W8 PCRQs

Insertions and deletions of single nucleotides: (a) cause frameshift mutations. (b) cause missense mutations. (c) shorten chromosomes. (d) cause cancer. (e) add or delete amino acids to or from the normal polypeptide.

(a) cause frameshift mutations.

Which are examples of sequence motifs? (a) open reading frame (ORF) (b) coding region (c) All of these choices are correct. (d) hairpin structures (e) promoters

(c) All of these choices are correct.

Which pair of people has the exact same genome? (a) dizygotic twins (b) mother and daughter (c) father and son (d) monozygotic twins (e) None of the other answer options is correct.

(d) monozygotic twins

Genome annotation includes all of the followings except: (a) regulatory sequences (b) start codons (c) locations of genes (d) none of these (e) conserved sequences

(d) none of these

Aneuploidy can result due to which type of mutation(s). - base substitution - duplication - translocation - base insertion - nonsense mutation - frame shift mutation - deletion

- duplication - translocation - deletion

Sequencing the genome of cancer cells from patients can detect: - protein isoforms - none of these - large scale chromosome mutations such as a translocation and inversion - single nucleotide deletions - all of these - point mutations such as base substitutions

- large scale chromosome mutations such as a translocation and inversion - single nucleotide deletions - point mutations such as base substitutions

Point mutations can impair a protein if they result in which of the answer choices? Select all that apply. - synonymous codon - shift in reading frame - nonsynonymous codon - nonsense codon

- shift in reading frame - nonsynonymous codon - nonsense codon

(T/F) A chromosomal mutation in which a segment is missing is called a deletion.

True

Imagine that a researcher is comparing the sequence of seven protein-coding genes among mice, rabbits, and humans. She finds that for five of these genes the rabbit sequences are more similar to the human sequences than are the mouse sequences. What can she deduce? (a) More sequences are conserved between rabbits and humans than between humans and mice. (b) Mice and humans share a more "recent" common ancestor than do rabbits and humans. (c) Humans and mice do not share a common ancestor. (d) Mice and rabbits do not share a common ancestor.

(a) More sequences are conserved between rabbits and humans than between humans and mice.

Which group lists the levels of genetic information in order from smallest to largest. (a) exon, gene; chromosome; genome (b) exon; chromosome; gene; genome (c) genome; gene; chromosome; exon (d) gene; chromosome; exon; genome (e) exon; gene; genome; chromosome

(a) exon, gene; chromosome; genome

Mutation rate in germ-line cells occur___________________ in somatic cells. (a) less often than (b) more often than (e) at the same rate as

(a) less often than

When nonhomologous chromosomes exchange parts, a(n) _____ has occurred. (a) reciprocal translocation (b) mismatch (c) closed reading frame (d) base exclusion (e) inversion

(a) reciprocal translocation

Repeated DNA sequences represent a special challenge in genome sequence assembly. Which would be harder to assemble correctly, assuming the number of copies of the repeat can be determined? (a) sequences containing repeats longer than the DNA fragments to assemble (b) sequences containing repeats shorter than the DNA fragments to assemble

(a) sequences containing repeats longer than the DNA fragments to assemble

Deletions that eliminate a multiple of three nucleotides can: (a) cause nonsense mutations in an open reading frame. (b) delete amino acids in a polypeptide chain. (c) cause frameshift mutations in an open reading frame. (d) All of these choices are correct.

(b) delete amino acids in a polypeptide chain.

In what situation can a harmful deletion in a chromosome persist in a population? (a) if a transposon replaces the deleted region (b) if the homologous chromosome lacks the deletion (c) if it is homozygous (d) if the deletion is in the centromere

(b) if the homologous chromosome lacks the deletion

Imagine a gene in which the sequence that is transcribed has a GAG codon, which specifies glutamic acid. If the codon mutated to GUG, which specifies valine, what type of mutation would it be? (a) base pair deletion (b) missense (c) silent (d) nonsense (e) frameshift

(b) missense

A chromosomal segment that breaks off and attaches to another chromosome is what type of mutation? (a) inversion (b) duplication (c) translocation (d) deletion (e) reciprocal translocation

(c) translocation

The following are examples of small-scale mutations except: (a) single nucleotide insertion (b) frame shift mutation (c) translocation (d) single nucleotide deletion (e) base substitution

(c) translocation

Which property of transposable elements allows them to contribute to the C-value paradox? (a) Their copy number can increase from one generation to the next. (b) Their replication is controlled by genes found on the transposable element itself. (c) Copies of transposable elements can appear on multiple chromosomes. (d) All of these choices are correct.

(d) All of these choices are correct.

How can researchers distinguish exons from introns in a segment of DNA? (a) Exons have a characteristic sequence. (b) Only exons contain three-base sequences that can code for amino acids. (c) Primers will not bind to introns. (d) The sequence of exons complements mRNA molecules in the cell.

(d) The sequence of exons complements mRNA molecules in the cell.

A chromosomal mutation where a segment breaks off, flips, and then reattaches itself is called a(n): (a) translocation. (b) reciprocal translocation. (c) duplication. (d) inversion. (e) deletion.

(d) inversion

A point mutation that changes a UAC codon into a UAG codon is a: (a) missense mutation. (b) frameshift mutation. (c) silent mutation. (d) nonsense mutation.

(d) nonsense mutation

A point mutation that causes an amino acid replacement is called a: (a) transition mutation. (b) synonymous (silent) mutation. (c) nonsense mutation. (d) nonsynonymous (missense) mutation. (e) stop mutation.

(d) nonsynonymous (missense) mutation.

A single base deletion within the open reading frame of a gene's DNA sequence can result in ____________. (a) replacement of a correct amino acid with a premature stop codon (b) replacement of a correct amino acid with an alternative amino acid (c) all of the above (d) replacement of multiple correct amino acids with alternative amino acids

(d) replacement of multiple correct amino acids with alternative amino acids

Which is a type of sequence identified by gene annotation? (a) open reading frame (ORF) (b) tandem repeat (c) simple-sequence repeat (d) noncoding RNA (e) All of these choices are correct.

(e) All of these choices are correct.

Which of the statements applies to frameshift mutations? (a) Frameshift mutations create a premature stop codon at the site of the mutation. (b) Frameshift mutations are known risk factors in breast cancer, but not colon cancer. (c) Frameshift mutations cause the insertion or deletion of a single amino acid from the polypeptide chain. (d) Frameshift mutations are known risk factors in most forms of cancer, including breast and colon cancer. (e) Frameshift mutations change the amino acid sequence downstream from the site of the mutation.

(e) Frameshift mutations change the amino acid sequence downstream from the site of the mutation.

Which step comes first in shotgun sequencing? (a) putting the sequences in the correct order (b) matching regions of overlap (c) sequencing the DNA (d) reconstructing the long sequence of nucleotides (e) breaking the DNA into small fragments

(e) breaking the DNA into small fragments

In organisms with large genomes, inversions are more likely to be tolerated if the breakpoints occur in: (a) reciprocal translocations. (b) closed reading frames. (c) coding DNA. (d) open reading frames. (e) noncoding DNA.

(e) noncoding DNA.

Humans do not have significantly more genes than some other animals, for instance, the nematode worm C. elegans. What accounts for the diversity of cell types and functions in humans relative to C. elegans or D. melanogaster? Select all that apply. - Humans cells frequently gain more genes through horizontal gene transfer. - Complexity arises from different combinations of proteins. - Most genes in the other animals are inactive. - Complexity arises from differential gene expression. - Many human genes can encode multiple proteins.

- Complexity arises from different combinations of proteins. - Complexity arises from differential gene expression. - Many human genes can encode multiple proteins.

Imagine a genomic researcher who is analyzing the genome of different types of cats. She finds that a particular sequence in the North American Bobcat genome is identical to a sequence found in the common house cat, whereas most other sequences between the genomes of these cats differ at many nucleotides. Bobcats and house cats diverged an estimated 6.8 million years ago, plenty of time for mutation to generate DNA sequence variation. Which statements could explain the identical sequence in these otherwise differing genomes? Select all that apply. - The sequence encodes a protein critical for the production of fur color. - The sequence encodes a gene that is critical for life and that cannot retain its function if mutated. - The sequence is from an intron of a gene that encodes a muscle protein. - The sequence is contained in a retrovirus that has infected both species.

- The sequence encodes a gene that is critical for life and that cannot retain its function if mutated. - The sequence is contained in a retrovirus that has infected both species.

Which of the point mutations is unlikely to change a protein's ability to function? Select all that apply. - one that creates a new codon code for the same amino acid as the original codon - one that occurs in somatic cells - one that occurs in a noncoding region of DNA - one that occurs in germ cells - one that creates a new codon that does not code for any amino acid

- one that creates a new codon code for the same amino acid as the original codon - one that occurs in a noncoding region of DNA

(T/F) A gain-of-function mutation in a tumor suppressor gene would result in abnormal cell proliferation and growth.

False

(T/F) All DNA sequences are transcribed into RNA.

False

(T/F) The complexity of an organism is proportional to the number of genes in its genome.

False

(T/F) To maintain the accuracy of the genome sequence, the DNA should not be cut into small pieces before sequencing.

False

(T/F) In DNA sequencing, the newly synthesized DNA strand that is complementary and anti-parallel to a template DNA strand is called a sequence read.

True

(T/F) Sequencing reads can be aligned to a reference genome (i.e., human genome) to identify single nucleotide variants and potential mutations.

True

(T/F) When an open reading frame (ORF) is identified, it may not actually correspond to the amino acid sequence of any polypeptide in the cell.

True