Bio Chapter 20

Which of the following is an example of "recombinant DNA technology?" A) combining alternate alleles of a gene in a single cell B) introducing a human gene into a bacterial plasmid C) manipulating a meiotic crossing-over event D) alternate alleles assorting independently E) cloning genes from homologous pairs of chromosomes

Why are yeast cells frequently used as hosts for cloning? A) They easily form colonies. B) They are eukaryotic cells. C) They do not have plasmids. D) They can remove exons from mRNA. E) Only yeast cells allow the gene to be cloned.

A researcher needs to clone a particular DNA sequence in order to express the sequence and to modify the polypeptide product. She would be able to satisfy these requirements by using which of the following vectors? A) a yeast plasmid B) a human chromosome C) a modified bacteriophage D) a bacterial plasmid E) a BAC to accommodate the size of the sequence

To introduce a particular piece of DNA into an animal cell, such as that of a mouse, you would find more probable success with which of the following methods? A) transcription and translation B) introducing a plasmid into the cell C) infecting the mouse cell with a Ti plasmid D) the shotgun approach E) electroporation followed by recombination

Why is it so important to be able to amplify DNA fragments when studying genes? A) A gene may represent only a millionth of the cell's DNA. B) Restriction enzymes cut DNA into fragments that are too small. C) DNA fragments are too small to use individually. D) A clone requires multiple copies of each gene per clone. E) It is important to have multiple copies of DNA in the case of laboratory error.

Gel electrophoresis separates DNA fragments on the basis of what characteristic? A) length B) charge C) restriction sites D) sequence E) mutations

Which of the following modifications is least likely to alter the rate at which a DNA fragment moves through a gel during electrophoresis? A) decreasing the length of the DNA fragment B) altering the nucleotide sequence of the DNA fragment without adding or removing nucleotides C) neutralizing the negative charges within the DNA fragment D) acetylating the cytosine bases within the DNA fragment E) increasing the length of the DNA fragment

If cells from a carrot are removed and placed in a culture medium, they can develop into a normal adult plant. This demonstrates that carrot cells _____. A) are undifferentiated as adult cells B) differ genetically at maturity C) differ as mature cells D) differentiate E) retain all the genes that were in the zygote that developed into the original plant

Which of the following is true of stem cells? A) They can differentiate to produce many different kinds of specialized cells. B) They can reproduce indefinitely in culture. C) Their use is highly controversial. D) They can be found in both embryonic and adult tissues. E) All of the above.

Which of the following is most closely identical to the formation of twins? A) therapeutic cloning B) cell cloning C) use of adult stem cells D) embryo transfer E) organismal cloning

In 1997, Dolly the sheep was cloned. Which of the following processes was used? A) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate B) separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe C) isolation of stem cells from a lamb embryo and production of a zygote equivalent D) replication and dedifferentiation of adult stem cells from sheep bone marrow E) use of mitochondrial DNA from adult female cells of another ewe

Which of the following problems with animal cloning might result in premature death of the clones? A) abnormal gene regulation due to variant methylation B) the indefinite replication of totipotent stem cells C) use of pluripotent instead of totipotent stem cells D) abnormal immune function due to bone marrow dysfunction E) use of nuclear DNA as well as mtDNA

Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning there is a wider divergence of opinion. Which of the following is a likely explanation? A) A clone that lives until the blastocyst stage does not yet have human DNA. B) Cloning to produce embryonic stem cells may lead to great medical benefits for many. C) No embryos would be destroyed in the process of therapeutic cloning. D) Use of adult stem cells is likely to produce more cell types than use of embryonic stem cells. E) Cloning to produce stem cells relies on a different initial procedure than reproductive cloning.

Which of the following is true of embryonic stem cells but not of adult stem cells? A) One aim of using them is to provide cells for repair of diseased tissue. B) They normally differentiate into only eggs and sperm. C) They can give rise to all cell types in the organism. D) They can provide enormous amounts of information about the process of gene regulation. E) They can continue to reproduce for an indefinite period.

A researcher is using adult stem cells and comparing them to other adult cells from the same tissue. Which of the following is a likely finding? A) The nonstem cells have lost the promoters for more genes. B) The two kinds of cells have virtually identical gene expression patterns in microarrays. C) Adult stem cells have more DNA nucleotides than their counterparts. D) The nonstem cells have fewer repressed genes. E) The cells from the two sources exhibit different patterns of DNA methylation.

The first cloned cat, called Carbon Copy, was a calico, but she looked significantly different from her female parent. Why? A) Fur color genes in cats are influenced by differential acetylation patterns. B) Cloned animals have been found to have a higher frequency of transposon activation C) X inactivation in the embryo is random and produces different patterns. D) The environment, as well as genetics, affects phenotypic variation. E) The telomeres of the parent's chromosomes were shorter than those of an embryo.

In animals, what is the difference between reproductive cloning and therapeutic cloning? A) Reproductive cloning uses embryonic stem cells, whereas therapeutic cloning does not. B) Therapeutic cloning uses nuclei of adult cells transplanted into enucleated nonfertilized eggs. C) Therapeutic cloning supplies cells for repair of diseased or injured organs. D) Reproductive cloning uses totipotent cells, whereas therapeutic cloning does not.

What is the most commonly used vector for introducing transgenes into plants? A) beta-carotene B) the Ti plasmid C) the flu virus D) nuclear transplantation E) the bacterium Bacillus thuringiensis