Chapter 20 test

To create recombinant DNA with long-term stability, it is necessary to have which of the following in the test tube? ()

DNA ligase

Which one of the following enzymes could seal a nick in one strand of a double-stranded DNA molecule by creating a sugar-phosphate bond between the adjacent, unjoined nucleotides? ()

DNA ligase

Human nerve cells differ from human muscle cells because different sets of genes are expressed; in each type of cell, different genes are transcribed into mRNA and translated into protein. Which of the following techniques would be the most efficient way to identify the genes that these cells express? ()

DNA microarray assays

________ can give rise to any type of cell while ________ can give rise to a subset of cell types. ()

Embryonic stem cells; adult stem cells

Dolly, the sheep, was cloned from an adult cell. She had a number of health problems and died at a relatively young age. Three mules that were born in 2003 were cloned from fetal cells. If it turns out that the mules remain healthy and live normal lives, how would this outcome tie in with Gurdon's observations with tadpoles? ()

Gurdon found that the ability of a transplanted nucleus to direct normal development was inversely related to the age of the donor.

Nuclear transplantation involves _____. ()

Removing the nucleus of an egg cell and replacing it with the nucleus of a somatic cell

A molecular biologist used a retroviral vector to introduce a gene coding for a certain human enzyme into mouse cells. One cell line was isolated that was able to make the human enzyme, but it had lost the ability to express an endogenous, normally expressed gene in the process. What is the best explanation for these results? ()

The virus inserted the gene encoding the human enzyme into the normally expressed endogenous gene.

A genetic marker is _____. ()`

a particular nucleotide sequence at a particular locus whose inheritance can be followed

In recombinant methods, the term "vector" refers to _____. ()

a plasmid or other agent used to transfer DNA into a living cell

Which of the following would be considered a transgenic organism? ()

a rat with rabbit hemoglobin genes

What two enzymes are needed to produce recombinant DNA? ()

a restriction enzyme and a ligase

Southern blotting is _____. ()

a technique used to study RFLPs

Gene therapy involves _____. ()

adding a functioning version of a defective gene to the cells of an individual

A scientist wishing to create an organism capable of breaking down several kinds of toxic waste combines genes from several species of bacteria to create a single "superbacterium." Which of the following would be needed to do this? ()

all of the above

Separating DNA fragments by gel electrophoresis is useful for which of the following? ()

all of the above

DNA synthesized using an RNA template is called _____. ()

cDNA

The efficiency of cloning, and the ability to generate healthy cloned animals, has been largely hampered by the difficulty of _____. ()

completely reversing epigenetic alterations in donor cell nuclei such as DNA methylation and chromatin packing

Bacteria use restriction enzymes to _____.

destroy foreign DNA

In the polymerase chain reaction (PCR), the sequence of bases in the primers is important because it _____. ()

determines which segment of the genome will be amplified

Which of the following is the first step of the Southern blotting procedure? ()

digesting the DNA with a restriction enzyme

During the process of differentiation, cells _____ ()

express different genes in response to cell signaling

The dideoxyribonucleotide chain-termination method _____. ()

find later

A nucleic acid probe is used to _____. ()

identify genes that have been inserted into bacterial plasmids or separated by electrophoresis

In genetic engineering, the highly active plasmid from Agrobacterium tumefaciens is used to _____. ()

insert genes of interest into plant chromosomes

A molecular biologist has isolated a short segment of DNA that she wants to replicate in vitro. First she heats the DNA, which separates the two strands, and then she adds _____. ()

nucleotides, primers, and polymerase

An enzyme that cuts DNA at a symmetrical sequence of bases is called a _____.

restriction enzyme

The term "RFLP" stands for _____. ()

restriction fragment length polymorphism

What is the source of the reverse transcriptase used in recombinant DNA technology? ()

retroviruses

Which arrangement of the following four enzymes represents the order in which they would be used in a typical gene-cloning experiment resulting in the insertion of a cDNA into a bacterial plasmid? Begin with the gene's mRNA transcript. ()

reverse transcriptase, DNA polymerase, restriction enzyme, DNA ligase

In genetic engineering, "sticky end" refers to _____. ()

short bits of single-stranded DNA left at the end of DNA molecules cut by restriction enzymes

DNA fingerprints are used to determine whether Sam could be the father of Becky's baby. Sam is not the father if _____ genetic fingerprint shows some bands not present in _____ genetic fingerprint. ()

the baby's; Sam's or Becky's

When a typical restriction enzyme cuts a DNA molecule, the cuts are staggered so that the DNA fragments have single-stranded ends. This is important in recombinant DNA work because _____.

the fragments will bond to other fragments with complementary single-stranded ends

Transgenic organisms can be scientifically or commercially useful only if _____. ()

the inserted ("foreign") gene is expressed in the host organism

DNA fingerprints used as evidence in a murder trial look something like supermarket bar codes. The pattern of bars in a DNA fingerprint shows _____. ()

the presence of various-sized fragments of DNA

"Therapeutic cloning" refers to _____. ()

the use of cloned embryos as a source of stem cells that could be used to treat disease

RFLPs have been tremendously useful for genomic mapping studies because _____. ()

they are not restricted to genes, and are abundantly scattered throughout the genome

In the polymerase chain reaction (PCR) technique, a heating phase and a cooling phase alternate. An original sample of DNA would have to pass through how many total rounds of heating and cooling before a sample is increased eight times in quantity? ()

three

Because eukaryotic genes contain introns, they cannot be translated by bacteria, which lack RNA-splicing machinery. But if you want to engineer a bacterium to produce a eukaryotic protein, you can synthesize a gene without introns. A good way to do this is to _____. ()

work backward from mRNA to make a version of the gene without introns