Chapter 21 Flashcards
For mapping studies of genomes, most of which were far along before 2000, the three-stage method was often used. Which of the following is the usual order in which the stages were performed, assuming some overlap of the three?
A) genetic map, sequencing of fragments, physical map
B) linkage map, physical map, sequencing of fragments
C) sequencing of entire genome, physical map, genetic map
D) cytogenetic linkage, sequencing, physical map
E) physical map, linkage map, sequencing
B) linkage map, physical map, sequencing of fragments
What is the difference between a linkage map and a physical map?
A) For a linkage map, markers are spaced by recombination frequency, whereas for a physical map they are spaced by numbers of base pairs (bp).
B) For a physical map, the ATCG order and sequence must be achieved; however, it does not for the linkage map.
C) For a linkage map, it is shown how each gene is linked to every other gene.
D) For a physical map, the distances must be calculable in units such as nanometers.
E) There is no difference between the two except in the type of pictorial representation.
A) For a linkage map, markers are spaced by recombination frequency, whereas for a physical map they are spaced by numbers of base pairs (bp).
How is a physical map of the genome of an organism achieved?
A) using recombination frequency
B) using very high-powered microscopy
C) using restriction enzyme cutting sites
D) using sequencing of nucleotides
E) using DNA fingerprinting via electrophoresis
C) using restriction enzyme cutting sites
Which of the following most correctly describes a shotgun technique for sequencing a genome?
A) genetic mapping followed immediately by sequencing
B) physical mapping followed immediately by sequencing
C) cloning large genome fragments into very large vectors such as YACs, followed by sequencing
D) cloning several sizes of fragments into various size vectors, ordering the clones, and then sequencing them
E) cloning the whole genome directly, from one end to the other
D) cloning several sizes of fragments into various size vectors, ordering the clones, and then sequencing them
The biggest problem with the shotgun technique is its tendency to underestimate the size of the genome. Which of the following might best account for this?
A) skipping some of the clones to be sequenced
B) missing some of the overlapping regions of the clones
C) counting some of the overlapping regions of the clones twice
D) having some of the clones die during the experiment and therefore not be represented
E) missing some duplicated sequences
E) missing some duplicated sequences
What is metagenomics?
A) genomics as applied to a species that most typifies the average phenotype of its genus
B) the sequence of one or two representative genes from several species
C) the sequencing of only the most highly conserved genes in a lineage
D) sequencing DNA from a group of species from the same ecosystem
E) genomics as applied to an entire phylum
D) sequencing DNA from a group of species from the same ecosystem
Which procedure is not required when the shotgun approach to sequencing is modified as sequencing by synthesis, in which many small fragments are sequenced simultaneously? A) use of restriction enzymes B) sequencing each fragment C) cloning each fragment into a plasmid D) ordering the sequences E) PCR amplification
C) cloning each fragment into a plasmid
What is bioinformatics?
A) a technique using 3-D images of genes in order to predict how and when they will be expressed
B) a method that uses very large national and international databases to access and work with sequence information
C) a software program available from NIH to design genes
D) a series of search programs that allow a student to identify who in the world is trying to sequence a given species
E) a procedure that uses software to order DNA sequences in a variety of comparable ways
B) a method that uses very large national and international databases to access and work with sequence information
What is proteomics?
A) the linkage of each gene to a particular protein
B) the study of the full protein set encoded by a genome
C) the totality of the functional possibilities of a single protein
D) the study of how amino acids are ordered in a protein
E) the study of how a single gene activates many proteins
B) the study of the full protein set encoded by a genome
Bioinformatics can be used to scan sequences for probable genes looking for start and stop sites for transcription and for translation, for probable splice sites, and for sequences known to be found in other known genes. Such sequences containing these elements are called A) expressed sequence tags. B) cDNA. C) multigene families. D) proteomes. E) short tandem repeats.
A) expressed sequence tags.
A microarray known as a GeneChip, with most now-known human protein coding sequences, has been developed to aid in the study of human cancer by first comparing two to three subsets of cancer subtypes. What kind of information might be gleaned from this GeneChip to aid in cancer prevention?
A) information about whether or not a patient has this type of cancer prior to treatment
B) evidence that might suggest how best to treat a person’s cancer with chemotherapy
C) data that could alert patients to what kind of cancer they were likely to acquire
D) information about which parent might have provided a patient with cancer-causing genes
E) information on cancer epidemiology in the United States or elsewhere
C) data that could alert patients to what kind of cancer they were likely to acquire
What is gene annotation in bioinformatics?
A) finding transcriptional start and stop sites, RNA splice sites, and ESTs
B) describing the functions of protein-coding genes
C) describing the functions of noncoding regions of the genome
D) matching the corresponding phenotypes of different species
E) comparing the protein sequences within a single phylum
A) finding transcriptional start and stop sites, RNA splice sites, and ESTs
Why is it unwise to try to relate an organism’s complexity with its size or number of cells?
A) A very large organism may be composed of very few cells or very few cell types.
B) A single-celled organism, such as a bacterium or a protist, still has to conduct all the complex life functions of a large multicellular organism.
C) A single-celled organism that is also eukaryotic, such as a yeast, still reproduces mitotically.
D) A simple organism can have a much larger genome.
E) A complex organism can have a very small and simple genome.
B) A single-celled organism, such as a bacterium or a protist, still has to conduct all the complex life functions of a large multicellular organism.
Fragments of DNA have been extracted from the remnants of extinct woolly mammoths, amplified, and sequenced. These can now be used to
A) introduce into relatives, such as elephants, certain mammoth traits.
B) clone live woolly mammoths.
C) study the relationships among woolly mammoths and other wool-producers.
D) understand the evolutionary relationships among members of related taxa.
E) appreciate the reasons why mammoths went extinct.
D) understand the evolutionary relationships among members of related taxa.
If humans have 2,900 Mb, a specific member of the lily family has 120,000 Mb, and a yeast has ~13 Mb, why can’t this data allow us to order their evolutionary significance?
A) Size matters less than gene density.
B) Size does not compare to gene density.
C) Size does not vary with gene complexity.
D) Size is mostly due to “junk” DNA.
E) Size is comparable only within phyla.
C) Size does not vary with gene complexity.
