Question
Which are two proteins that assist in the unwinding and separation of DNA strands during replication?
A. Helicase and DNA polymerase III
B. DNA gyrase and DNA polymerase I
C. Helicase and DNA primase
D. Single-strand binding protein and DNA gyrase
▶️Answer/Explanation
Ans:D
Question
Which statement applies to tRNA?
A. There is at least one type of tRNA that combines with each known amino acid.
B. One type of tRNA can combine with all of the known amino acids.
C. tRNA carries out its main role within the nucleus.
D. tRNA is produced by the process of translation.
▶️Answer/Explanation
Ans:A
Question
The graph shows results of an experiment by Hershey and Chase in 1952 in which bacteria were infected with a mixture of virus particles labelled with either \({ }^{32} \mathrm{P}\) or \({ }^{35} \mathrm{~S}\). A suspension of the infected bacteria was agitated with a blender, and samples collected from the suspension were centrifuged to record the percentage of isotope remaining on the outside of the cells.
What do curves X and Y represent?
▶️Answer/Explanation
Ans:B
Question
Rosalind Franklin produced X-ray diffraction images of DNA.
Which previously unknown aspect of DNA was deduced from these images?
A. Chromosomes are made of DNA.
B. Deoxyribose sugar is attached to a phosphate group.
C. The base A pairs with T and C with G.
D. The DNA molecule is a double helix.
▶️Answer/Explanation
Ans:D