Which of the following enzymes is responsible for "unzipping" a DNA molecule in preparation for its replication?
primase DNA polymerase DNA ligase DNA helicase
A haploid cell has __________. more than one chromosome only one chromosome two copies of each chromosome a single copy of each of its chromosomes
a single copy of each of its chromosomes
Which of the following characteristics of a chromosome would identify it as a prokaryotic chromosome rather than a eukaryotic chromosome?
It contains A, C, G, and T. It is a circular molecule. It contains double-stranded DNA. It contains histones.
It is a circular molecule.
The process of copying DNA genetic information into the form of RNA is called __________.
Which of the following is NOT involved in the process of translation initiation? mRNA release factors ribosomal subunits tRNAfMet
has a change in the DNA sequence, but the phenotype does not change.
A silent mutation
results in a different sequence of codons.
results in a codon for a different amino acid than was coded for in the original DNA.
mutation creates a stop codon where one did not exist before
Insertions and deletions usually lead to which of the following types of mutations? frameshift mutations pyrimidine dimers base-substitution mutations silent mutations
X rays and gamma rays cause which of the following types of problems in DNA? frameshift mutations physical breaks in chromosomes base-pair substitutions pyrimidine dimers
physical breaks in chromosomes
What was the significance of Frederick Griffith's experiments with Streptococcus pneumoniae? He showed that strain R cells could easily take up capsules released by dead S cells. He showed that the DNA from strain R cells could transform strain S cells. He showed that the DNA from strain S cells could transform strain R cells. He showed that strain R and strain S cells could be killed by heat.
He showed that the DNA from strain S cells could transform strain R cells.
Bacteriophages are important for which of the following processes? translation transduction transcription transformation