BIOLOGY CHAPTER 14 LEARNING CURVE QUESTIONS

question

Mutations:
answer

can leave the protein sequence intact.
question

Insertion of one nucleotide in a gene will lead to a frameshift mutation.
answer

true
question

Chromosomal aberrations:
answer

can be caused by errors during cell division.
question

DNA ligase is responsible for repairing thymine dimers caused by UV light.
answer

false
question

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?
answer

frameshift
question

Chronic myelogenous leukemia (CML) is caused when a segment of chromosome 9 and a segment of chromosome 22 both break off and switch places. How is this mutation classified?
answer

reciprocal translocation
question

Mutagens increase the amount of damage to DNA.
answer

true
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:
answer

most of a human’s DNA is noncoding, so most of the mutations are neutral.
question

Normally in corn, genes for waxy and virescent kernel appearance are linked. In a certain stock, however, it was found that these two genes assort independently. Which chromosomal aberration would explain this?
answer

translocation
question

Dosage refers to the number of copies of each gene in a chromosome.
answer

true
question

DNA repair:
answer

can involve excision of bases flanking a distortion in the helix.
question

Which of the following statements concerning cancer and mutations is correct?
answer

Usually multiple mutations are required in different genes to cause cancer.
question

Generally speaking, a nucleotide substitution has less severe consequences than a nucleotide addition/deletion.
answer

true
question

A chromosomal mutation in which a segment (not containing a centromere) is missing is called a deletion.
answer

true
question

In base excision repair, a whole segment of DNA is removed and resynthesized.
answer

false
question

Mutation rates (of nucleotides):
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?
answer

GUA
question

_____ is the process where new genes evolve from duplicates of old ones.
answer

Duplication and divergence
question

Duplication and divergence
answer

false
question

The amount of new mutations in living organisms following a round of genome replication:
answer

generally increases with larger genomes.
question

The GAG codon, which codes for glutamic acid, is mutated to GUG, which now codes for valine. What type of mutation is this?
answer

missense
question

Any deviation in normal gene dosage is lethal.
answer

false
question

Which of the following enzymes is responsible for initiating certain types of base excision repair?
answer

DNA uracil glycosylase
question

Spontaneous mutations that occur in somatic cells will be transmitted to offspring.
answer

false
question

A point mutation that now codes for the wrong amino acid is called a:
answer

missense mutation
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:
answer

either a deletion or a reciprocal translocation.
question

The use of antibiotics is creating the mutations in bacteria that make them resistant to these antibiotics.
answer

false
question

The rates of evolutionary change in DNA:
answer

are highly variable among different gene families.
question

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

Which of the following would you expect to have the lowest nucleotide mutation rate?
answer

humans
question

Mutations will always decrease the activity of a gene.
answer

false
question

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

A point mutation is when a single nucleotide gets replaced by a different one.
answer

true
question

Sites in the genome that are more susceptible to mutations are called:
answer

hotspots
question

What is one reason that RNA viruses and retroviruses have such a high rate of mutation?
answer

because RNA is more fragile than DNA and because viral polymerases lack a proofreading mechanism.
question

Movable DNA sequences that can “jump” from one spot in the genome to another are called transposable elements.
answer

true
question

Genetic risk factors:
answer

-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.
question

You are working in a lab studying a gene and notice that there are many other genes that code for similar traits. This is most likely the result of:
answer

duplication and divergence.
question

Sickle-cell anemia is an example of what type of mutation?
answer

missense
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?
answer

21
question

Which of the following statements is true concerning the work of the Esther and Joshua Lederberg?
answer

Their work relied on a technique of bacterial culture known as “replica-plating,” and demonstrated that mutations occur randomly within organisms.
question

Which of the following statements is true of a chromosome inversion?
answer

-An inversion usually results from breakages in non-coding DNA. -An inversion results in the “flipping” of certain chromosomal segments. -Inversions can alter the order of genes within a chromosome. -Inversions are not always fatal for an organism.
question

A chromosomal mutation where a segment breaks off, flips, and then reattaches itself is called a(n):
answer

inversion
question

Which of the following would best describe the results seen in a flower whose sectors have different pigmentation?
answer

the result of transposable elements
question

Any DNA “damage” is considered to be a mutation, even if it is immediately correct by the action of DNA polymerase.
answer

false
question

A chromosomal segment that breaks off and inserts into another chromosome is what type of mutation?
answer

translocation

Get instant access to
all materials

Become a Member