication forks moving in opposite directions from the origin

Question 16

Which sequence is essential for the function of the yeast ARS (autonomously replicating sequence)?

Accepted Answer

The consensus sequence in the A domain

Question 17

A scientist observes that DNA replication in a cell is blocked until the next cell cycle. Which complex is most likely responsible for this regulation?

Accepted Answer

Pre-replication complex (Pre-RC)

Question 18

If a bacterial cell has a mutation that prevents ATP from being converted to ADP during replication initiation, what is the likely outcome?

Accepted Answer

Replication initiation will be blocked due to lack of ATPase activity

Question 19

Which of the following best describes the role of licensing factors in eukaryotic DNA replication?

Accepted Answer

They recruit helicase to the origins and ensure replication occurs only once per cell cycle

Question 20

A cell is observed to have 300 replication foci during S phase. What does this observation most likely indicate?

Accepted Answer

Multiple replicons are active simultaneously, each focus representing a cluster of replication origins

DNA Replication Origins and Initiation: Structure and Mechanism

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드