Question 1

A collection of cloned DNA fragments is called a .&#10;A)consortium&#10;B)chromosomal database&#10;C)chromosome library&#10;D)gene library

Accepted Answer

A collection of cloned DNA fragments is commonly referred to as a gene library or genomic library. This library contains a collection of all the DNA fragments from a particular organism that have been cloned and stored. Choices A and B do not accurately describe a collection of cloned DNA fragments, while choice C is similar to a gene library but specifically refers to a collection of entire chromosomes rather than individual genes.

Question 2

What types of genes are found on plasmids and often used as selectable markers?&#10;A)antibiotic resistance genes&#10;B)multiple cloning sites&#10;C)origins of replication&#10;D)methylated sequences

Accepted Answer

Antibiotic resistance genes are commonly found on plasmids and are often used as selectable markers because they allow researchers to easily select for cells that have taken up the plasmid by growing them in the presence of an antibiotic.

Question 3

Why must a shuttle vector possess two origins of replication instead of one?&#10;A)Shuttle vectors must replicate in multiple hosts with each host requiring a different origin.&#10;B)Shuttle vectors must be able to replicate from two different origins of replication depending upon the specific growth conditions.&#10;C)Shuttle vectors only have one origin of replication,not two.&#10;D)Shuttle vectors use one origin for replication and the other origin for shuttling recombinant DNA into new hosts.

Accepted Answer

Shuttle vectors are designed to replicate in two different host species, typically a bacterium (like E. coli) and a eukaryotic organism (like yeast). Each host species requires a compatible origin of replication, hence the need for two origins.

Question 4

Yeast artificial chromosomes must have and in order to function within eukaryotes.&#10;A)origin of replication;internal resolution sites&#10;B)telomere sequences;centromere sequences&#10;C)multiple cloning sites;genes for nuclear proteins&#10;D)multiple promoters;genes for antibiotic resistance

Accepted Answer

Yeast artificial chromosomes need telomere sequences to prevent degradation at the ends and centromere sequences to ensure proper segregation during cell division.

Question 5

The enzyme that links the ends of two DNA molecules is called .&#10;A)reverse transcriptase&#10;B)DNA polymerase&#10;C)DNA ligase&#10;D)DNA helicase

Accepted Answer

DNA ligase is the enzyme that seals the nick between the sugar-phosphate backbone of two DNA strands, which results in the formation of a phosphodiester bond. This process is essential for the replication and repair of DNA.

Question 6

Which process enables recombinant DNA to be introduced into mammalian cell lines?&#10;A)Transfection&#10;B)Transduction&#10;C)Transformation&#10;D)Translocation

Accepted Answer

Transfection is the process of introducing foreign DNA into mammalian cells. This is commonly done through the use of liposomes or other vectors, which can cross the cell membrane and deliver the DNA to the cytoplasm of the host cell. Transduction is the process of introducing foreign DNA into bacterial cells using a virus as a vector. Transformation involves the uptake of DNA from the environment by a bacterial cell, while translocation involves the movement of DNA within a chromosome.

Question 7

Which of the following cloning vectors carries the largest insert relative to the others in the answer choices?&#10;A)BACs&#10;B)cosmids&#10;C)PACs&#10;D)plasmids

Accepted Answer

BACs (Bacterial Artificial Chromosomes) carry the largest insert range, up to 300kb, which is larger than that of PACs (P1 Artificial Chromosomes), cosmids, and plasmids. Therefore, BACs are the best choice for cloning larger DNA fragments such as genomic DNA or larger gene clusters.

Question 8

Reverse transcriptase generates cDNA from a template.&#10;A)DNA&#10;B)transfer RNA&#10;C)messenger RNA&#10;D)cDNA

Accepted Answer

Reverse transcriptase is an enzyme that catalyzes the synthesis of complementary DNA (cDNA) from a single-stranded RNA template. Therefore, the correct choice is option C, messenger RNA (mRNA), as it is the RNA molecule that carries genetic information from the DNA to the ribosome, where it is translated into proteins.

Question 9

The purpose of the centromere sequence in YACs is to .&#10;A)provide a multiple cloning site&#10;B)allow correct partitioning of the plasmid in yeast&#10;C)allow the vector to replicate in the yeast&#10;D)select for the presence of the vector in the host

Accepted Answer

The centromere sequence in YACs is necessary to allow correct partitioning of the plasmid in yeast. This ensures that each daughter cell receives a copy of the plasmid during cell division. Without the centromere sequence, the plasmid may be lost during cell division. The other options listed are not relevant to the role of the centromere sequence in YACs.

Question 10

Restriction enzymes .&#10;A)generate either blunt or sticky ends by cutting the DNA on each strand.&#10;B)are nucleases.&#10;C)recognize specific sequences and cleave the DNA at the recognition site or somewhere in the vicinity.&#10;D)are all of the above.

Accepted Answer

Restriction enzymes are nucleases that recognize specific sequences and cut the DNA at the recognition site or nearby, generating either blunt or sticky ends on each strand. Therefore, option D correctly summarizes all of the essential characteristics of restriction enzymes.

Question 11

Cells methylate their own DNA to .&#10;A)mark the DNA for degradation&#10;B)prevent replication&#10;C)protect the DNA from the cell's own restriction enzymes&#10;D)stabilize the DNA double helix

Accepted Answer

The answer of Cells methylate their own DNA to .&#10;A)mark...

Deck 7: Recombinant DNA Technology