Question 1

DNA is isolated from a virus and found to contain 27% A, 27% T, 23% C and 23% G. The DNA is likely to be:

Accepted Answer

A) contaminated with RNA. 
B) circular. 
C) single stranded. 
D) double stranded.

Question 2

Which of the following mRNA modifications is common in human cells?

Accepted Answer

A) 5' cap addition 
B) intron removal and exon joining 
C) 3' poly-A tail addition 
D) alternative splicing 
E) All of these choices are correct.

Question 3

Which of the following is TRUE of DNA?

Accepted Answer

A) Successive nucleotides in a strand are connected by hydrogen bonds. 
B) A phosphate group in a nucleotide is attached to the 3F1F1F1S1F1F1F10 carbon in ribose. 
C) A purine always forms a complementary base pair with a pyrimidine. 
D) The percentage of the purine A always equals the percentage of the purine G. 
E) It is used by ribosomes for translation.

Question 4

Transcription starts at a _____ and ends at a _____.

Accepted Answer

A) promoter; terminator 
B) 5' cap; terminator 
C) promoter; 5' end 
D) 3' end; 5' end

Question 5

In a deoxyribonucleotide, what chemical group is found at the 2' carbon of the sugar component?

Accepted Answer

A) an oxygen 
B) a hydroxyl group 
C) one or more phosphate groups 
D) an amino group 
E) a hydrogen

Question 6

In an RNA world:

Accepted Answer

A) RNA functions for information storage and proteins do catalysis. 
B) DNA functions for information storage and RNA does catalysis. 
C) RNA functions for information storage and for catalysis. 
D) RNA functions for information storage and there is no catalysis. 
E) None of the other answer options is correct.

Question 7

In an RNA world:

Accepted Answer

A) RNA functions in information storage and proteins do catalysis. 
B) DNA functions in information storage and RNA alone catalyzes reactions. 
C) RNA functions in information storage and for catalysis. 
D) RNA functions in information storage and there is no catalysis. 
E) None of the other answer options is correct.

Question 8

RNA processing occurs in:

Accepted Answer

A) prokaryotes only. 
B) eukaryotes only. 
C) viruses only. 
D) both prokaryotes and eukaryotes. 
E) both prokaryotes and viruses.

Question 9

In double-stranded DNA, the sugar-phosphate backbones are:

Accepted Answer

A) on the outside, separated by grooves of equal size. 
B) on the outside, separated by grooves of unequal size. 
C) on the inside, separated by grooves of equal size. 
D) on the inside, separated by grooves of unequal size.

Question 10

Which one of the following statements about RNA is INCORRECT?

Accepted Answer

A) The nucleotide at the 5' end of an RNA molecule is typically a nucleoside triphosphate. 
B) RNA is usually found in double-stranded form, just like DNA. 
C) RNA molecules are typically shorter than DNA molecules. 
D) RNA molecules can form base pairs within a single strand. 
E) RNA molecules are capable of evolving their enzymatic activity over time.

Question 11

The complementary base pairing of nucleotides in a DNA molecule is a structural feature that has important implications for DNA's function. What is the structural relationship between purine and pyrimidine nucleotides?

Accepted Answer

The answer of The complementary base pairing of nucleotides in...

Question 12

RNA polymerase complex can do which of the following?

Accepted Answer

A) allow RNA-DNA hybrids to form 
B) release a finished RNA transcript from a DNA template 
C) separate DNA strands 
D) restore the original DNA strands 
E) All of these choices are correct.

Question 13

In a long double-stranded DNA molecule containing the genetic information for many genes, the template strand for one gene may be the nontemplate strand for another gene along the way.

Accepted Answer

A) True 
 B)False

Question 14

In order to test the effects of a new drug, you isolate the messenger RNA molecules from both treated and untreated eukaryotic cells and separate them according to size using gel electrophoresis. In each lane of the gel, the shorter RNA molecules migrate more quickly through the gel and end up near the bottom of the gel while the longer RNAs migrate more slowly and remain near the top.  The samples that were loaded into each of the four lanes are as follows:
Lane 1: the primary RNA transcripts isolated from the nucleus of untreated cells
Lane 2: the primary RNA transcripts isolated from the nucleus of cells treated with the drug being tested
Lane 3: RNA isolated from the cytosol of untreated cells
Lane 4: RNA isolated from the cytosol of cells treated with the drug being tested
Based on the information provided by the gel shown above, what cellular process appears to be affected by the new drug?

Accepted Answer

The answer of In order to test the effects of...

Question 15

In order for a nucleotide to be added to a growing RNA strand, the polymerase ensures that hydrogen bonds between the incoming base and the template strand are properly made before the high-energy phosphate bond is cleaved.

Accepted Answer

A) True 
 B)False

Question 16

DNA wraps around histone and other proteins to form _____.

Accepted Answer

The answer of DNA wraps around histone and other proteins...

Question 17

A template strand of DNA is read in the _____ direction in order to direct synthesis of RNA in the _____ direction.

Accepted Answer

A) 3'-5'; 3'-5' 
B) 5'-3'; 3'-5' 
C) 3'-5'; 5'-3' 
D) 5'-3'; 5'-3'

Question 18

The central dogma of molecular biology states that information flows from:

Accepted Answer

A) DNA directly to protein. 
B) protein to RNA to DNA. 
C) DNA to RNA to protein. 
D) RNA to protein to DNA. 
E) RNA to DNA to protein.

Question 19

Supercoils in DNA are induced or relaxed by enzymes called topoisomerases.

Accepted Answer

A) True 
 B)False

Question 20

In transcription, each added ribonucleotide comes into the RNA polymerase complex as a:

Accepted Answer

A) nucleoside. 
B) nucleoside monophosphate. 
C) nucleoside diphosphate. 
D) nucleoside triphosphate.

Exam 3: Nucleic Acids and Transcription

DNA is isolated from a virus and found to contain 27% A, 27% T, 23% C and 23% G. The DNA is likely to be:

Which of the following mRNA modifications is common in human cells?

Which of the following is TRUE of DNA?

Transcription starts at a _ and ends at a _.

In a deoxyribonucleotide, what chemical group is found at the 2' carbon of the sugar component?

In an RNA world:

In an RNA world:

RNA processing occurs in:

In double-stranded DNA, the sugar-phosphate backbones are:

Which one of the following statements about RNA is INCORRECT?

The complementary base pairing of nucleotides in a DNA molecule is a structural feature that has important implications for DNA's function. What is the structural relationship between purine and pyrimidine nucleotides?

RNA polymerase complex can do which of the following?

In a long double-stranded DNA molecule containing the genetic information for many genes, the template strand for one gene may be the nontemplate strand for another gene along the way.

In order for a nucleotide to be added to a growing RNA strand, the polymerase ensures that hydrogen bonds between the incoming base and the template strand are properly made before the high-energy phosphate bond is cleaved.

DNA wraps around histone and other proteins to form _____.

A template strand of DNA is read in the _ direction in order to direct synthesis of RNA in the _ direction.

The central dogma of molecular biology states that information flows from:

Supercoils in DNA are induced or relaxed by enzymes called topoisomerases.

In transcription, each added ribonucleotide comes into the RNA polymerase complex as a: