Deck 10: DNA Sequencing

Question 1

In Maxam-Gilbert sequencing, co-migrating bands that are present in lanes from the tube treated with hydrazine (T or C) and the tube treated with hydrazine plus salt (T) are read as which of the following nucleotides?

A) A
B) T
C) C
D) G

Answer 1

T

Question 2

Cycle sequencing was made possible through the development of what reagents?

A) Fluorescent dyes
B) dITP
C) Labeled primers
D) Heat-stable polymerases

Answer 2

Heat-stable polymerases

Question 3

In bioinformatics, when a sequence is entered and compared with all other sequences in a database, which of the following is being performed?

A) Algorithm
B) Query
C) Motif
D) Annotation

Answer 3

Query

Question 4

When two sequences are found to be exactly the same, they have which of the following?

A) Heterology
B) Identity
C) Alignment
D) Motif

Question 5

The ddNTP:dNTP ratio is too high (too much ddNTP). How will this affect sequencing results?

A) No effect
B) A sequencing ladder of only short fragments
C) A sequencing ladder of only long fragments
D) Equally spaced bands in every lane

Question 6

Dye terminator sequencing has been performed using capillary electrophoresis to separate the fragments. ddATP has been labeled with a "green" fluor, ddTTP with "red," ddCTP with "blue," and ddGTP with "black." The colors are detected in the following order: red, green, black, red, green, blue, red, black, black, green, blue. What is the sequence of this fragment?

A) TCGTCATGGAC
B) GCTACGTAATG
C) CAGGTCATGAT
D) TAGTACTGGAC

Question 7

Incomplete cleaning of the fluorescently labeled sequencing ladder will result in what effect?

A) Dim bands or peaks
B) Unequal signal from lane to lane
C) Dye blobs
D) Equally spaced bands in every lane

Question 8

In Maxam-Gilbert sequencing, a band that is present in the lane from the tube treated with formic acid (G or A) but not the tube treated with dimethyl sulfate (G) is read as which of the following nucleotides?

A) A
B) T
C) C
D) G

Question 9

Which end of the sequenced DNA is found at the bottom of a sequencing gel?

A) 5
B) 3
C) 2
D) 1

Question 10

Which of the following is a genetic sequence database that is sponsored by the National Institutes of Health?

A) PubMed
B) Swiss-Prot
C) GenBank
D) Interface

Question 11

A pyrosequencer detects visible light, making it which type of instrument?

A) Luminometer
B) UV spectrotometer
C) Mass spectrometer
D) Fluorometer

Question 12

In the Sanger sequencing method, which of the following when incorporated into the growing strand are used to determine the identity of the base at a particular position in a piece of DNA?

A) ribonucleotides
B) deoxyribonucleotides
C) dideoxyribonucleotides
D) amino acids

Question 13

Which is the output from capillary electrophoresis of a fluorescent product?

A) Autoradiogram
B) Electropherogram
C) Pictogram
D) Nomogram

Question 14

A Sanger sequencing procedure has been performed on a 300-bp piece of DNA. When the fragments were resolved on the gel, there were bands distributed throughout the T, C and A lanes, but in the G lane, there was one thick band at the bottom of the gel. What is the likely cause of these results?

A) No dGTP was added to the G reaction mix.
B) No ddGTP was added to the G reaction mix.
C) There was only one G in the whole 300-bp piece of DNA.
D) The 300-bp piece of DNA contained Gs only.

Question 15

An analysis that takes place in silico is happening in which of the following places?

A) Computer
B) Laboratory
C) Biological organism
D) Tissue

Question 16

A portion of a sequencing gel is described as follows: the first band at the bottom of the gel was in the ddATP lane; the next band going up the gel was in the ddTTP lane, then the ddCTP lane, the ddGTP lane, the ddATP lane, the ddTTP lane, the ddCTP lane, the ddCTP lane, the ddATP lane, and the ddGTP lane. Which of the following is the correct sequence as determined on this gel?

A) 5GACCTAGCTA3
B) 3ATCGATCCAG5
C) 5ATCGATCCAG3
D) 3TCAGTCAGC5

Question 17

Sequencing ladders resolved by gel electrophoresis are read in which of the following directions?

A) Top to bottom
B) Bottom to top
C) Across lanes
D) Diagonally

Question 18

Which of the following is the most widely used method of DNA sequencing in clinical laboratories today?

A) Pyrosequencing
B) Maxam-Gilbert sequencing
C) Sanger sequencing
D) Array sequencing

Question 19

Which of the following are included in sequencing reactions to deter secondary structure in the template and synthesized fragments?

A) Deaza-GTP
B) Manganese
C) Magnesium
D) Extra dNTPs

Question 20

Dideoxycytidine is added to one of four sequencing reactions. All of the DNA fragments produced in that reaction end with which of the following nucleotides?

A) dG
B) ddC
C) dC
D) ddG

Question 21

The goal of the HapMap project is which of the following?

A) Find blocks of SNPs that are inherited together
B) Complete the human genome sequence
C) Compare human and primate genomes
D) Sequence all bacterial genomes

Question 22

A segment of DNA has been sequenced and noted as the following: AYKWHT. Which of the following is the correct interpretation of this notation?

A) A, T/C, G/T, A/T, A/C/T, T
B) A, G/T, A/G, C/G, G/T, A/C/T
C) A, A/C/G, A/T, C/T, T, U
D) A, A/G, C/T, A/C, G/T, C/G, T

Question 23

Ten equivalents of a genome were cut into small pieces and sequenced. Computers were then used to put the sequences of the pieces together to determine the sequence of the intact genome. The method described is which of the following?

A) Basic Local Alignment Search Tool
B) Hierarchal Genome Sequencing
C) Whole Genome Shotgun Sequencing
D) Gene Recognition and Assembly

Question 24

What part of the human genome accounts for encoded proteins?

A) 75%
B) 50%
C) 10%
D) 2%

Question 25

Which of the following pieces of information has been determined about the human genome?

A) Chromosome 13 has the most genes per bp.
B) The size of the human genome is 3 Gbp.
C) The average gene size is 45 kbp.
D) Chromosome X has the fewest genes.