plant ch 10

Crown-gall tumors are produced by a(n): a. virus. b. bacterium. c. fungus. d. alga. e. plant.

b. bacterium.

Distinguish between structural and functional genomics.

Structural genomics deals with the organization and sequence of the genetic information of a genome, whereas functional genomics deals with the functions of genes and their protein products.

Opines are: a. hormones. b. genes. c. amino acid derivatives. d. vitamins. e. enzymes.

c. amino acid derivatives.

A knockout mutant has a particular gene inactivated.

true

Of what value is the study of comparative genomics?

Comparative genomics compares the gene content, function, and organization of the genomes of different organisms. Comparisons of genome sequences are bringing about a greater understanding of the evolutionary relationships among organisms.

Explain how the Ti plasmid of Agrobacterium tumefaciens is used in the production of transgenic plants.

Agrobacterium tumefaciens, with its Ti plasmid, is a powerful tool for genetic engineering of eudicots and certain monocots. The tumor-promoting genes on the T-DNA can be removed and replaced by any genes that researchers wish to transfer to plants. Infection of a plant with A. tumefaciens containing these engineered plasmids will result in transfer of these genes into the plant's genome. Transgenic plants (plants containing foreign genes) obtained through the use of plasmids transmit the foreign genes to their progeny in a Mendelian fashion.

Restriction enzymes cut single-stranded DNA molecules at or near their recognition sequences.

False

Describe the role of sticky ends in recombinant DNA technology. How are sticky ends produced? What enzyme is required to complete their recombination?

Fragments with sticky ends are produced when DNA is cut using a restriction enzyme. When the DNA from two different organisms is cut using the same restriction enzyme, the resulting fragments can readily be joined using DNA ligase, thus producing a recombinant DNA molecule.

What are the uses of restriction enzymes in recombinant DNA technology?

Recombinant DNA technology is based in large part on the ability to precisely cut DNA molecules from different sources into specific pieces and to combine those pieces to produce new combinations. This procedure depends on the existence of restriction enzymes, which recognize specific sequences of double-stranded DNA known as recognition sequences. These sequences are typically four to six nucleotides long and are always palindromic (that is, one strand is identical to the other strand when read in the opposite direction).

Which of the following statements about particle bombardment is FALSE? a. It is used to deliver DNA but not RNA into a cell. b. It involves the use of gold or tungsten beads. c. It involves high-velocity microprojectiles. d. It involves the use of a gene gun. e. It has been used to create a virus-resistant strain of papaya.

a. It is used to deliver DNA but not RNA into a cell.

A sticky-ended fragment can join with another DNA segment only if that segment: a. has been cut with the same restriction enzyme. b. has been cut with the same ligase. c. is palindromic. d. is part of a plasmid. e. is part of a virus.

a. has been cut with the same restriction enzyme.

"Golden rice" is notable because of its: a. high β-carotene content. b. high starch content. c. resistance to herbicides. d. delayed senescence. e. resistance to insect larvae.

a. high β-carotene content.

The preparation of knockout mutants involves: a. inserting a piece of DNA into the gene of interest. b. the use of closely packed DNA fragments attached to a glass slide. c. searching for homology. d. determining the number of base pairs in a gene. e. determining the rate of recombination.

a. inserting a piece of DNA into the gene of interest.

In recombinant DNA technology, reverse transcriptase is used to: a. synthesize cDNA. b. synthesize mRNA. c. cut DNA into fragments. d. amplify a specific gene. e. transfer a plasmid into a cell.

a. synthesize cDNA.

The BT gene is transferred for the purpose of: a. delaying leaf senescence. b. reducing the proportion of saturated fats. c. conferring resistance to caterpillars. d. conferring resistance to herbicides. e. delaying fruit ripening.

c. conferring resistance to caterpillars.

Why would a gene for cytokinin synthesis be fused to a promoter that is expressed only in senescent leaves? a. to delay leaf senescence b. to confer resistance to herbicides c. to confer resistance to BT toxin d. to increase starch content e. to increase glyphosate production

a. to delay leaf senescence

Because meristems lack _________ tissues, meristem culture results in plants that lack _________. a. vascular; viruses b. vascular; fungi c. epidermal; viruses d. epidermal; fungi e. epidermal; insect eggs

a. vascular; viruses

Which of the following statements about prokaryotic genomes is FALSE? a. Most consist of a single circular chromosome. b. Approximately 90% of the identified genes have been assigned a function. c. About 25% of the genes have no significant similarity to other known genes in bacteria. d. Horizontal gene exchange periodically occurs. e. Gene transfers have occurred between bacteria and eukaryotes.

b. Approximately 90% of the identified genes have been assigned a function.

In the Agrobacterium Ti plasmid, the ____ gene codes for the synthesis of amino acids that are used as food. a. R b. O c. onc d. vir e. A

b. O

The first eukaryotic genome to be sequenced was that of: a. Haemophilus influenzae. b. Saccharomyces cerevisae. c. Arabidopsis thaliana. d. Agrobacterium tumefaciens. e. Caenorhabditis elegans.

b. Saccharomyces cerevisae.

Suppose a plasmid containing a gene of interest plus the ampR gene is used to transform E. coli cells. When these cells are placed on a medium containing ampicillin, what will happen? a. They will die. b. They will survive and grow. c. They will form blue colonies. d. They will glow with a green color. e. They will glow when provided with luciferin plus ATP

b. They will survive and grow.

A genetic map is different from a physical map in that a genetic map is: a. used to determine the function of genes. b. based on rates of recombination. c. used to determine which genes are inactivate. d. based on direct DNA sequencing. e. based on evolutionary relationships

b. based on rates of recombination.

One advantage of inserting into crop plants a gene that codes for an altered enzyme in aromatic amino acid synthesis is that the plants would: a. be resistant to BT toxin. b. be resistant to glyphosphate. c. be resistant to Bacillus thuringiensis. d. have an increased starch content. e. have an increased vitamin A content.

b. be resistant to glyphosphate.

By definition, a transformed cell: a. contains a plasmid. b. contains a recombinant DNA molecule. c. contains a virus. d. functions as a vector. e. divides in such a way so as to amplify the DNA fragment

b. contains a recombinant DNA molecule.

It was not until the discovery of ________ that organ and tissue culture became feasible. a. hydroponics b. plant hormones c. the importance of sucrose in nutrient solutions d. the essential mineral elements

b. plant hormones

The polymerase chain reaction is used to: a. determine where gene promoters are active. b. produce millions of copies of a DNA segment in a short time. c. determine if a gene inserted into a cell is active or inactive. d. produce a cDNA library. e. transform a cell.

b. produce millions of copies of a DNA segment in a short time.

Genetically modified plants were first grown commercially in: a. 1965. b. 1985. c. 1996. d. 2001. e. 2009.

c. 1996.

Which of the following statements about eukaryotic genomes is FALSE? a. They are larger than those of prokaryotes. b. In general, multicellular eukaryotes have more DNA than unicellular eukaryotes. c. The greater the complexity of the organism, the more protein-coding genes it has. d. The roundworm Caenorhacditis has more genes than the fruit fly Drosophila. e. The plant Arabidopsis has more genes than the fruit fly Drosophila.

c. The greater the complexity of the organism, the more protein-coding genes it has.

Which of the following statements concerning restriction enzymes is FALSE? a. They are a type of endonuclease. b. They recognize DNA sequences typically four to six nucleotides long. c. They recognize single-stranded DNA sequences. d. Some make straight cuts in the DNA. e. They recognize specific palindromic sequences.

c. They recognize single-stranded DNA sequences.

When the lacZ gene technique is used to detect recombinant DNA in host bacterial cells, the colonies will appear _______ if the cells have been successfully transformed. a. red b. white c. blue d. green e. fluorescent

c. blue

The Taq polymerase is used in recombinant DNA technology to: a. locate specific DNA segments. b. determine the nucleotide sequence of a specific gene. c. make up to a millionfold copies of a DNA segment in a few hours. d. make cDNA. e. carry out "shotgun cloning."

c. make up to a millionfold copies of a DNA segment in a few hours.

In Agrobacterium, genes that code for enzymes involved in the synthesis of the hormone auxin are found in the _____ region of the plasmid. a. R b. O c. onc d. vir e. A

c. onc

One aspect of structural genomics is: a. determining the function of genes. b. determining the function of gene products. c. preparing physical maps. d. preparing knockout mutants. e. comparing evolutionary relationships

c. preparing physical maps.

The ampR gene is used in recombinant DNA technology to: a. produce β-galactosidase. b. clone a particular gene fragment. c. screen for the presence of cells containing recombinant plasmids. d. help the bacterium to survive on a medium containing lactose. e. transform a bacterial cell.

c. screen for the presence of cells containing recombinant plasmids.

Agrobacterium induces the formation of crown-gall tumors by transferring the ____ plasmid containing ______ to the host plant's nuclear DNA. a. CG; CG-DNA b. O; R-DNA c. C; C-DNA d. Ti; T-DNA e. T-DNA; Ti

d. Ti; T-DNA

Glyphosate is: a. an enzyme in amino acid synthesis. b. a mutant gene from Arabidopsis. c. toxic to animals. d. an herbicide that kills all plants e. a mutant gene from Salmonella.

d. an herbicide that kills all plants

In the Ti plasmid of Agrobacterium tumefaciens, the onc region contains genes that code for enzymes in: a. auxin synthesis only. b. opine synthesis only. c. cytokinin synthesis only. d. auxin and cytokinin synthesis. e. auxin and opine synthesis

d. auxin and cytokinin synthesis.

Traditional breeding programs: a. involve inserting a plasmid into a host cell. b. involve infecting a host plant with a virus. c. allow gene transfers between species incapable of hybridizing. d. depend on inherent genetic variability. e. allow the precise insertion of genes into a plant.

d. depend on inherent genetic variability.

The advantage of using the "ice-minus" strain of Pseudomonas syringae is: a. reducing susceptibility to fungi. b. increasing resistance to bacteria that thrive at low temperatures. c. increasing resistance to herbicides. d. reducing susceptibility to frost. e. increasing resistance to insect larvae.

d. reducing susceptibility to frost.

One important characteristic the Taq polymerase is its a. insensitivity to pH. b. ability to glow when in the presence of a suitable substrate. c. ability to be cloned. d. resistance to high temperature. e. ability to transform cells.

d. resistance to high temperature.

Which of the following statements concerning DNA libraries is FALSE? a. A genomic library is obtained by cutting the entire genome of an organism. b. A cDNA library is obtained by using reverse transcriptase. c. A DNA library contains cloned fragments of most of an organism's genome. d. A cDNA library lacks introns. e. A genomic library lacks exons.

e. A genomic library lacks exons.

Which of the following statements concerning vectors is FALSE? a. Vectors are used to transform cells. b. Vectors function as DNA carriers. c. A virus can be a vector. d. A plasmid can be a vector. e. A host cell can be a vector

e. A host cell can be a vector

The transcriptome refers to all of the: a. proteins encoded by the genome. b. glycoproteins transcribed by the genome. c. nucleotides present in a cell's DNA. d. nucleotides present in a cell's RNA. e. RNA molecules transcribed by the genome.

e. RNA molecules transcribed by the genome.

An example of a selectable marker gene is: a. the gene for a green fluorescent protein. b. the luciferase gene. c. EcoRI. d. lacZ. e. ampR.

e. ampR.

Mutant forms of the ethylene receptor gene from Arabidopsis are inserted into plants for the purpose of: a. increasing starch content. b. increasing levels of β-carotene. c. stimulating fruit ripening. d. conferring resistance to pesticides. e. delaying flower wilting.

e. delaying flower wilting.

In recombinant DNA technology, cutting different samples of a single DNA molecule with different restriction enzymes allows one to: a. amplify the DNA molecule. b. carry out DNA hybridization. c. locate a gene of interest. d. determine the function of a gene. e. determine the nucleotide sequence of a gene.

e. determine the nucleotide sequence of a gene.

Which of the following is NOT one of the goals of functional genomics? a. identifying the transcriptome b. identifying the proteome c. determining the function of genes d. determining which genes are expressed e. determining the location of genes on a chromosome

e. determining the location of genes on a chromosome

In _________, electrical pulses cause pores in the plasma membrane to open, thus allowing DNA to enter the cell. a. particle bombardment b. the polymerase chain reaction c. a reaction involving reverse transcriptase d. electrophoresis e. electroporation

e. electroporation

DNA ligase would most likely be used in recombinant DNA technology to: a. function as a vector. b. screen for recombinant plasmids. c. stimulate a transformed cell to divide. d. cut DNA into fragments with sticky ends. e. join DNA fragments together.

e. join DNA fragments together.

By definition, hydroponics is the technique for growing: a. shoot tips. b. isolated leaf pieces. c. isolated roots d. plant embryos. e. plants without soil.

e. plants without soil.

Which of the following would be linked to a promoter to determine if a particular gene introduced into a host cell is directing the synthesis of protein? a. ampR b. lacZ c. X-gal d. EcoRI e. the luciferase gene

e. the luciferase gene

Agrobacterium tumefaciens receives the Ti plasmid from its host plant.

false

Cells containing the gene ampR would not survive when incubated on a medium containing ampicillin.

false

Electroporation is used to transform monocots because Agrobacterium tumefaciens cannot infect them.

false

Identical DNA fragments are obtained by cutting the same DNA molecule with different restriction enzymes.

false

In eukaryotes, the more complex the organism the more genes it has.

false

Most of the genes in all bacteria are significantly similar.

false

Particle bombardment and electroporation are the two techniques most widely used to transfer DNA into plants.

false

Sticky-ended fragments can be joined by specific restriction enzymes.

false

The proteome refers to all the protein molecules transcribed by the DNA.

false

When you grow a plant hydroponically, by definition you grow it without its roots in water.

false

A search for homology would be used to determine the possible function of a gene.

true

Agrobacterium tumefaciens is used to obtain transgenetic plants.

true

DNA fragments having sticky ends can join with other fragments obtained by using the same restriction enzyme.

true

Horizontal/lateral gene exchange refers to related bacterial species exchanging genetic information over evolutionary time.

true

Micropropagation is used to obtain clones of plants.

true

Nowadays, DNA sequencing is rarely done from specific restriction fragments.

true

One advantage of meristem culture is that virus-free plants can be obtained.

true

One of the risks associated with genetic engineering is the spread of genes to weedy relatives by hybridization.

true

Random clones are regularly used to obtain the nucleotide sequences of isolated genes.

true

The Ti plasmid of Agrobacterium tumefaciens contains genes for plant hormones as well as genes for molecules that nourish the bacterium.

true

The polymerase chain reaction is used to quickly make many copies of a DNA segment.

true

Totipotency refers to the ability of an individual plant cell to grow into an entire plant.

true