BIOL 2170 Chapter 14 Learning Curve – Flashcards

Unlock all answers in this set

Unlock answers
question
T/F: Mutations will always decrease the activity of a gene.
answer
false
question
T/F: Movable DNA sequences that can "jump" from one spot in the genome to another are called transposable elements.
answer
true
question
T/F: Dosage refers to the number of copies of each gene in a chromosome.
answer
true
question
T/F: DNA polymerase is responsible for the process called mismatch repair.
answer
false
question
What is one reason that RNA viruses and retroviruses have such a high rate of mutation? because RNA viruses and retroviruses initially cause mutations during replication because RNA is more fragile than DNA and therefore more likely to be damaged because they lack a proofreading mechanism because RNA replication is much more prone to mistakes because RNA is more fragile than DNA and because viral polymerases lack a proofreading mechanism.
answer
because RNA is more fragile than DNA and because viral polymerases lack a proofreading mechanism.
question
The GAG codon, which codes for glutamic acid, is mutated to GUG, which now codes for valine. What type of mutation is this? silent missense base pair deletion frameshift nonsense
answer
missense
question
T/F: A chromosomal mutation in which a segment (not containing a centromere) is missing is called a deletion.
answer
true
question
DNA repair: can involve excision of bases flanking a distortion in the helix. can fix chromosomal inversions and translocations. always prevents errors. is only active during DNA replication. involves a set of proteins that are always active.
answer
can involve excision of bases flanking a distortion in the helix.
question
Which of the following statements concerning cancer and mutations is correct? Cancer can only occur with a mutation in a somatic cell. Cancer can only occur with a mutation in a germ cell. Usually multiple mutations are required in different genes to cause cancer. Usually a single mutation is all that is required to cause cancer. None of the answer options is correct.
answer
Usually multiple mutations are required in different genes to cause cancer.
question
Sickle-cell anemia is an example of what type of mutation? silent base pair deletion missense frameshift nonsense
answer
missense
question
A chromosomal segment that breaks off and inserts into another chromosome is what type of mutation? reciprocal translocation duplication deletion inversion translocation
answer
translocation
question
Which of the following mechanisms would most likely be involved in repairing a single point mutation? nucleotide excision repair base excision repair base excision repair and/or nucleotide excision repair mismatch repair and/or base excision repair mismatch repair
answer
mismatch repair and/or base excision repair
question
The fact that humans have a relatively large number of mutations per genome per generation when compared to other organisms can be explained by: humans are so complex we have multiple proteins doing the same job. human cells don't divide as often as those of other organisms. most of a human's DNA is noncoding, so most of the mutations are neutral. humans have multiple proteins doing the same job, and our cells don't divide as often as other those of other organisms. most of these mutations happen after reproduction, so they wouldn't be selected against.
answer
most of a human's DNA is noncoding, so most of the mutations are neutral.
question
T/F: A point mutation is when a single nucleotide gets replaced by a different one.
answer
true
question
T/F: Any deviation in normal gene dosage is lethal.
answer
false
question
What is the difference between mismatch repair and nucleotide excision repair? In mismatch repair, several nucleotides are replaced, whereas in nucleotide excision repair the sugar phosphate backbone is fixed. In mismatch repair, one nucleotide is replaced, whereas in nucleotide excision repair several nucleotides are replaced. In mismatch repair, the sugar phosphate backbone is fixed, whereas in nucleotide excision repair, several nucleotides are replaced. In mismatch repair, several nucleotides are replaced, whereas in nucleotide excision repair it is just one.
answer
In mismatch repair, one nucleotide is replaced, whereas in nucleotide excision repair, several nucleotides are replaced.
question
T/F: Even though the chance of a mutation for one given nucleotide is rare, mutations are rather common when looking at the whole genome.
answer
true
question
T/F: Generally speaking, a nucleotide substitution has less severe consequences than a nucleotide addition/deletion.
answer
true
question
A researcher has carried out Giesma staining on a set of human chromosomes, and has arranged these chromosomes into a karyotype. She notices that in a homologous pair, a band is missing from one of the chromosomes. This likely resulted from: a deletion. a duplication. an inversion. a reciprocal translocation. either a deletion or a reciprocal translocation.
answer
either a deletion or a reciprocal translocation
question
T/F: Loss of a pyrimidine base is one of the most common types of DNA damage.
answer
false
question
T/F: Spontaneous mutations that occur in somatic cells will be transmitted to offspring.
answer
false
question
Mutation rates (of nucleotides): are lower in organisms with larger genomes. are higher in organisms with larger genomes. are highest in viruses. are similar across all organisms. are highest in the bacteria.
answer
are highest in viruses.
question
A trinucleotide of 5'CTC3' or 5'TTC3' is transcribed and then translated into the amino acid glutamic acid. A trinucleotide of 5'CAA3' or 5'TAC3' is transcribed and then translated into valine. In sickle-cell hemoglobin, valine is present instead of glutamic acid. Assuming a single base pair substitution has occurred, what is the mRNA code for valine in the affected mutant? GAG GAA GUA CUU UUG
answer
GUA
question
The amount of new mutations in living organisms following a round of genome replication: generally increases with larger genomes. generally decreases with larger genomes. is similar independent of genome size. is highest in the bacteria. None of the answer options is correct.
answer
generally increases with larger genomes
question
The rates of evolutionary change in DNA: can only be determined in conserved genes. are constant among different gene families and thus are used to estimate the time of divergence. are zero. are highly variable among different gene families. are constant in gene families with a diversity of members.
answer
are highly variable among different gene families.
question
Which of the following would you expect to have the lowest nucleotide mutation rate? DNA viruses fruit flies humans bacteria RNA viruses
answer
humans
question
T/F: Only germ line mutations are transmitted to the progeny.
answer
true
question
Which of the following mutations would most likely have the most severe consequence? addition of a codon missense silent frameshift
answer
frameshift
question
T/F: Consider a polyploid plant that has several copies of each of its genes. This plant will likely die prematurely, given this high gene dosage.
answer
false
question
T/F: The use of antibiotics is creating the mutations in bacteria that make them resistant to these antibiotics.
answer
false
question
T/F: Any DNA "damage" is considered to be a mutation, even if it is immediately correct by the action of DNA polymerase.
answer
false
question
Genetic risk factors: can increase the likelihood of somatic mutations. can increase the likelihood of germ-line mutations. can work synergistically with environmental risk factors. can be heritable. All of the answer options are correct.
answer
All of the answer options are correct.
question
Imagine that a researcher is studying a mouse that carries a mutation in Pax7 ―a gene that is involved in muscle development. To his surprise, these Pax7 mutant mice appear relatively "normal." What is a possible explanation for this? Other members of the Pax gene family have redundant functions in muscle development (and can compensate for the Pax7 mutation). The normal copy of Pax7 on the corresponding homologous chromosome is sufficient for mouse survival. These Pax7 mutant mice may have a synonymous mutation. All answer options are correct.
answer
All answer options are correct.
question
Which of the following statements is true regarding a chromosome deletion? Chromosome deletions have no relationship to gene dosage. If a deletion affects a centromere, this mutated chromosome will be easily passed on during cell division. Chromosomal deletions also have serious―typically fatal―ramifications for an organism. Chromosome deletions are always fatal due to the presence of homologous chromosomes. None of the answer options are true.
answer
None of the answer options are true.
question
When comparing DNA sequences of similar genes for proteins in related species, you see that some of the sequences are longer in one species compared to the other. Which of the following would most likely represent the extra number of bases that you would see? 5 7 21 17 25
answer
21
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New