Question

1. Chain terminators block further DNA synthesis because they are missing which of the following?

Group of answer choices

A. 3' OH

B. 5' phosphate

C. A fluorescent dye

2.The cycle sequencing reaction generates:

Group of answer choices

A. Fragments of the same size; because the chain terminator integration site is the same in each newly synthesized fragment

B. Fragments of the same size; because the chain terminator integration site can be different in each newly synthesized fragment

C. Fragments of different sizes; because the chain terminator integration site can be different in each newly synthesized fragment

D. Fragments of different sizes; because the chain terminator integration site is the same in each newly synthesized fragment

3. Each fragment generated during the cycle sequence reaction is labeled with:

Group of answer choices

A. All four colors of fluorescent dye throughout the length of the fragment

B. All four colors of fluorescent dyes at one end of the fragment

C. One color of fluorescent dye at one end of the fragment

D. One color of fluorescent dye throughout the length of the fragment

4. What is the purpose of the ethanol precipitation step when preparing your samples for automated Sanger Sequencing?

Group of answer choices

A. Purification of the cycle sequencing products

B. Enzymatic digestion of the cycle sequencing products

C. Ligation of the cycle sequencing products into a plasmid

D. Dye attachment to the cycle sequencing products

5. Capillary electrophoresis separates the fragments out by size in order to send them through the sequencer to be read one by one, each different in length by a single nucleotide! Which do you predict the sequencer will detect (aka read) first? In other words, which will travel through the capillary the fastest?

(Similar to agarose gel electrophoresis!)

Group of answer choices

A. Longest fragment

B. Shortest fragment

6. We are not interested in all of the sequencing information we will obtain through this method. Which resulting sequence information do you want to analyze to address your research question as designed in the lab this semester?

Group of answer choices

A. Insert sequence that corresponds to the yellow gene non-coding region

B. Insert sequence that corresponds to the yellow gene coding region

C. TOPO vector sequence

Answer 1

Answer 1:

DNA polymerase enzyme can add nucleotide only if it has a 3' OH group. If a nucleotide lacks a 3'OH group, then it cannot be added by the enzyme, and such a nucleotide acts as a chain terminator. Hence, the correct choice should be:

(A) 3' OH.

Answer 2:

During the cycle sequencing, fragments are of different sizes. This is because of change in the position of chain terminator site. The correct choice should be:

(C) Fragments of different sizes; because the chain terminator integration site can be different in each newly synthesized fragments.