Question 1

The ratio of _____ is 1:1.

Accepted Answer

A) guanine to adenine 
B) adenine to thymine 
C) cytosine to adenine 
D) uracil to cytosine

Question 2

The molecule of heredity is

Accepted Answer

A) RNA. 
B) DNA. 
C) protein. 
D) carbohydrate. 
E) None of the choices is correct.

Question 3

How many replication forks depart from an origin of replication?

Accepted Answer

A) one 
B) two 
C) three 
D) four

Question 4

_______ -form DNA spirals to the right and is the major form of naturally occurring DNA molecules.

Accepted Answer

A) A 
B) B 
C) D 
D) Y 
E) Z

Question 5

The step in DNA replication in which two replication forks moving in opposite directions may meet is called

Accepted Answer

A) initiation. 
B) elongation. 
C) termination. 
D) translation. 
E) translocation.

Question 6

DNA replication occurs through a _________process.

Accepted Answer

A) conservative 
B) semiconservative 
C) dispersive 
D) transformative

Question 7

________ bonds are responsible for the chemical affinity between A and T (or G and C) nucleotides.

Accepted Answer

A) Ionic 
B) Covalent 
C) Hydrogen 
D) Hydrophobic

Question 8

Which of the following is not involved in ensuring the accuracy of a cell's genetic information?

Accepted Answer

A) redundancy 
B) repair enzymes 
C) precision of replication machinery 
D) DNA polymerase proofreading mechanism 
E) restriction endonucleases

Question 9

Which term describes the ability of a substance to change the genetic characteristics of an organism?

Accepted Answer

A) Transcription 
B) Translation 
C) Transformation 
D) Transposition

Question 10

The protein that progressively unwinds DNA ahead of each replication fork is called

Accepted Answer

A) primase. 
B) helicase. 
C) topoisomerase. 
D) telomerase. 
E) ligase.

Question 11

The nucleotide that is present in RNA but not DNA is

Accepted Answer

A) thymine. 
B) uracil. 
C) adenine. 
D) cytosine. 
E) guanine.

Question 12

DNA is localized mainly in the

Accepted Answer

A) cell membrane. 
B) endoplasmic reticulum. 
C) vacuoles. 
D) chromosomes.

Question 13

Which of the following properties of RNA is most directly responsible for its ability to form complex shapes?

Accepted Answer

A) The presence of uracil instead of thymine 
B) The fact that RNA is primarily double-stranded 
C) The relative instability of RNA compared to DNA 
D) The fact that RNA is primarily single-stranded 
E) The substitution of deoxyribose in DNA with ribose in RNA

Question 14

How many origins of replication does the E.coli chromosome contain?

Accepted Answer

A) None 
B) 1 
C) 2 
D) Several 
E) Many

Exam 6: DNA Structure, Replication, and Recombination